Make an image follow mouse pointer

Here's my code (not optimized but a full working example):

<head>
<style>
#divtoshow {position:absolute;display:none;color:white;background-color:black}
#onme {width:150px;height:80px;background-color:yellow;cursor:pointer}
</style>
<script type="text/javascript">
var divName = 'divtoshow'; // div that is to follow the mouse (must be position:absolute)
var offX = 15;          // X offset from mouse position
var offY = 15;          // Y offset from mouse position

function mouseX(evt) {if (!evt) evt = window.event; if (evt.pageX) return evt.pageX; else if (evt.clientX)return evt.clientX + (document.documentElement.scrollLeft ?  document.documentElement.scrollLeft : document.body.scrollLeft); else return 0;}
function mouseY(evt) {if (!evt) evt = window.event; if (evt.pageY) return evt.pageY; else if (evt.clientY)return evt.clientY + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop); else return 0;}

function follow(evt) {
    var obj = document.getElementById(divName).style;
    obj.left = (parseInt(mouseX(evt))+offX) + 'px';
    obj.top = (parseInt(mouseY(evt))+offY) + 'px'; 
    }
document.onmousemove = follow;
</script>
</head>
<body>
<div id="divtoshow">test</div>
<br><br>
<div id='onme' onMouseover='document.getElementById(divName).style.display="block"' onMouseout='document.getElementById(divName).style.display="none"'>Mouse over this</div>
</body>

PANIC: Cannot find AVD system path. Please define ANDROID_SDK_ROOT (in windows 10)

For those coming here with a Mac:

I had the same issue and the problem was, I created an emulator with API Level 29 but removed that SDK and installed 28 instead. The emulator that was not able to be launched anymore.

Therefore check the AVD Manager if your emulator really can be launched.

What is the 'override' keyword in C++ used for?

And as an addendum to all answers, FYI: override is not a keyword, but a special kind of identifier! It has meaning only in the context of declaring/defining virtual functions, in other contexts it's just an ordinary identifier. For details read 2.11.2 of The Standard.

#include <iostream>

struct base
{
    virtual void foo() = 0;
};

struct derived : base
{
    virtual void foo() override
    {
        std::cout << __PRETTY_FUNCTION__ << std::endl;
    }
};

int main()
{
    base* override = new derived();
    override->foo();
    return 0;
}

Output:

zaufi@gentop /work/tests $ g++ -std=c++11 -o override-test override-test.cc
zaufi@gentop /work/tests $ ./override-test
virtual void derived::foo()

pull access denied repository does not exist or may require docker login

I had this because I inadvertantly remove the AS tag from my first image:

ex:

FROM mcr.microsoft.com/windows/servercore:1607-KB4546850-amd64
...
.. etc ...
...
FROM mcr.microsoft.com/windows/servercore:1607-KB4546850-amd64
COPY --from=installer ["/dotnet", "/Program Files/dotnet"]
... etc ...

should have been:

FROM mcr.microsoft.com/windows/servercore:1607-KB4546850-amd64 AS installer
...
.. etc ...
...
FROM mcr.microsoft.com/windows/servercore:1607-KB4546850-amd64
COPY --from=installer ["/dotnet", "/Program Files/dotnet"]
... etc ...

What does AND 0xFF do?

Anding an integer with 0xFF leaves only the least significant byte. For example, to get the first byte in a short s, you can write s & 0xFF. This is typically referred to as "masking". If byte1 is either a single byte type (like uint8_t) or is already less than 256 (and as a result is all zeroes except for the least significant byte) there is no need to mask out the higher bits, as they are already zero.

See ~~tristopia~~Patrick Schlüter's answer below when you may be working with signed types. When doing bitwise operations, I recommend working only with unsigned types.

Creating a segue programmatically

I'd like to add a clarification...

A common misunderstanding, in fact one that I had for some time, is that a storyboard segue is triggered by the prepareForSegue:sender: method. It is not. A storyboard segue will perform, regardless of whether you have implemented a prepareForSegue:sender: method for that (departing from) view controller.

I learnt this from Paul Hegarty's excellent iTunesU lectures. My apologies but unfortunately cannot remember which lecture.

If you connect a segue between two view controllers in a storyboard, but do not implement a prepareForSegue:sender: method, the segue will still segue to the target view controller. It will however segue to that view controller unprepared.

Hope this helps.

Reading a resource file from within jar

Make sure that you work with the correct separator. I replaced all / in a relative path with a File.separator. This worked fine in the IDE, however did not work in the build JAR.

Create 3D array using Python

def n_arr(n, default=0, size=1):
    if n is 0:
        return default

    return [n_arr(n-1, default, size) for _ in range(size)]

arr = n_arr(3, 42, 3)
assert arr[2][2][2], 42

ORA-01882: timezone region not found

I was able to solve the same issue by setting the timezone in my linux system (Centos6.5).

Reposting from

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/set-time.html

set timezone in /etc/sysconfig/clock e.g. set to ZONE="America/Los_Angeles"
sudo ln -sf /usr/share/zoneinfo/America/Phoenix /etc/localtime

To figure out the timezone value try to

ls /usr/share/zoneinfo

and look for the file that represents your timezone.

Once you've set these reboot the machine and try again.

How to get JavaScript caller function line number? How to get JavaScript caller source URL?

console.log(new Error);

It will show you the whole track.

Trim specific character from a string

If you're dealing with longer strings I believe this should outperform most of the other options by reducing the number of allocated strings to either zero or one:

function trim(str, ch) {
    var start = 0, 
        end = str.length;

    while(start < end && str[start] === ch)
        ++start;

    while(end > start && str[end - 1] === ch)
        --end;

    return (start > 0 || end < str.length) ? str.substring(start, end) : str;
}

// Usage:
trim('|hello|world|', '|'); // => 'hello|world'

Or if you want to trim from a set of multiple characters:

function trimAny(str, chars) {
    var start = 0, 
        end = str.length;

    while(start < end && chars.indexOf(str[start]) >= 0)
        ++start;

    while(end > start && chars.indexOf(str[end - 1]) >= 0)
        --end;

    return (start > 0 || end < str.length) ? str.substring(start, end) : str;
}

// Usage:
trimAny('|hello|world   ', [ '|', ' ' ]); // => 'hello|world'
// because '.indexOf' is used, you could also pass a string for the 2nd parameter:
trimAny('|hello| world  ', '| '); // => 'hello|world'

EDIT: For fun, trim words (rather than individual characters)

// Helper function to detect if a string contains another string
//     at a specific position. 
// Equivalent to using `str.indexOf(substr, pos) === pos` but *should* be more efficient on longer strings as it can exit early (needs benchmarks to back this up).
function hasSubstringAt(str, substr, pos) {
    var idx = 0, len = substr.length;

    for (var max = str.length; idx < len; ++idx) {
        if ((pos + idx) >= max || str[pos + idx] != substr[idx])
            break;
    }

    return idx === len;
}

function trimWord(str, word) {
    var start = 0,
        end = str.length,
        len = word.length;

    while (start < end && hasSubstringAt(str, word, start))
        start += word.length;

    while (end > start && hasSubstringAt(str, word, end - len))
        end -= word.length

    return (start > 0 || end < str.length) ? str.substring(start, end) : str;
}

// Usage:
trimWord('blahrealmessageblah', 'blah');

How can you strip non-ASCII characters from a string? (in C#)

If you want not to strip, but to actually convert latin accented to non-accented characters, take a look at this question: How do I translate 8bit characters into 7bit characters? (i.e. Ü to U)

What Scala web-frameworks are available?

I find Unfiltered very interesting https://github.com/unfiltered/unfiltered.

It's mentioned in IttayD's list.

Here is a presentation about it http://unfiltered.lessis.me/#0 and the video http://code.technically.us/post/942531598/doug-tangren-presents-the-unfiltered-toolkit-for

Also here there is an article with more info http://code.technically.us/post/998251172/holding-the-parameter

How to start up spring-boot application via command line?

If you're using gradle, you can use:

./gradlew bootRun

Populating a dictionary using for loops (python)

>>> dict(zip(keys, values))
{0: 'Hi', 1: 'I', 2: 'am', 3: 'John'}

Using getopts to process long and short command line options

getopt and getopts are different beasts, and people seem to have a bit of misunderstanding of what they do. getopts is a built-in command to bash to process command-line options in a loop and assign each found option and value in turn to built-in variables, so you can further process them. getopt, however, is an external utility program, and it doesn't actually process your options for you the way that e.g. bash getopts, the Perl Getopt module or the Python optparse/argparse modules do. All that getopt does is canonicalize the options that are passed in — i.e. convert them to a more standard form, so that it's easier for a shell script to process them. For example, an application of getopt might convert the following:

myscript -ab infile.txt -ooutfile.txt

into this:

myscript -a -b -o outfile.txt infile.txt

You have to do the actual processing yourself. You don't have to use getopt at all if you make various restrictions on the way you can specify options:

only put one option per argument;
all options go before any positional parameters (i.e. non-option arguments);
for options with values (e.g. -o above), the value has to go as a separate argument (after a space).

Why use getopt instead of getopts? The basic reason is that only GNU getopt gives you support for long-named command-line options.¹ (GNU getopt is the default on Linux. Mac OS X and FreeBSD come with a basic and not-very-useful getopt, but the GNU version can be installed; see below.)

For example, here's an example of using GNU getopt, from a script of mine called javawrap:

# NOTE: This requires GNU getopt.  On Mac OS X and FreeBSD, you have to install this
# separately; see below.
TEMP=`getopt -o vdm: --long verbose,debug,memory:,debugfile:,minheap:,maxheap: \
             -n 'javawrap' -- "$@"`

if [ $? != 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi

# Note the quotes around `$TEMP': they are essential!
eval set -- "$TEMP"

VERBOSE=false
DEBUG=false
MEMORY=
DEBUGFILE=
JAVA_MISC_OPT=
while true; do
  case "$1" in
    -v | --verbose ) VERBOSE=true; shift ;;
    -d | --debug ) DEBUG=true; shift ;;
    -m | --memory ) MEMORY="$2"; shift 2 ;;
    --debugfile ) DEBUGFILE="$2"; shift 2 ;;
    --minheap )
      JAVA_MISC_OPT="$JAVA_MISC_OPT -XX:MinHeapFreeRatio=$2"; shift 2 ;;
    --maxheap )
      JAVA_MISC_OPT="$JAVA_MISC_OPT -XX:MaxHeapFreeRatio=$2"; shift 2 ;;
    -- ) shift; break ;;
    * ) break ;;
  esac
done

This lets you specify options like --verbose -dm4096 --minh=20 --maxhe 40 --debugfi="/Users/John Johnson/debug.txt" or similar. The effect of the call to getopt is to canonicalize the options to --verbose -d -m 4096 --minheap 20 --maxheap 40 --debugfile "/Users/John Johnson/debug.txt" so that you can more easily process them. The quoting around "$1" and "$2" is important as it ensures that arguments with spaces in them get handled properly.

If you delete the first 9 lines (everything up through the eval set line), the code will still work! However, your code will be much pickier in what sorts of options it accepts: In particular, you'll have to specify all options in the "canonical" form described above. With the use of getopt, however, you can group single-letter options, use shorter non-ambiguous forms of long-options, use either the --file foo.txt or --file=foo.txt style, use either the -m 4096 or -m4096 style, mix options and non-options in any order, etc. getopt also outputs an error message if unrecognized or ambiguous options are found.

NOTE: There are actually two totally different versions of getopt, basic getopt and GNU getopt, with different features and different calling conventions.² Basic getopt is quite broken: Not only does it not handle long options, it also can't even handle embedded spaces inside of arguments or empty arguments, whereas getopts does do this right. The above code will not work in basic getopt. GNU getopt is installed by default on Linux, but on Mac OS X and FreeBSD it needs to be installed separately. On Mac OS X, install MacPorts (http://www.macports.org) and then do sudo port install getopt to install GNU getopt (usually into /opt/local/bin), and make sure that /opt/local/bin is in your shell path ahead of /usr/bin. On FreeBSD, install misc/getopt.

A quick guide to modifying the example code for your own program: Of the first few lines, all is "boilerplate" that should stay the same, except the line that calls getopt. You should change the program name after -n, specify short options after -o, and long options after --long. Put a colon after options that take a value.

Finally, if you see code that has just set instead of eval set, it was written for BSD getopt. You should change it to use the eval set style, which works fine with both versions of getopt, while the plain set doesn't work right with GNU getopt.

¹Actually, getopts in ksh93 supports long-named options, but this shell isn't used as often as bash. In zsh, use zparseopts to get this functionality.

²Technically, "GNU getopt" is a misnomer; this version was actually written for Linux rather than the GNU project. However, it follows all the GNU conventions, and the term "GNU getopt" is commonly used (e.g. on FreeBSD).

How to check whether a str(variable) is empty or not?

Just say if s or if not s. As in

s = ''
if not s:
    print 'not', s

So in your specific example, if I understand it correctly...

>>> import random
>>> l = ['', 'foo', '', 'bar']
>>> def default_str(l):
...     s = random.choice(l)
...     if not s:
...         print 'default'
...     else:
...         print s
... 
>>> default_str(l)
default
>>> default_str(l)
default
>>> default_str(l)
bar
>>> default_str(l)
default

How to force input to only allow Alpha Letters?

Nice one-liner HTML only:

 <input type="text" id='nameInput' onkeypress='return ((event.charCode >= 65 && event.charCode <= 90) || (event.charCode >= 97 && event.charCode <= 122) || (event.charCode == 32))'>

Table with table-layout: fixed; and how to make one column wider

What you could do is something like this (pseudocode):

<container table>
  <tr>
    <td>
      <"300px" table>
    <td>
      <fixed layout table>

Basically, split up the table into two tables and have it contained by another table.

Joining Multiple Tables - Oracle

While former answer is absolutely correct, I prefer using the JOIN ON syntax to be sure that I know how do I join and on what fields. It would look something like this:

SELECT bc.firstname, bc.lastname, b.title, TO_CHAR(bo.orderdate, 'MM/DD/YYYY') "Order         Date", p.publishername
FROM books b
JOIN book_customer bc ON bc.costumer_id = b.book_id
LEFT JOIN book_order bo ON bo.book_id = b.book_id
(etc.)
WHERE b.publishername = 'PRINTING IS US';

This syntax seperates completely the WHERE clause from the JOIN clause, making the statement more readable and easier for you to debug.

How to specify test directory for mocha?

I am on Windows 7 using node.js v0.10.0 and mocha v1.8.2 and npm v1.2.14. I was just trying to get mocha to use the path test/unit to find my tests, After spending to long and trying several things I landed,

Using the "test/unit/*.js" option does not work on windows. For good reasons that windows shell doesn't expand wildcards like unixen.

However using "test/unit" does work, without the file pattern. eg. "mocha test/unit" runs all files found in test/unit folder.

This only still runs one folder files as tests but you can pass multiple directory names as parameters.

Also to run a single test file you can specify the full path and filename. eg. "mocha test/unit/mytest1.js"

I actually setup in package.json for npm "scripts": { "test": "mocha test/unit" },

So that 'npm test' runs my unit tests.

How Spring Security Filter Chain works

Spring security is a filter based framework, it plants a WALL(HttpFireWall) before your application in terms of proxy filters or spring managed beans. Your request has to pass through multiple filters to reach your API.

Sequence of execution in Spring Security

WebAsyncManagerIntegrationFilter Provides integration between the SecurityContext and Spring Web's WebAsyncManager.
SecurityContextPersistenceFilter This filter will only execute once per request, Populates the SecurityContextHolder with information obtained from the configured SecurityContextRepository prior to the request and stores it back in the repository once the request has completed and clearing the context holder.
Request is checked for existing session. If new request, SecurityContext will be created else if request has session then existing security-context will be obtained from respository.
HeaderWriterFilter Filter implementation to add headers to the current response.
LogoutFilter If request url is /logout(for default configuration) or if request url mathces RequestMatcher configured in LogoutConfigurer then
- clears security context.
- invalidates the session
- deletes all the cookies with cookie names configured in LogoutConfigurer
- Redirects to default logout success url / or logout success url configured or invokes logoutSuccessHandler configured.
UsernamePasswordAuthenticationFilter
- For any request url other than loginProcessingUrl this filter will not process further but filter chain just continues.
- If requested URL is matches(must be HTTP POST) default /login or matches .loginProcessingUrl() configured in FormLoginConfigurer then UsernamePasswordAuthenticationFilter attempts authentication.
- default login form parameters are username and password, can be overridden by usernameParameter(String), passwordParameter(String).
- setting .loginPage() overrides defaults
- While attempting authentication
  - an Authentication object(UsernamePasswordAuthenticationToken or any implementation of Authentication in case of your custom auth filter) is created.
  - and authenticationManager.authenticate(authToken) will be invoked
  - Note that we can configure any number of AuthenticationProvider authenticate method tries all auth providers and checks any of the auth provider supports authToken/authentication object, supporting auth provider will be used for authenticating. and returns Authentication object in case of successful authentication else throws AuthenticationException.
- If authentication success session will be created and authenticationSuccessHandler will be invoked which redirects to the target url configured(default is /)
- If authentication failed user becomes un-authenticated user and chain continues.
SecurityContextHolderAwareRequestFilter, if you are using it to install a Spring Security aware HttpServletRequestWrapper into your servlet container
AnonymousAuthenticationFilter Detects if there is no Authentication object in the SecurityContextHolder, if no authentication object found, creates Authentication object (AnonymousAuthenticationToken) with granted authority ROLE_ANONYMOUS. Here AnonymousAuthenticationToken facilitates identifying un-authenticated users subsequent requests.

_{Debug logs}

DEBUG - /app/admin/app-config at position 9 of 12 in additional filter chain; firing Filter: 'AnonymousAuthenticationFilter'
DEBUG - Populated SecurityContextHolder with anonymous token: 'org.springframework.security.authentication.AnonymousAuthenticationToken@aeef7b36: Principal: anonymousUser; Credentials: [PROTECTED]; Authenticated: true; Details: org.springframework.security.web.authentication.WebAuthenticationDetails@b364: RemoteIpAddress: 0:0:0:0:0:0:0:1; SessionId: null; Granted Authorities: ROLE_ANONYMOUS'

ExceptionTranslationFilter, to catch any Spring Security exceptions so that either an HTTP error response can be returned or an appropriate AuthenticationEntryPoint can be launched
FilterSecurityInterceptor
There will be FilterSecurityInterceptor which comes almost last in the filter chain which gets Authentication object from SecurityContext and gets granted authorities list(roles granted) and it will make a decision whether to allow this request to reach the requested resource or not, decision is made by matching with the allowed AntMatchers configured in HttpSecurityConfiguration.

Consider the exceptions 401-UnAuthorized and 403-Forbidden. These decisions will be done at the last in the filter chain

Un authenticated user trying to access public resource - Allowed
Un authenticated user trying to access secured resource - 401-UnAuthorized
Authenticated user trying to access restricted resource(restricted for his role) - 403-Forbidden

Note: User Request flows not only in above mentioned filters, but there are others filters too not shown here.(ConcurrentSessionFilter,RequestCacheAwareFilter,SessionManagementFilter ...)
It will be different when you use your custom auth filter instead of UsernamePasswordAuthenticationFilter.
It will be different if you configure JWT auth filter and omit .formLogin() i.e, UsernamePasswordAuthenticationFilter it will become entirely different case.

Just For reference. Filters in spring-web and spring-security
Note: refer package name in pic, as there are some other filters from orm and my custom implemented filter.

From Documentation ordering of filters is given as

ChannelProcessingFilter

ConcurrentSessionFilter

SecurityContextPersistenceFilter

LogoutFilter

X509AuthenticationFilter

AbstractPreAuthenticatedProcessingFilter

CasAuthenticationFilter

UsernamePasswordAuthenticationFilter

ConcurrentSessionFilter

OpenIDAuthenticationFilter

DefaultLoginPageGeneratingFilter

DefaultLogoutPageGeneratingFilter

ConcurrentSessionFilter

DigestAuthenticationFilter

BearerTokenAuthenticationFilter

BasicAuthenticationFilter

RequestCacheAwareFilter

SecurityContextHolderAwareRequestFilter

JaasApiIntegrationFilter

RememberMeAuthenticationFilter

AnonymousAuthenticationFilter

SessionManagementFilter

ExceptionTranslationFilter

FilterSecurityInterceptor

SwitchUserFilter

You can also refer
most common way to authenticate a modern web app?
difference between authentication and authorization in context of Spring Security?

Implicit type conversion rules in C++ operators

My solution to the problem got WA(wrong answer), then i changed one of int to long long int and it gave AC(accept). Previously, I was trying to do long long int += int * int, and after I rectify it to long long int += long long int * int. Googling I came up with,

1. Arithmetic Conversions

Conditions for Type Conversion:

Conditions Met ---> Conversion

Either operand is of type long double. ---> Other operand is converted to type long double.
Preceding condition not met and either operand is of type double. ---> Other operand is converted to type double.
Preceding conditions not met and either operand is of type float. ---> Other operand is converted to type float.
Preceding conditions not met (none of the operands are of floating types). ---> Integral promotions are performed on the operands as follows:
- If either operand is of type unsigned long, the other operand is converted to type unsigned long.
- If preceding condition not met, and if either operand is of type long and the other of type unsigned int, both operands are converted to type unsigned long.
- If the preceding two conditions are not met, and if either operand is of type long, t he other operand is converted to type long.
- If the preceding three conditions are not met, and if either operand is of type unsigned int, the other operand is converted to type unsigned int.
- If none of the preceding conditions are met, both operands are converted to type int.

2 . Integer conversion rules

Integer Promotions:

Integer types smaller than int are promoted when an operation is performed on them. If all values of the original type can be represented as an int, the value of the smaller type is converted to an int; otherwise, it is converted to an unsigned int. Integer promotions are applied as part of the usual arithmetic conversions to certain argument expressions; operands of the unary +, -, and ~ operators; and operands of the shift operators.

Integer Conversion Rank:
- No two signed integer types shall have the same rank, even if they have the same representation.
- The rank of a signed integer type shall be greater than the rank of any signed integer type with less precision.
- The rank of long long int shall be greater than the rank of long int, which shall be greater than the rank of int, which shall be greater than the rank of short int, which shall be greater than the rank of signed char.
- The rank of any unsigned integer type shall equal the rank of the corresponding signed integer type, if any.
- The rank of any standard integer type shall be greater than the rank of any extended integer type with the same width.
- The rank of char shall equal the rank of signed char and unsigned char.
- The rank of any extended signed integer type relative to another extended signed integer type with the same precision is implementation-defined but still subject to the other rules for determining the integer conversion rank.
- For all integer types T1, T2, and T3, if T1 has greater rank than T2 and T2 has greater rank than T3, then T1 has greater rank than T3.
Usual Arithmetic Conversions:
- If both operands have the same type, no further conversion is needed.
- If both operands are of the same integer type (signed or unsigned), the operand with the type of lesser integer conversion rank is converted to the type of the operand with greater rank.
- If the operand that has unsigned integer type has rank greater than or equal to the rank of the type of the other operand, the operand with signed integer type is converted to the type of the operand with unsigned integer type.
- If the type of the operand with signed integer type can represent all of the values of the type of the operand with unsigned integer type, the operand with unsigned integer type is converted to the type of the operand with signed integer type.
- Otherwise, both operands are converted to the unsigned integer type corresponding to the type of the operand with signed integer type. Specific operations can add to or modify the semantics of the usual arithmetic operations.

error: No resource identifier found for attribute 'adSize' in package 'com.google.example' main.xml

Based on the answer here, I think you need to change the xmlns:ads attribute. For example, change this:

<com.google.ads.AdView 
    xmlns:ads="http://schemas.android.com/apk/res/com.google.example"
    ...
    />

to this:

<com.google.ads.AdView
    xmlns:ads="http://schemas.android.com/apk/res/com.your.app.namespace" 
    ... 
    />

It fixed it for me. If you're still getting errors, could you elaborate?

Setting HttpContext.Current.Session in a unit test

I was looking for something a little less invasive than the options mentioned above. In the end I came up with a cheesy solution, but it might get some folks moving a little faster.

First I created a TestSession class:

class TestSession : ISession
{

    public TestSession()
    {
        Values = new Dictionary<string, byte[]>();
    }

    public string Id
    {
        get
        {
            return "session_id";
        }
    }

    public bool IsAvailable
    {
        get
        {
            return true;
        }
    }

    public IEnumerable<string> Keys
    {
        get { return Values.Keys; }
    }

    public Dictionary<string, byte[]> Values { get; set; }

    public void Clear()
    {
        Values.Clear();
    }

    public Task CommitAsync()
    {
        throw new NotImplementedException();
    }

    public Task LoadAsync()
    {
        throw new NotImplementedException();
    }

    public void Remove(string key)
    {
        Values.Remove(key);
    }

    public void Set(string key, byte[] value)
    {
        if (Values.ContainsKey(key))
        {
            Remove(key);
        }
        Values.Add(key, value);
    }

    public bool TryGetValue(string key, out byte[] value)
    {
        if (Values.ContainsKey(key))
        {
            value = Values[key];
            return true;
        }
        value = new byte[0];
        return false;
    }
}

Then I added an optional parameter to my controller's constructor. If the parameter is present, use it for session manipulation. Otherwise, use the HttpContext.Session:

class MyController
{

    private readonly ISession _session;

    public MyController(ISession session = null)
    {
        _session = session;
    }


    public IActionResult Action1()
    {
        Session().SetString("Key", "Value");
        View();
    }

    public IActionResult Action2()
    {
        ViewBag.Key = Session().GetString("Key");
        View();
    }

    private ISession Session()
    {
        return _session ?? HttpContext.Session;
    }
}

Now I can inject my TestSession into the controller:

class MyControllerTest
{

    private readonly MyController _controller;

    public MyControllerTest()
    {
        var testSession = new TestSession();
        var _controller = new MyController(testSession);
    }
}

When should you use constexpr capability in C++11?

All of the other answers are great, I just want to give a cool example of one thing you can do with constexpr that is amazing. See-Phit (https://github.com/rep-movsd/see-phit/blob/master/seephit.h) is a compile time HTML parser and template engine. This means you can put HTML in and get out a tree that is able to be manipulated. Having the parsing done at compile time can give you a bit of extra performance.

From the github page example:

#include <iostream>
#include "seephit.h"
using namespace std;



int main()
{
  constexpr auto parser =
    R"*(
    <span >
    <p  color="red" height='10' >{{name}} is a {{profession}} in {{city}}</p  >
    </span>
    )*"_html;

  spt::tree spt_tree(parser);

  spt::template_dict dct;
  dct["name"] = "Mary";
  dct["profession"] = "doctor";
  dct["city"] = "London";

  spt_tree.root.render(cerr, dct);
  cerr << endl;

  dct["city"] = "New York";
  dct["name"] = "John";
  dct["profession"] = "janitor";

  spt_tree.root.render(cerr, dct);
  cerr << endl;
}

How to resize array in C++?

Use std::vector or
Write your own method. Allocate chunk of memory using new. with that memory you can expand till the limit of memory chunk.

Regular Expression for alphabets with spaces

Change placeholder text

var input = document.getElementById ("IdofInput");
input.placeholder = "No need to fill this field";

You can find out more about placeholder here: http://help.dottoro.com/ljgugboo.php

Check if a input box is empty

The above answer didn't work with Angular 6. So following is how I resolved it. Lets say this is how I defined my input box -

_x000D_

<input type="number" id="myTextBox" name="myTextBox"_x000D_
 [(ngModel)]="response.myTextBox"_x000D_
            #myTextBox="ngModel">

_x000D_

To check if the field is empty or not this should be the script.

_x000D_

<div *ngIf="!myTextBox.value" style="color:red;">_x000D_
 Your field is empty_x000D_
</div>

_x000D_

Do note the subtle difference between the above answer and this answer. I have added an additional attribute .value after my input name myTextBox. I don't know if the above answer worked for above version of Angular, but for Angular 6 this is how it should be done.

Some more explanation on why this check works; when there is no value present in the input box the default value of myTextBox.value will be undefined. As soon as you enter some text, your text becomes the new value of myTextBox.value.

When your check is !myTextBox.value it is checking that the value is undefined or not, it is equivalent to myTextBox.value == undefined.

Python element-wise tuple operations like sum

This solution doesn't require an import:

tuple(map(lambda x, y: x + y, tuple1, tuple2))

How Can I Download a File from EC2

How to upload file to server with HTTP POST multipart/form-data?

It work for window phone 8.1. You can try this.

Dictionary<string, object> _headerContents = new Dictionary<string, object>();
const String _lineEnd = "\r\n";
const String _twoHyphens = "--";
const String _boundary = "*****";
private async void UploadFile_OnTap(object sender, System.Windows.Input.GestureEventArgs e)
{
   Uri serverUri = new Uri("http:www.myserver.com/Mp4UploadHandler", UriKind.Absolute);    
   string fileContentType = "multipart/form-data";       
   byte[] _boundarybytes = Encoding.UTF8.GetBytes(_twoHyphens + _boundary + _lineEnd);
   byte[] _trailerbytes = Encoding.UTF8.GetBytes(_twoHyphens + _boundary + _twoHyphens + _lineEnd);
   Dictionary<string, object> _headerContents = new Dictionary<string, object>();
   SetEndHeaders();  // to add some extra parameter if you need

   httpWebRequest = (HttpWebRequest)WebRequest.Create(serverUri);
   httpWebRequest.ContentType = fileContentType + "; boundary=" + _boundary;
   httpWebRequest.Method = "POST";
   httpWebRequest.AllowWriteStreamBuffering = false;  // get response after upload header part

   var fileName = Path.GetFileName(MediaStorageFile.Path);    
   Stream fStream = (await MediaStorageFile.OpenAsync(Windows.Storage.FileAccessMode.Read)).AsStream(); //MediaStorageFile is a storage file from where you want to upload the file of your device    
   string fileheaderTemplate = "Content-Disposition: form-data; name=\"{0}\"" + _lineEnd + _lineEnd + "{1}" + _lineEnd;    
   long httpLength = 0;
   foreach (var headerContent in _headerContents) // get the length of upload strem
   httpLength += _boundarybytes.Length + Encoding.UTF8.GetBytes(string.Format(fileheaderTemplate, headerContent.Key, headerContent.Value)).Length;

   httpLength += _boundarybytes.Length + Encoding.UTF8.GetBytes("Content-Disposition: form-data; name=\"uploadedFile\";filename=\"" + fileName + "\"" + _lineEnd).Length
                                       + Encoding.UTF8.GetBytes(_lineEnd).Length * 2 + _trailerbytes.Length;
   httpWebRequest.ContentLength = httpLength + fStream.Length;  // wait until you upload your total stream 

    httpWebRequest.BeginGetRequestStream((result) =>
    {
       try
       {
         HttpWebRequest request = (HttpWebRequest)result.AsyncState;
         using (Stream stream = request.EndGetRequestStream(result))
         {
            foreach (var headerContent in _headerContents)
            {
               WriteToStream(stream, _boundarybytes);
               WriteToStream(stream, string.Format(fileheaderTemplate, headerContent.Key, headerContent.Value));
             }

             WriteToStream(stream, _boundarybytes);
             WriteToStream(stream, "Content-Disposition: form-data; name=\"uploadedFile\";filename=\"" + fileName + "\"" + _lineEnd);
             WriteToStream(stream, _lineEnd);

             int bytesRead = 0;
             byte[] buffer = new byte[2048];  //upload 2K each time

             while ((bytesRead = fStream.Read(buffer, 0, buffer.Length)) != 0)
             {
               stream.Write(buffer, 0, bytesRead);
               Array.Clear(buffer, 0, 2048); // Clear the array.
              }

              WriteToStream(stream, _lineEnd);
              WriteToStream(stream, _trailerbytes);
              fStream.Close();
         }
         request.BeginGetResponse(a =>
         { //get response here
            try
            {
               var response = request.EndGetResponse(a);
               using (Stream streamResponse = response.GetResponseStream())
               using (var memoryStream = new MemoryStream())
               {   
                   streamResponse.CopyTo(memoryStream);
                   responseBytes = memoryStream.ToArray();  // here I get byte response from server. you can change depends on server response
               }    
              if (responseBytes.Length > 0 && responseBytes[0] == 1)
                 MessageBox.Show("Uploading Completed");
              else
                  MessageBox.Show("Uploading failed, please try again.");
            }
            catch (Exception ex)
            {}
          }, null);
      }
      catch (Exception ex)
      {
         fStream.Close();                             
      }
   }, httpWebRequest);
}

private static void WriteToStream(Stream s, string txt)
{
   byte[] bytes = Encoding.UTF8.GetBytes(txt);
   s.Write(bytes, 0, bytes.Length);
 }

 private static void WriteToStream(Stream s, byte[] bytes)
 {
   s.Write(bytes, 0, bytes.Length);
 }

 private void SetEndHeaders()
 {
   _headerContents.Add("sId", LocalData.currentUser.SessionId);
   _headerContents.Add("uId", LocalData.currentUser.UserIdentity);
   _headerContents.Add("authServer", LocalData.currentUser.AuthServerIP);
   _headerContents.Add("comPort", LocalData.currentUser.ComPort);
 }

Can I grep only the first n lines of a file?

The magic of pipes;

head -10 log.txt | grep <whatever>

How do I check to see if my array includes an object?

#include? should work, it works for general objects, not only strings. Your problem in example code is this test:

unless @suggested_horses.exists?(horse.id)
  @suggested_horses<< horse
end

(even assuming using #include?). You try to search for specific object, not for id. So it should be like this:

unless @suggested_horses.include?(horse)
  @suggested_horses << horse
end

ActiveRecord has redefined comparision operator for objects to take a look only for its state (new/created) and id

How do you get current active/default Environment profile programmatically in Spring?

To tweak a bit in order to handle the case where the variable is not set you could use a default value:

@Value("${spring.profiles.active:unknown}")
private String activeProfile;

This way if spring.profiles.active is set, it will take it else it will take the default value unknown.

So no exception will be triggered. And no need to force add something like @ActiveProfiles("test") in your test to make it pass.

Returning a value from callback function in Node.js

If what you want is to get your code working without modifying too much. You can try this solution which gets rid of callbacks and keeps the same code workflow:

Given that you are using Node.js, you can use co and co-request to achieve the same goal without callback concerns.

Basically, you can do something like this:

function doCall(urlToCall) {
  return co(function *(){
    var response = yield urllib.request(urlToCall, { wd: 'nodejs' }); // This is co-request.                             
    var statusCode = response.statusCode;
    finalData = getResponseJson(statusCode, data.toString());
    return finalData;
  });
}

Then,

var response = yield doCall(urlToCall); // "yield" garuantees the callback finished.
console.log(response) // The response will not be undefined anymore.

By doing this, we wait until the callback function finishes, then get the value from it. Somehow, it solves your problem.

Use CSS to automatically add 'required field' asterisk to form inputs

For those who end up here, but have jQuery:

// javascript / jQuery
$("label.required").append('<span class="red-star"> *</span>')

// css
.red-star { color: red; }

Git for beginners: The definitive practical guide

GUIs for git

Git GUI

Included with git — Run git gui from the command line, and the Windows msysgit installer adds it to the Start menu.

Git GUI can do a majority of what you'd need to do with git. Including stage changes, configure git and repositories, push changes, create/checkout/delete branches, merge, and many other things.

One of my favourite features is the "stage line" and "stage hunk" shortcuts in the right-click menu, which lets you commit specific parts of a file. You can achieve the same via git add -i, but I find it easier to use.

It isn't the prettiest application, but it works on almost all platforms (being based upon Tcl/Tk)

Screenshots | a screencast

GitK

Also included with git. It is a git history viewer, and lets you visualise a repository's history (including branches, when they are created, and merged). You can view and search commits.

Goes together nicely with git-gui.

Gitnub

Mac OS X application. Mainly an equivalent of git log, but has some integration with github (like the "Network view").

Looks pretty, and fits with Mac OS X. You can search repositories. The biggest critisism of Gitnub is that it shows history in a linear fashion (a single branch at a time) - it doesn't visualise branching and merging, which can be important with git, although this is a planned improvement.

Download links, change log and screenshots | git repository

GitX

Intends to be a "gitk clone for OS X".

It can visualise non-linear branching history, perform commits, view and search commits, and it has some other nice features like being able to "Quicklook" any file in any revision (press space in the file-list view), export any file (via drag and drop).

It is far better integrated into OS X than git-gui/gitk, and is fast and stable even with exceptionally large repositories.

The original git repository pieter has not updated recently (over a year at time of writing). A more actively maintained branch is available at brotherbard/gitx - it adds "sidebar, fetch, pull, push, add remote, merge, cherry-pick, rebase, clone, clone to"

Download | Screenshots | git repository | brotherbard fork | laullon fork

SmartGit

From the homepage:

SmartGit is a front-end for the distributed version control system Git and runs on Windows, Mac OS X and Linux. SmartGit is intended for developers who prefer a graphical user interface over a command line client, to be even more productive with Git — the most powerful DVCS today.

You can download it from their website.

Download

TortoiseGit

TortoiseSVN Git version for Windows users.

It is porting TortoiseSVN to TortoiseGit The latest release 1.2.1.0 This release can complete regular task, such commit, show log, diff two version, create branch and tag, Create patch and so on. See ReleaseNotes for detail. Welcome to contribute this project.

Download

QGit

QGit is a git GUI viewer built on Qt/C++.

With qgit you will be able to browse revisions history, view patch content and changed files, graphically following different development branches.

Download

gitg

gitg is a git repository viewer targeting gtk+/GNOME. One of its main objectives is to provide a more unified user experience for git frontends across multiple desktops. It does this not be writing a cross-platform application, but by close collaboration with similar clients for other operating systems (like GitX for OS X).

Features

Browse revision history.
Handle large repositories (loads linux repository, 17000+ revisions, under 1 second).
Commit changes.
Stage/unstage individual hunks.
Revert changes.
Show colorized diff of changes in revisions.
Browse tree for a given revision.
Export parts of the tree of a given revision.
Supply any refspec which a command such as 'git log' can understand to built the history.
Show and switch between branches in the history view.

Download: releases or source

Gitbox

Gitbox is a Mac OS X graphical interface for Git version control system. In a single window you see branches, history and working directory status.

Everyday operations are easy: stage and unstage changes with a checkbox. Commit, pull, merge and push with a single click. Double-click a change to show a diff with FileMerge.app.

Download

Gity

The Gity website doesn't have much information, but from the screenshots on there it appears to be a feature rich open source OS X git gui.

Download or source

Meld

Meld is a visual diff and merge tool. You can compare two or three files and edit them in place (diffs update dynamically). You can compare two or three folders and launch file comparisons. You can browse and view a working copy from popular version control systems such such as CVS, Subversion, Bazaar-ng and Mercurial [and Git].

Downloads

Katana

A Git GUIfor OSX by Steve Dekorte.

At a glance, see which remote branches have changes to pull and local repos have changes to push. The git ops of add, commit, push, pull, tag and reset are supported as well as visual diffs and visual browsing of project hieracy that highlights local changes and additions.

Free for 1 repository, $25 for more.

Download

Sprout (formerly GitMac)

Focuses on making Git easy to use. Features a native Cocoa (mac-like) UI, fast repository browsing, cloning, push/pull, branching/merging, visual diff, remote branches, easy access to the Terminal, and more.

By making the most commonly used Git actions intuitive and easy to perform, Sprout (formerly GitMac) makes Git user-friendly. Compatible with most Git workflows, Sprout is great for designers and developers, team collaboration and advanced and novice users alike.

Download | Website

Tower

A feature-rich Git GUI for Mac OSX. 30-day free trial, $59USD for a single-user license.

Download | Website

EGit

EGit is an Eclipse Team provider for the Git version control system. Git is a distributed SCM, which means every developer has a full copy of all history of every revision of the code, making queries against the history very fast and versatile.

The EGit project is implementing Eclipse tooling on top of the JGit Java implementation of Git.

Download | Website

Git Extensions

Open Source for Windows - installs everything you need to work with Git in a single package, easy to use.

Git Extensions is a toolkit to make working with Git on Windows more intuitive. The shell extension will intergrate in Windows Explorer and presents a context menu on files and directories. There is also a Visual Studio plugin to use git from Visual Studio.

Download

Big thanks to dbr for elaborating on the git gui stuff.

SourceTree

SourceTree is a free Mac client for Git, Mercurial and SVN. Built by Atlassian, the folks behind BitBucket, it seems to work equally well with any VC system, which allows you to master a single tool for use with all of your projects, however they're version-controlled. Feature-packed, and FREE.

Expert-Ready & Feature-packed for both novice and advanced users:

Review outgoing and incoming changesets. Cherry-pick between branches. Patch handling, rebase, stash / shelve and much more.

Download | Website

The endpoint reference (EPR) for the Operation not found is

It happens because the source WSDL in each operation has not defined the SOAPAction value.

e.g.

<soap12:operation soapAction="" style="document"/>

His is important for axis server.

If you have created the service on netbeans or another, don't forget to set the value action on the tag @WebMethod

e.g. @WebMethod(action = "hello", operationName = "hello")

This will create the SOAPAction value by itself.

Correct way of getting Client's IP Addresses from http.Request

Here a completely working example

package main

import (  
    // Standard library packages
    "fmt"
    "strconv"
    "log"
    "net"
    "net/http"

    // Third party packages
    "github.com/julienschmidt/httprouter"
    "github.com/skratchdot/open-golang/open"
)



// https://blog.golang.org/context/userip/userip.go
func getIP(w http.ResponseWriter, req *http.Request, _ httprouter.Params){
    fmt.Fprintf(w, "<h1>static file server</h1><p><a href='./static'>folder</p></a>")

    ip, port, err := net.SplitHostPort(req.RemoteAddr)
    if err != nil {
        //return nil, fmt.Errorf("userip: %q is not IP:port", req.RemoteAddr)

        fmt.Fprintf(w, "userip: %q is not IP:port", req.RemoteAddr)
    }

    userIP := net.ParseIP(ip)
    if userIP == nil {
        //return nil, fmt.Errorf("userip: %q is not IP:port", req.RemoteAddr)
        fmt.Fprintf(w, "userip: %q is not IP:port", req.RemoteAddr)
        return
    }

    // This will only be defined when site is accessed via non-anonymous proxy
    // and takes precedence over RemoteAddr
    // Header.Get is case-insensitive
    forward := req.Header.Get("X-Forwarded-For")

    fmt.Fprintf(w, "<p>IP: %s</p>", ip)
    fmt.Fprintf(w, "<p>Port: %s</p>", port)
    fmt.Fprintf(w, "<p>Forwarded for: %s</p>", forward)
}


func main() {  
    myport := strconv.Itoa(10002);


    // Instantiate a new router
    r := httprouter.New()

    r.GET("/ip", getIP)

    // Add a handler on /test
    r.GET("/test", func(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
        // Simply write some test data for now
        fmt.Fprint(w, "Welcome!\n")
    })  


    l, err := net.Listen("tcp", "localhost:" + myport)
    if err != nil {
        log.Fatal(err)
    }
    // The browser can connect now because the listening socket is open.


    //err = open.Start("http://localhost:"+ myport + "/test")
    err = open.Start("http://localhost:"+ myport + "/ip")
    if err != nil {
         log.Println(err)
    }

    // Start the blocking server loop.
    log.Fatal(http.Serve(l, r)) 
}

Property 'value' does not exist on type 'EventTarget'

Here is one more way to specify event.target:

_x000D_

import { Component, EventEmitter, Output } from '@angular/core';_x000D_
_x000D_
@Component({_x000D_
    selector: 'text-editor',_x000D_
    template: `<textarea (keyup)="emitWordCount($event)"></textarea>`_x000D_
})_x000D_
export class TextEditorComponent {_x000D_
_x000D_
   @Output() countUpdate = new EventEmitter<number>();_x000D_
_x000D_
    emitWordCount({ target = {} as HTMLTextAreaElement }) { // <- right there_x000D_
_x000D_
        this.countUpdate.emit(_x000D_
          // using it directly without `event`_x000D_
            (target.value.match(/\S+/g) || []).length);_x000D_
    }_x000D_
}

_x000D_

How to keep one variable constant with other one changing with row in excel

To make your formula more readable, you could assign a Name to cell A0, and then use that name in the formula.

The easiest way to define a Name is to highlight the cell or range, then click on the Name box in the formula bar.

Then, if you named A0 "Rate" you can use that name like this:

=(B0+4)/(Rate)

See, much easier to read.

If you want to find Rate, click F5 and it appears in the GoTo list.

Autoincrement VersionCode with gradle extra properties

Define versionName in AndroidManifest.xml

android:versionName="5.1.5"

Inside android{...} block in build.gradle of app level :

defaultConfig {
        applicationId "com.example.autoincrement"
        minSdkVersion 18
        targetSdkVersion 23
        multiDexEnabled true
        def version = getIncrementationVersionName()
        versionName version
}

Outside android{...} block in build.gradle of app level :

def getIncrementedVersionName() {
    List<String> runTasks = gradle.startParameter.getTaskNames();

    //find version name in manifest
    def manifestFile = file('src/main/AndroidManifest.xml')
    def matcher = Pattern.compile('versionName=\"(\\d+)\\.(\\d+)\\.(\\d+)\"').matcher(manifestFile.getText())
    matcher.find()

    //extract versionName parts
    def firstPart = Integer.parseInt(matcher.group(1))
    def secondPart = Integer.parseInt(matcher.group(2))
    def thirdPart = Integer.parseInt(matcher.group(3))

    //check is runTask release or not
    // if release - increment version
    for (String item : runTasks) {
        if (item.contains("assemble") && item.contains("Release")) {
            thirdPart++
            if (thirdPart == 10) {
                thirdPart = 0;
                secondPart++
                if (secondPart == 10) {
                    secondPart = 0;
                    firstPart++
                }
            }
        }
    }

    def versionName = firstPart + "." + secondPart + "." + thirdPart

    // update manifest
    def manifestContent = matcher.replaceAll('versionName=\"' + versionName + '\"')
    manifestFile.write(manifestContent)

    println "incrementVersionName = " + versionName

    return versionName
}

After create singed APK :

android:versionName="5.1.6"

Note : If your versionName different from my, you need change regex and extract parts logic.

jquery UI dialog: how to initialize without a title bar?

This worked for me:

$("#dialog").dialog({
    create: function (event, ui) {
        $(".ui-widget-header").hide();
    },

How do you find out the caller function in JavaScript?

If you are not going to run it in IE < 11 then console.trace() would suit.

function main() {
    Hello();
}

function Hello() {
    console.trace()
}

main()
// Hello @ VM261:9
// main @ VM261:4

Angular JS Uncaught Error: [$injector:modulerr]

Try adding this:

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.7/angular-resource.min.js"></script>

jQuery or CSS selector to select all IDs that start with some string

try this:

$('div[id^="player_"]')

Remove empty lines in a text file via grep

with awk, just check for number of fields. no need regex

$ more file
hello

world

foo

bar

$ awk 'NF' file
hello
world
foo
bar

How to read text files with ANSI encoding and non-English letters?

If I remember correctly the XmlDocument.Load(string) method always assumes UTF-8, regardless of the XML encoding. You would have to create a StreamReader with the correct encoding and use that as the parameter.

xmlDoc.Load(new StreamReader(
                     File.Open("file.xml"), 
                     Encoding.GetEncoding("iso-8859-15")));

I just stumbled across KB308061 from Microsoft. There's an interesting passage: Specify the encoding declaration in the XML declaration section of the XML document. For example, the following declaration indicates that the document is in UTF-16 Unicode encoding format:

<?xml version="1.0" encoding="UTF-16"?>

Note that this declaration only specifies the encoding format of an XML document and does not modify or control the actual encoding format of the data.

Link Source:

XmlDocument.Load() method fails to decode € (euro)

z-index not working with position absolute

Opacity changes the context of your z-index, as does the static positioning. Either add opacity to the element that doesn't have it or remove it from the element that does. You'll also have to either make both elements static positioned or specify relative or absolute position. Here's some background on contexts: http://philipwalton.com/articles/what-no-one-told-you-about-z-index/

What is the difference between smoke testing and sanity testing?

Smoke Testing

Smoke testing is a wide approach where all areas of the software application are tested without getting into too deep
The test cases for smoke testing of the software can be either manual or automated
Smoke testing is done to ensure whether the main functions of the software application are working or not. During smoke testing of the software, we do not go into finer details.
Smoke testing of the software application is done to check whether the build can be accepted for through software testing
This testing is performed by the developers or testers
Smoke testing exercises the entire system from end to end
Smoke testing is like General Health Check Up
Smoke testing is usually documented or scripted

Santy Testing

Sanity software testing is a narrow regression testing with a focus on one or a small set of areas of functionality of the software application.
Sanity test is generally without test scripts or test cases.
Sanity testing is a cursory software testing type. It is done whenever a quick round of software testing can prove that the software application is functioning according to business / functional requirements.
Sanity testing of the software is to ensure whether the requirements are met or not.
Sanity testing is usually performed by testers
Sanity testing exercises only the particular component of the entire system
Sanity Testing is like specialized health check up
Sanity testing is usually not documented and is unscripted

For more visit Link

newline character in c# string

A great way of handling this is with regular expressions.

string modifiedString = Regex.Replace(originalString, @"(\r\n)|\n|\r", "<br/>");

This will replace any of the 3 legal types of newline with the html tag.

How to finish current activity in Android

I found many answers but not one is simple... I hope this will help you...

try{
    Intent intent = new Intent(CurrentActivity.this, NewActivity.class);
    startActivity(intent);
} finally {
    finish();
}

so, Very simple logic is here, as we know that in java we write code that has some chances of exception in a try block and handle that exception in catch block but in finally block we write code that has to be executed in any cost (Either the exception comes or not).

Listing all permutations of a string/integer

Here is the function which will print all permutations recursively.

public void Permutations(string input, StringBuilder sb)
    {
        if (sb.Length == input.Length)
        {
            Console.WriteLine(sb.ToString());
            return;
        }

        char[] inChar = input.ToCharArray();

        for (int i = 0; i < input.Length; i++)
        {
            if (!sb.ToString().Contains(inChar[i]))
            {
                sb.Append(inChar[i]);
                Permutations(input, sb);    
                RemoveChar(sb, inChar[i]);
            }
        }
    }

private bool RemoveChar(StringBuilder input, char toRemove)
    {
        int index = input.ToString().IndexOf(toRemove);
        if (index >= 0)
        {
            input.Remove(index, 1);
            return true;
        }
        return false;
    }

How to make graphics with transparent background in R using ggplot2?

As for someone don't like gray background like academic editor, try this:

p <- p + theme_bw()
p

How can I change the user on Git Bash?

For Mac Users

I am using Mac and I was facing the same problem while I was trying to push a project from Android Studio. The reason for that is another user had previously logged into GitHub and his credentials were saved in Keychain Access.

The solution is to delete all the information store in keychain for that process

Javascript code for showing yesterday's date and todays date

One liner:

var yesterday = new Date(Date.now() - 864e5); // 864e5 == 86400000 == 24*60*60*1000

How do I modify fields inside the new PostgreSQL JSON datatype?

So, for example my string looks like this: {"a1":{"a11":"x","a22":"y","a33":"z"}}

I update jsons by using temp table, which is good enough for rather small ammounth of data (<1.000.000). I found a different way, but then went on vacation and forgot it...

So. the query will be something like this:

with temp_table as (
select 
a.id,
a->'a1'->>'a11' as 'a11',
a->'a1'->>'a22' as 'a22',
a->'a1'->>'a33' as 'a33',
u1.a11updated
from foo a
join table_with_updates u1 on u1.id = a.id)
    update foo a
    set a = ('{"a1": {"a11": "'|| t.a11updated ||'",
        "a22":"'|| t.a22 ||'",
        "a33":"'|| t.a33 ||'"}}')::jsonb
    from temp_table t
    where t.id = a.id;

It has more to do with string than json, but it works. Basically, it pulls all the data into temp table, creates a string while plugging concat holes with the data you backed up, and converts it into jsonb.

Json_set might be more efficient, but I'm still getting a hang of it. First time I tried to use it, I messed up the string completely...

NodeJS: How to decode base64 encoded string back to binary?

As of Node.js v6.0.0 using the constructor method has been deprecated and the following method should instead be used to construct a new buffer from a base64 encoded string:

var b64string = /* whatever */;
var buf = Buffer.from(b64string, 'base64'); // Ta-da

For Node.js v5.11.1 and below

Construct a new Buffer and pass 'base64' as the second argument:

var b64string = /* whatever */;
var buf = new Buffer(b64string, 'base64'); // Ta-da

If you want to be clean, you can check whether from exists :

if (typeof Buffer.from === "function") {
    // Node 5.10+
    buf = Buffer.from(b64string, 'base64'); // Ta-da
} else {
    // older Node versions, now deprecated
    buf = new Buffer(b64string, 'base64'); // Ta-da
}

Java out.println() how is this possible?

you can see this also in sockets ...

PrintWriter out = new PrintWriter(socket.getOutputStream());

out.println("hello");

converting date time to 24 hour format

kk = Hours in 1-24 format
hh= hours in 1-12 format
KK= hours in 0-11 format
HH= hours in 0-23 format

Invert match with regexp

Build an expression that matches, and use !match()... (logical negation) That's probably how grep does anyway...

Change content of div - jQuery

$('a').click(function(){
 $('#content-container').html('My content here :-)');
});

How to reformat JSON in Notepad++?

You require a plugin to format JSON. To install the plugin do the following steps:

Open notepad++ -> ALT+P -> Plugin Manager -> Selcet JSON Viewer -> Click Install
Restart notepad++
Now you can use shortcut to format json as CTRL + ALT +SHIFT + M or ALT+P -> Plugin Manager -> JSON Viewer -> Format JSON

shell-script headers (#!/bin/sh vs #!/bin/csh)

The #! line tells the kernel (specifically, the implementation of the execve system call) that this program is written in an interpreted language; the absolute pathname that follows identifies the interpreter. Programs compiled to machine code begin with a different byte sequence -- on most modern Unixes, 7f 45 4c 46 (^?ELF) that identifies them as such.

You can put an absolute path to any program you want after the #!, as long as that program is not itself a #! script. The kernel rewrites an invocation of

./script arg1 arg2 arg3 ...

where ./script starts with, say, #! /usr/bin/perl, as if the command line had actually been

/usr/bin/perl ./script arg1 arg2 arg3

Or, as you have seen, you can use #! /bin/sh to write a script intended to be interpreted by sh.

The #! line is only processed if you directly invoke the script (./script on the command line); the file must also be executable (chmod +x script). If you do sh ./script the #! line is not necessary (and will be ignored if present), and the file does not have to be executable. The point of the feature is to allow you to directly invoke interpreted-language programs without having to know what language they are written in. (Do grep '^#!' /usr/bin/* -- you will discover that a great many stock programs are in fact using this feature.)

Here are some rules for using this feature:

The #! must be the very first two bytes in the file. In particular, the file must be in an ASCII-compatible encoding (e.g. UTF-8 will work, but UTF-16 won't) and must not start with a "byte order mark", or the kernel will not recognize it as a #! script.
The path after #! must be an absolute path (starts with /). It cannot contain space, tab, or newline characters.
It is good style, but not required, to put a space between the #! and the /. Do not put more than one space there.
You cannot put shell variables on the #! line, they will not be expanded.
You can put one command-line argument after the absolute path, separated from it by a single space. Like the absolute path, this argument cannot contain space, tab, or newline characters. Sometimes this is necessary to get things to work (#! /usr/bin/awk -f), sometimes it's just useful (#! /usr/bin/perl -Tw). Unfortunately, you cannot put two or more arguments after the absolute path.
Some people will tell you to use #! /usr/bin/env interpreter instead of #! /absolute/path/to/interpreter. This is almost always a mistake. It makes your program's behavior depend on the $PATH variable of the user who invokes the script. And not all systems have env in the first place.
Programs that need setuid or setgid privileges can't use #!; they have to be compiled to machine code. (If you don't know what setuid is, don't worry about this.)

Regarding csh, it relates to sh roughly as Nutrimat Advanced Tea Substitute does to tea. It has (or rather had; modern implementations of sh have caught up) a number of advantages over sh for interactive usage, but using it (or its descendant tcsh) for scripting is almost always a mistake. If you're new to shell scripting in general, I strongly recommend you ignore it and focus on sh. If you are using a csh relative as your login shell, switch to bash or zsh, so that the interactive command language will be the same as the scripting language you're learning.

How to do one-liner if else statement?

As the comments mentioned, Go doesn't support ternary one liners. The shortest form I can think of is this:

var c int
if c = b; a > b {
    c = a
}

But please don't do that, it's not worth it and will only confuse people who read your code.

/** and /* in Java Comments

Java supports two types of comments:

/* multiline comment */ : The compiler ignores everything from /* to */. The comment can span over multiple lines.
// single line : The compiler ignores everything from // to the end of the line.

Some tool such as javadoc use a special multiline comment for their purpose. For example /** doc comment */ is a documentation comment used by javadoc when preparing the automatically generated documentation, but for Java it's a simple multiline comment.

Javascript Object push() function

Javascript programming language supports functional programming paradigm so you can do easily with these codes.

var data = [
    {"Id": "1", "Status": "Valid"},
    {"Id": "2", "Status": "Invalid"}
];
var isValid = function(data){
    return data.Status === "Valid";
};
var valids = data.filter(isValid);

Java foreach loop: for (Integer i : list) { ... }

The API does not support that directly. You can use the for(int i..) loop and count the elements or use subLists(0, size - 1) and handle the last element explicitly:

  if(x.isEmpty()) return;
  int last = x.size() - 1;
  for(Integer i : x.subList(0, last)) out.println(i);
  out.println("last " + x.get(last));

This is only useful if it does not introduce redundancy. It performs better than the counting version (after the subList overhead is amortized). (Just in case you cared after the boxing anyway).

Select a Column in SQL not in Group By

You can do this with PARTITION and RANK:

select * from
(
    select MyPK, fmgcms_cpeclaimid, createdon,  
        Rank() over (Partition BY fmgcms_cpeclaimid order by createdon DESC) as Rank
    from Filteredfmgcms_claimpaymentestimate 
    where createdon < 'reportstartdate' 
) tmp
where Rank = 1

CSS to keep element at "fixed" position on screen

Make sure your content is kept in a div, say divfix.

<div id="divfix">Your Code goes here</div>

CSS :

#divfix {
       bottom: 0;
       right: 0;
       position: fixed;
       z-index: 3000;
}

Hope ,It will help you..

How can I tell if an algorithm is efficient?

Yes you can start with the Wikipedia article explaining the Big O notation, which in a nutshell is a way of describing the "efficiency" (upper bound of complexity) of different type of algorithms. Or you can look at an earlier answer where this is explained in simple english

Laravel Controller Subfolder routing

In my case I had a prefix that had to be added for each route in the group, otherwise response would be that the UserController class was not found.

Route::prefix('/user')->group(function() {
    Route::post('/login', [UserController::class, 'login'])->prefix('/user');
    Route::post('/register', [UserController::class, 'register'])->prefix('/user');
});

How to check if a json key exists?

just before read key check it like before read

JSONObject json_obj=new JSONObject(yourjsonstr);
if(!json_obj.isNull("club"))
{
  //it's contain value to be read operation
}
else
{
  //it's not contain key club or isnull so do this operation here
}

isNull function definition

Returns true if this object has no mapping for name or
if it has a mapping whose value is NULL.

official documentation below link for isNull function

http://developer.android.com/reference/org/json/JSONObject.html#isNull(java.lang.String)

How can I increase the JVM memory?

When starting the JVM, two parameters can be adjusted to suit your memory needs :

-Xms<size>

specifies the initial Java heap size and

-Xmx<size>

the maximum Java heap size.

http://www.rgagnon.com/javadetails/java-0131.html

Installing PDO driver on MySQL Linux server

Basically the answer from Jani Hartikainen is right! I upvoted his answer. What was missing on my system (based on Ubuntu 15.04) was to enable PDO Extension in my php.ini

extension=pdo.so
extension=pdo_mysql.so

restart the webserver (e.g. with "sudo service apache2 restart") -> every fine :-)

To find where your current active php.ini file is located you can use phpinfo() or some other hints from here: https://www.ostraining.com/blog/coding/phpini-file/

How to set default values in Go structs

One problem with option 1 in answer from Victor Zamanian is that if the type isn't exported then users of your package can't declare it as the type for function parameters etc. One way around this would be to export an interface instead of the struct e.g.

package candidate
// Exporting interface instead of struct
type Candidate interface {}
// Struct is not exported
type candidate struct {
    Name string
    Votes uint32 // Defaults to 0
}
// We are forced to call the constructor to get an instance of candidate
func New(name string) Candidate {
    return candidate{name, 0}  // enforce the default value here
}

Which lets us declare function parameter types using the exported Candidate interface. The only disadvantage I can see from this solution is that all our methods need to be declared in the interface definition, but you could argue that that is good practice anyway.

Spring Data JPA Update @Query not updating?

The underlying problem here is the 1st level cache of JPA. From the JPA spec Version 2.2 section 3.1. emphasise is mine:

An EntityManager instance is associated with a persistence context. A persistence context is a set of entity instances in which for any persistent entity identity there is a unique entity instance.

This is important because JPA tracks changes to that entity in order to flush them to the database. As a side effect it also means within a single persistence context an entity gets only loaded once. This why reloading the changed entity doesn't have any effect.

You have a couple of options how to handle this:

Evict the entity from the EntityManager. This may be done by calling EntityManager.detach, annotating the updating method with @Modifying(clearAutomatically = true) which evicts all entities. Make sure changes to these entities get flushed first or you might end up loosing changes.
Use EntityManager.refresh().
Use a different persistence context to load the entity. The easiest way to do this is to do it in a separate transaction. With Spring this can be done by having separate methods annotated with @Transactional on beans called from a bean not annotated with @Transactional. Another way is to use a TransactionTemplate which works especially nicely in tests where it makes transaction boundaries very visible.

Can I pass a JavaScript variable to another browser window?

You can pass variables, and reference to things in the parent window quite easily:

// open an empty sample window:
var win = open("");
win.document.write("<html><body><head></head><input value='Trigger handler in other window!' type='button' id='button'></input></body></html>");

// attach to button in target window, and use a handler in this one:
var button = win.document.getElementById('button');

button.onclick = function() {
     alert("I'm in the first frame!");   
}

How to convert String object to Boolean Object?

To get the boolean value of a String, try this:

public boolean toBoolean(String s) {
    try {
        return Boolean.parseBoolean(s); // Successfully converted String to boolean
    } catch(Exception e) {
        return null; // There was some error, so return null.
    }
}

If there is an error, it will return null. Example:

toBoolean("true"); // Returns true
toBoolean("tr.u;e"); // Returns null

Reading file from Workspace in Jenkins with Groovy script

Although this question is only related to finding directory path ($WORKSPACE) however I had a requirement to read the file from workspace and parse it into JSON object to read sonar issues ( ignore minor/notes issues )

Might help someone, this is how I did it- from readFile

jsonParse(readFile('xyz.json'))

and jsonParse method-

@NonCPS
def jsonParse(text) {
        return new groovy.json.JsonSlurperClassic().parseText(text);
}

This will also require script approval in ManageJenkins-> In-process script approval

How to create a DataTable in C# and how to add rows?

You have to add datarows to your datatable for this.

// Creates a new DataRow with the same schema as the table.
DataRow dr = dt.NewRow();

// Fill the values
dr["Name"] = "Name";
dr["Marks"] = "Marks";

// Add the row to the rows collection
dt.Rows.Add ( dr );

href="javascript:" vs. href="javascript:void(0)"

you could make them all #'s.

You would then need to add return false; to the end of any function that is called onclick of the anchor to not have the page jump up to the top.

Read a javascript cookie by name

One of the shortest ways is this, however as mentioned previously it can return the wrong cookie if there's similar names (MyCookie vs AnotherMyCookie):

var regex = /MyCookie=(.[^;]*)/ig;
var match = regex.exec(document.cookie);
var value = match[1];

I use this in a chrome extension so I know the name I'm setting, and I can make sure there won't be a duplicate, more or less.

Error "The connection to adb is down, and a severe error has occurred."

Try the below steps:

Close Eclipse if running
Go to the Android SDK platform-tools directory in the command prompt
Type adb kill-server (Eclipse should be closed before issuing these commands)
Then type adb start-server
No error message is thrown while starting the ADB server, then ADB is started successfully.
Now you can start Eclipse again.

It worked for me this way.

Restart your phone as well!

How do I set cell value to Date and apply default Excel date format?

This example is for working with .xlsx file types. This example comes from a .jsp page used to create a .xslx spreadsheet.

import org.apache.poi.xssf.usermodel.*; //import needed

XSSFWorkbook  wb = new XSSFWorkbook ();  // Create workbook
XSSFSheet sheet = wb.createSheet();      // Create spreadsheet in workbook
XSSFRow row = sheet.createRow(rowIndex); // Create the row in the spreadsheet


//1. Create the date cell style
XSSFCreationHelper createHelper = wb.getCreationHelper();
XSSFCellStyle cellStyle         = wb.createCellStyle();
cellStyle.setDataFormat(
createHelper.createDataFormat().getFormat("MMMM dd, yyyy")); 

//2. Apply the Date cell style to a cell

//This example sets the first cell in the row using the date cell style
cell = row.createCell(0);
cell.setCellValue(new Date());
cell.setCellStyle(cellStyle);

Can I use a case/switch statement with two variables?

Languages like scala&python give to you very powerful stuff like patternMatching, unfortunately this is still a missing-feature in Java...

but there is a solution (which I don't like in most of the cases), you can do something like this:

final int s1Value = 0;
final int s2Value = 0;
final String s1 = "a";
final String s2 = "g";

switch (s1 + s2 + s1Value + s2Value){
    case "ag00": return true;
    default: return false;
}

Javascript array sort and unique

A way to use a custom sort function

//func has to return 0 in the case in which they are equal
sort_unique = function(arr,func) {
        func = func || function (a, b) {
            return a*1 - b*1;
        };
        arr = arr.sort(func);
        var ret = [arr[0]];
        for (var i = 1; i < arr.length; i++) {
            if (func(arr[i-1],arr[i]) != 0) 
                ret.push(arr[i]);
            }
        }
        return ret;
    }

Example: desc order for an array of objects

MyArray = sort_unique(MyArray , function(a,b){
            return  b.iterator_internal*1 - a.iterator_internal*1;
        });

Binding select element to object in Angular

Also, if nothing else from given solutions doesn't work, check if you imported "FormsModule" inside of "AppModule", that was a key for me.

Use Toast inside Fragment

Unique Approach

(Will work for Dialog, Fragment, Even Util class etc...)

`ApplicationContext.getInstance().toast("I am toast");`

Add below code in Application class accordingly.

public class ApplicationContext extends Application {

private static ApplicationContext instance;

@Override
public void onCreate() {
    super.onCreate();
    instance = this;
}

public static void toast(String message) {
    Toast.makeText(getContext(), message, Toast.LENGTH_SHORT).show();
}
}

Default behavior of "git push" without a branch specified

Rather than using aliases, I prefer creating git-XXX scripts so I can source control them more easily (our devs all have a certain source controlled dir on their path for this type of thing).

This script (called git-setpush) will set the config value for remote.origin.push value to something that will only push the current branch:

#!/bin/bash -eu

CURRENT_BRANCH=$(git branch | grep '^\*' | cut -d" " -f2)
NEW_PUSH_REF=HEAD:refs/for/$CURRENT_BRANCH

echo "setting remote.origin.push to $NEW_PUSH_REF"
git config remote.origin.push $NEW_PUSH_REF

note, as we're using Gerrit, it sets the target to refs/for/XXX to push into a review branch. It also assumes origin is your remote name.

Invoke it after checking out a branch with

git checkout your-branch
git setpush

It could obviously be adapted to also do the checkout, but I like scripts to do one thing and do it well

Adding a new line/break tag in XML

just simply press enter it make a break

<![CDATA[this is
my text.]]>

How do you test to see if a double is equal to NaN?

If your value under test is a Double (not a primitive) and might be null (which is obviously not a number too), then you should use the following term:

(value==null || Double.isNaN(value))

Since isNaN() wants a primitive (rather than boxing any primitive double to a Double), passing a null value (which can't be unboxed to a Double) will result in an exception instead of the expected false.

How to install python-dateutil on Windows?

I followed several suggestions in this list without success. Finally got it installed on Windows using this method: I extracted the zip file and placed the folders under my python27 folder. In a DOS window, I navigated to the installed root folder from extracting the zip file (python-dateutil-2.6.0), then issued this command:

.\python setup.py install

Whammo-bammo it all worked.

jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class

You may find the following windows command line useful in tracking down the offending jar file. it creates an index of all the class files in all the jars in the folder. Execute from within the lib folder of your deployed app, then search the index.txt file for the offending class.

for /r %X in (*.jar) do (echo %X & jar -tf %X) >> index.txt

Viewing local storage contents on IE

Edge (as opposed to IE11) has a better UI for Local storage / Session storage and cookies:

Open Dev tools (F12)
Go to Debugger tab
Click the folder icon to show a list of resources - opens in a separate tab

Detailed 500 error message, ASP + IIS 7.5

Found it.

http://blogs.iis.net/ksingla/archive/2009/02/16/iis-7-5-updates-to-custom-errors-and-compression.aspx

run cmd as administrator, go to your system32\inetsrv folder and execute:

appcmd.exe set config -section:system.webServer/httpErrors -allowAbsolutePathsWhenDelegated:true

Now I can see detailed asp errors .

How to use Bootstrap in an Angular project?

Provided you use the Angular-CLI to generate new projects, there's another way to make bootstrap accessible in Angular 2/4.

Via command line interface navigate to the project folder. Then use npm to install bootstrap:
$ npm install --save bootstrap. The --save option will make bootstrap appear in the dependencies.
Edit the .angular-cli.json file, which configures your project. It's inside the project directory. Add a reference to the "styles" array. The reference has to be the relative path to the bootstrap file downloaded with npm. In my case it's: "../node_modules/bootstrap/dist/css/bootstrap.min.css",

My example .angular-cli.json:

{
  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
  "project": {
    "name": "bootstrap-test"
  },
  "apps": [
    {
      "root": "src",
      "outDir": "dist",
      "assets": [
        "assets",
        "favicon.ico"
      ],
      "index": "index.html",
      "main": "main.ts",
      "polyfills": "polyfills.ts",
      "test": "test.ts",
      "tsconfig": "tsconfig.app.json",
      "testTsconfig": "tsconfig.spec.json",
      "prefix": "app",
      "styles": [
        "../node_modules/bootstrap/dist/css/bootstrap.min.css",
        "styles.css"
      ],
      "scripts": [],
      "environmentSource": "environments/environment.ts",
      "environments": {
        "dev": "environments/environment.ts",
        "prod": "environments/environment.prod.ts"
      }
    }
  ],
  "e2e": {
    "protractor": {
      "config": "./protractor.conf.js"
    }
  },
  "lint": [
    {
      "project": "src/tsconfig.app.json"
    },
    {
      "project": "src/tsconfig.spec.json"
    },
    {
      "project": "e2e/tsconfig.e2e.json"
    }
  ],
  "test": {
    "karma": {
      "config": "./karma.conf.js"
    }
  },
  "defaults": {
    "styleExt": "css",
    "component": {}
  }
}

Now bootstrap should be part of your default settings.

How remove border around image in css?

Here's how I got rid of mine:

.main .row .thumbnail {
    display: inline-block;
    border: 0px;
    background-color: transparent;
}

How to pass a type as a method parameter in Java

Oh, but that's ugly, non-object-oriented code. The moment you see "if/else" and "typeof", you should be thinking polymorphism. This is the wrong way to go. I think generics are your friend here.

How many types do you plan to deal with?

UPDATE:

If you're just talking about String and int, here's one way you might do it. Start with the interface XmlGenerator (enough with "foo"):

package generics;

public interface XmlGenerator<T>
{
   String getXml(T value);
}

And the concrete implementation XmlGeneratorImpl:

    package generics;

public class XmlGeneratorImpl<T> implements XmlGenerator<T>
{
    private Class<T> valueType;
    private static final int DEFAULT_CAPACITY = 1024;

    public static void main(String [] args)
    {
        Integer x = 42;
        String y = "foobar";

        XmlGenerator<Integer> intXmlGenerator = new XmlGeneratorImpl<Integer>(Integer.class);
        XmlGenerator<String> stringXmlGenerator = new XmlGeneratorImpl<String>(String.class);

        System.out.println("integer: " + intXmlGenerator.getXml(x));
        System.out.println("string : " + stringXmlGenerator.getXml(y));
    }

    public XmlGeneratorImpl(Class<T> clazz)
    {
        this.valueType = clazz;
    }

    public String getXml(T value)
    {
        StringBuilder builder = new StringBuilder(DEFAULT_CAPACITY);

        appendTag(builder);
        builder.append(value);
        appendTag(builder, false);

        return builder.toString();
    }

    private void appendTag(StringBuilder builder) { this.appendTag(builder, false); }

    private void appendTag(StringBuilder builder, boolean isClosing)
    {
        String valueTypeName = valueType.getName();
        builder.append("<").append(valueTypeName);
        if (isClosing)
        {
            builder.append("/");
        }
        builder.append(">");
    }
}

If I run this, I get the following result:

integer: <java.lang.Integer>42<java.lang.Integer>
string : <java.lang.String>foobar<java.lang.String>

I don't know if this is what you had in mind.

Removing duplicate rows from table in Oracle

delete from dept
where rowid in (
     select rowid
     from dept
     minus
     select max(rowid)
     from dept
     group by DEPTNO, DNAME, LOC
);

React hooks useState Array

You should not set state (or do anything else with side effects) from within the rendering function. When using hooks, you can use useEffect for this.

The following version works:

import React, { useState, useEffect } from "react";
import ReactDOM from "react-dom";

const StateSelector = () => {
  const initialValue = [
    { id: 0, value: " --- Select a State ---" }];

  const allowedState = [
    { id: 1, value: "Alabama" },
    { id: 2, value: "Georgia" },
    { id: 3, value: "Tennessee" }
  ];

  const [stateOptions, setStateValues] = useState(initialValue);
  // initialValue.push(...allowedState);

  console.log(initialValue.length);
  // ****** BEGINNING OF CHANGE ******
  useEffect(() => {
    // Should not ever set state during rendering, so do this in useEffect instead.
    setStateValues(allowedState);
  }, []);
  // ****** END OF CHANGE ******

  return (<div>
    <label>Select a State:</label>
    <select>
      {stateOptions.map((localState, index) => (
        <option key={localState.id}>{localState.value}</option>
      ))}
    </select>
  </div>);
};

const rootElement = document.getElementById("root");
ReactDOM.render(<StateSelector />, rootElement);

and here it is in a code sandbox.

I'm assuming that you want to eventually load the list of states from some dynamic source (otherwise you could just use allowedState directly without using useState at all). If so, that api call to load the list could also go inside the useEffect block.

Intel HAXM installation error - This computer does not support Intel Virtualization Technology (VT-x)

If none of the answers worked out for you, try this,

Hyper-V might not be disabled If you have windows 10 features such as Device Guard and Credential Guard is enabled, it can prevent Hyper-V from being completely disabled.

The Device Guard and Credential Guard hardware readiness tool released by Microsoft can disable the said Windows 10 features along with Hyper-V:

Download it here, https://www.microsoft.com/en-us/download/details.aspx?id=53337

Download the latest version of the Device Guard and Credential Guard hardware readiness tool. Unzip Open the Command Prompt using Run as administrator @powershell -ExecutionPolicy RemoteSigned -Command "X:\path\to\dgreadiness_v3.6\DG_Readiness_Tool_v3.6.ps1 -Disable" Reboot.

Adding a Time to a DateTime in C#

   DateTime newDateTime = dtReceived.Value.Date.Add(TimeSpan.Parse(dtReceivedTime.Value.ToShortTimeString()));

From Arraylist to Array

assuming v is a ArrayList:

String[] x = (String[]) v.toArray(new String[0]);

Capture screenshot of active window?

If you want to use managed code: This will capture any window via the ProcessId.

I used the following to make the window active.

Microsoft.VisualBasic.Interaction.AppActivate(ProcessId);
Threading.Thread.Sleep(20);

I used the print screen to capture a window.

SendKeys.SendWait("%{PRTSC}");
Threading.Thread.Sleep(40);
IDataObject objData = Clipboard.GetDataObject();

How to rollback or commit a transaction in SQL Server

The good news is a transaction in SQL Server can span multiple batches (each exec is treated as a separate batch.)

You can wrap your EXEC statements in a BEGIN TRANSACTION and COMMIT but you'll need to go a step further and rollback if any errors occur.

Ideally you'd want something like this:

BEGIN TRY
    BEGIN TRANSACTION 
        exec( @sqlHeader)
        exec(@sqlTotals)
        exec(@sqlLine)
    COMMIT
END TRY
BEGIN CATCH

    IF @@TRANCOUNT > 0
        ROLLBACK
END CATCH

The BEGIN TRANSACTION and COMMIT I believe you are already familiar with. The BEGIN TRY and BEGIN CATCH blocks are basically there to catch and handle any errors that occur. If any of your EXEC statements raise an error, the code execution will jump to the CATCH block.

Your existing SQL building code should be outside the transaction (above) as you always want to keep your transactions as short as possible.

How do I split a string so I can access item x?

CREATE FUNCTION [dbo].[fnSplitString] 
( 
    @string NVARCHAR(MAX), 
    @delimiter CHAR(1) 
) 
RETURNS @output TABLE(splitdata NVARCHAR(MAX) 
) 
BEGIN 
    DECLARE @start INT, @end INT 
    SELECT @start = 1, @end = CHARINDEX(@delimiter, @string) 
    WHILE @start < LEN(@string) + 1 BEGIN 
        IF @end = 0  
            SET @end = LEN(@string) + 1

        INSERT INTO @output (splitdata)  
        VALUES(SUBSTRING(@string, @start, @end - @start)) 
        SET @start = @end + 1 
        SET @end = CHARINDEX(@delimiter, @string, @start)

    END 
    RETURN 
END

AND USE IT

select *from dbo.fnSplitString('Querying SQL Server','')

git: fatal: Could not read from remote repository

I meet the problem just now and fix it by: git config user.email "youremail".

update: The root cause maybe my poor network and poor proxy. I still don't know why it happened, but every time has this error, this command works!!!

How to connect to a remote MySQL database with Java?

to access database from remote machine , you need to give grant all privileges to you data base.

run the following script to give permissions: GRANT ALL PRIVILEGES ON . TO user@'%' IDENTIFIED BY 'password';

Passing command line arguments from Maven as properties in pom.xml

Inside pom.xml

<project>

.....

<profiles>
    <profile>
        <id>linux64</id>
        <activation>
            <activeByDefault>true</activeByDefault>
        </activation>
        <properties>
            <build_os>linux</build_os>
            <build_ws>gtk</build_ws>
            <build_arch>x86_64</build_arch>
        </properties>
    </profile>

    <profile>
        <id>win64</id>
        <activation>
            <property>
                <name>env</name>
                <value>win64</value>
            </property>
        </activation>
        <properties>
            <build_os>win32</build_os>
            <build_ws>win32</build_ws>
            <build_arch>x86_64</build_arch>
        </properties>
    </profile>
</profiles>

.....

<plugin>
    <groupId>org.eclipse.tycho</groupId>
    <artifactId>target-platform-configuration</artifactId>
    <version>${tycho.version}</version>
    <configuration>
        <environments>
            <environment>
                <os>${build_os}</os>
                <ws>${build_ws}</ws>
                <arch>${build_arch}</arch>
            </environment>
        </environments>
    </configuration>
</plugin>

.....

In this example when you run the pom without any argument mvn clean install default profile will execute.

When executed with mvn -Denv=win64 clean install

win64 profile will executed.

Please refer http://maven.apache.org/guides/introduction/introduction-to-profiles.html

Apache won't start in wamp

My solution on Windows 10 was just to stop IIS (Internet Information Services).

Check if string begins with something?

You can use string.match() and a regular expression for this too:

if(pathname.match(/^\/sub\/1/)) { // you need to escape the slashes

string.match() will return an array of matching substrings if found, otherwise null.

Mergesort with Python

here is another solution

class MergeSort(object):
    def _merge(self,left, right):
        nl = len(left)
        nr = len(right)
        result = [0]*(nl+nr)
        i=0
        j=0
        for k in range(len(result)):
            if nl>i and nr>j:
                if left[i] <= right[j]:
                    result[k]=left[i]
                    i+=1
                else:
                    result[k]=right[j]
                    j+=1
            elif nl==i:
                result[k] = right[j]
                j+=1
            else: #nr>j:
                result[k] = left[i]
                i+=1
        return result

    def sort(self,arr):
        n = len(arr)
        if n<=1:
            return arr 
        left = self.sort(arr[:n/2])
        right = self.sort(arr[n/2:] )
        return self._merge(left, right)
def main():
    import random
    a= range(100000)
    random.shuffle(a)
    mr_clss = MergeSort()
    result = mr_clss.sort(a)
    #print result

if __name__ == '__main__':
    main()

and here is run time for list with 100000 elements:

real    0m1.073s
user    0m1.053s
sys         0m0.017s

How to change colour of blue highlight on select box dropdown

I believe you are looking for the outline CSS property (in conjunction with active and hover psuedo attributes):

/* turn it off completely */
select:active, select:hover {
  outline: none
}

/* make it red instead (with with same width and style) */
select:active, select:hover {
  outline-color: red
}

Full details of outline, outline-color, outline-style, and outline-width https://developer.mozilla.org/en-US/docs/Web/CSS/outline

Error: "dictionary update sequence element #0 has length 1; 2 is required" on Django 1.4

Here is how I encountered this error in Django and fixed it:

Code with error

urlpatterns = [path('home/', views.home, 'home'),]

Correction

urlpatterns = [path('home/', views.home, name='home'),]

Check if an element contains a class in JavaScript?

A simplified oneliner:¹

function hasClassName(classname,id) {
 return  String ( ( document.getElementById(id)||{} ) .className )
         .split(/\s/)
         .indexOf(classname) >= 0;
}

¹ indexOf for arrays is not supported by IE (ofcourse). There are plenty of monkey patches to be found on the net for that.

How to specify jackson to only use fields - preferably globally

If you want a way to do this globally without worrying about the configuration of your ObjectMapper, you can create your own annotation:

@Target({ElementType.ANNOTATION_TYPE, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@JacksonAnnotationsInside
@JsonAutoDetect(
        getterVisibility = JsonAutoDetect.Visibility.NONE, isGetterVisibility = JsonAutoDetect.Visibility.NONE,
        setterVisibility = JsonAutoDetect.Visibility.NONE, fieldVisibility = JsonAutoDetect.Visibility.NONE,
        creatorVisibility = JsonAutoDetect.Visibility.NONE
)
public @interface JsonExplicit {
}

Now you just have to annotate your classes with @JsonExplicit and you're good to go!

Also make sure to edit the above call to @JsonAutoDetect to make sure you have the values set to what works with your program.

Credit to https://stackoverflow.com/a/13408807 for helping me find out about @JacksonAnnotationsInside

Windows 10 SSH keys

I'm running Microsoft Windows 10 Pro, Version 10.0.17763 Build 17763, and I see my .ssh folder easily at C:\Users\jrosario\.ssh without having to edit permissions or anything (though in File Explorer, I did select "Show hidden files, folders and drives"):

The keys are stored in a text file named known_hosts, which looks roughly like this:

Sum columns with null values in oracle

NVL(value, default) is the function you are looking for.

select type, craft, sum(NVL(regular, 0) + NVL(overtime, 0) ) as total_hours
from hours_t
group by type, craft
order by type, craft

Oracle have 5 NULL-related functions:

NVL
NVL2
COALESCE
NULLIF
LNNVL

NVL:

NVL(expr1, expr2)

NVL lets you replace null (returned as a blank) with a string in the results of a query. If expr1 is null, then NVL returns expr2. If expr1 is not null, then NVL returns expr1.

NVL2 :

NVL2(expr1, expr2, expr3)

NVL2 lets you determine the value returned by a query based on whether a specified expression is null or not null. If expr1 is not null, then NVL2 returns expr2. If expr1 is null, then NVL2 returns expr3.

COALESCE

COALESCE(expr1, expr2, ...)

COALESCE returns the first non-null expr in the expression list. At least one expr must not be the literal NULL. If all occurrences of expr evaluate to null, then the function returns null.

NULLIF

NULLIF(expr1, expr2)

NULLIF compares expr1 and expr2. If they are equal, then the function returns null. If they are not equal, then the function returns expr1. You cannot specify the literal NULL for expr1.

LNNVL

LNNVL(condition)

LNNVL provides a concise way to evaluate a condition when one or both operands of the condition may be null.

More info on Oracle SQL Functions

PHP cURL HTTP CODE return 0

If you connect with the server, then you can get a return code from it, otherwise it will fail and you get a 0. So if you try to connect to "www.google.com/lksdfk" you will get a return code of 400, if you go directly to google.com, you will get 302 (and then 200 if you forward to the next page... well I do because it forwards to google.com.br, so you might not get that), and if you go to "googlecom" you will get a 0 (host no found), so with the last one, there is nobody to send a code back.

Tested using the code below.

<?php

$html_brand = "www.google.com";
$ch = curl_init();

$options = array(
    CURLOPT_URL            => $html_brand,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HEADER         => true,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_ENCODING       => "",
    CURLOPT_AUTOREFERER    => true,
    CURLOPT_CONNECTTIMEOUT => 120,
    CURLOPT_TIMEOUT        => 120,
    CURLOPT_MAXREDIRS      => 10,
);
curl_setopt_array( $ch, $options );
$response = curl_exec($ch); 
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

if ( $httpCode != 200 ){
    echo "Return code is {$httpCode} \n"
        .curl_error($ch);
} else {
    echo "<pre>".htmlspecialchars($response)."</pre>";
}

curl_close($ch);

Truncate with condition

As a response to your question: "i want to reset all the data and keep last 30 days inside the table."

you can create an event. Check https://dev.mysql.com/doc/refman/5.7/en/event-scheduler.html

For example:

CREATE EVENT DeleteExpiredLog
ON SCHEDULE EVERY 1 DAY
DO
DELETE FROM log WHERE date < DATE_SUB(NOW(), INTERVAL 30 DAY);

Will run a daily cleanup in your table, keeping the last 30 days data available

CSS vertically align floating divs

Convert IQueryable<> type object to List<T> type?

Then just Select:

var list = source.Select(s=>new { ID = s.ID, Name = s.Name }).ToList();

(edit) Actually - the names could be inferred in this case, so you could use:

var list = source.Select(s=>new { s.ID, s.Name }).ToList();

which saves a few electrons...

Cannot construct instance of - Jackson

You need to use a concrete class and not an Abstract class while deserializing. if the Abstract class has several implementations then, in that case, you can use it as below-

  @JsonTypeInfo( use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
    @JsonSubTypes({ 
      @Type(value = Bike.class, name = "bike"), 
      @Type(value = Auto.class, name = "auto"), 
      @Type(value = Car.class, name = "car")
    })
    public abstract class Vehicle {
        // fields, constructors, getters, setters
    }

Filtering array of objects with lodash based on property value

With lodash:

const myArr = [ {name: "john", age: 23},
                {name: "john", age: 43},
                {name: "jim", age: 101},
                {name: "bob", age: 67} ];

const johnArr = _.filter(myArr, person => person.name === 'john');
console.log(johnArr)

Vanilla JavaScript:

const myArr = [ {name: "john", age: 23},
                {name: "john", age: 43},
                {name: "jim", age: 101},
                {name: "bob", age: 67} ];

const johnArr = myArr.filter(person => person.name === 'john');
console.log(johnArr);

Generate a random point within a circle (uniformly)

I don't know if this question is still open for a new solution with all the answer already given, but I happened to have faced exactly the same question myself. I tried to "reason" with myself for a solution, and I found one. It might be the same thing as some have already suggested here, but anyway here it is:

in order for two elements of the circle's surface to be equal, assuming equal dr's, we must have dtheta1/dtheta2 = r2/r1. Writing expression of the probability for that element as P(r, theta) = P{ r1< r< r1 + dr, theta1< theta< theta + dtheta1} = f(r,theta)*dr*dtheta1, and setting the two probabilities (for r1 and r2) equal, we arrive to (assuming r and theta are independent) f(r1)/r1 = f(r2)/r2 = constant, which gives f(r) = c*r. And the rest, determining the constant c follows from the condition on f(r) being a PDF.

What do Clustered and Non clustered index actually mean?

Let me offer a textbook definition on "clustering index", which is taken from 15.6.1 from Database Systems: The Complete Book:

We may also speak of clustering indexes, which are indexes on an attribute or attributes such that all of tuples with a fixed value for the search key of this index appear on roughly as few blocks as can hold them.

To understand the definition, let's take a look at Example 15.10 provided by the textbook:

A relation R(a,b) that is sorted on attribute a and stored in that order, packed into blocks, is surely clusterd. An index on a is a clustering index, since for a given a-value a1, all the tuples with that value for a are consecutive. They thus appear packed into blocks, execept possibly for the first and last blocks that contain a-value a1, as suggested in Fig.15.14. However, an index on b is unlikely to be clustering, since the tuples with a fixed b-value will be spread all over the file unless the values of a and b are very closely correlated.

Note that the definition does not enforce the data blocks have to be contiguous on the disk; it only says tuples with the search key are packed into as few data blocks as possible.

A related concept is clustered relation. A relation is "clustered" if its tuples are packed into roughly as few blocks as can possibly hold those tuples. In other words, from a disk block perspective, if it contains tuples from different relations, then those relations cannot be clustered (i.e., there is a more packed way to store such relation by swapping the tuples of that relation from other disk blocks with the tuples the doesn't belong to the relation in the current disk block). Clearly, R(a,b) in example above is clustered.

To connect two concepts together, a clustered relation can have a clustering index and nonclustering index. However, for non-clustered relation, clustering index is not possible unless the index is built on top of the primary key of the relation.

"Cluster" as a word is spammed across all abstraction levels of database storage side (three levels of abstraction: tuples, blocks, file). A concept called "clustered file", which describes whether a file (an abstraction for a group of blocks (one or more disk blocks)) contains tuples from one relation or different relations. It doesn't relate to the clustering index concept as it is on file level.

However, some teaching material likes to define clustering index based on the clustered file definition. Those two types of definitions are the same on clustered relation level, no matter whether they define clustered relation in terms of data disk block or file. From the link in this paragraph,

An index on attribute(s) A on a file is a clustering index when: All tuples with attribute value A = a are stored sequentially (= consecutively) in the data file

Storing tuples consecutively is the same as saying "tuples are packed into roughly as few blocks as can possibly hold those tuples" (with minor difference on one talking about file, the other talking about disk). It's because storing tuple consecutively is the way to achieve "packed into roughly as few blocks as can possibly hold those tuples".

jQuery 1.9 .live() is not a function

A very simple fix that doesn't need to change your code, just add jquery migration script, download here https://github.com/jquery/jquery-migrate/

It supplies jquery deprecated but needed functions like "live", "browser" etc

Hibernate show real SQL

If you can already see the SQL being printed, that means you have the code below in your hibernate.cfg.xml:

<property name="show_sql">true</property>

To print the bind parameters as well, add the following to your log4j.properties file:

log4j.logger.net.sf.hibernate.type=debug

How do I remove the space between inline/inline-block elements?

I'm not pretty sure if you want to make two blue spans without a gap or want to handle other white-space, but if you want to remove the gap:

span {
    display: inline-block;
    width: 100px;
    background: blue;
    font-size: 30px;
    color: white;
    text-align: center;

    float: left;
}

And done.

"sed" command in bash

sed is a stream editor. I would say try man sed.If you didn't find this man page in your system refer this URL:

http://unixhelp.ed.ac.uk/CGI/man-cgi?sed

C#: Printing all properties of an object

Maybe via JavaScriptSerializer.Serialize?

React.js: Wrapping one component into another

In addition to Sophie's answer, I also have found a use in sending in child component types, doing something like this:

var ListView = React.createClass({
    render: function() {
        var items = this.props.data.map(function(item) {
            return this.props.delegate({data:item});
        }.bind(this));
        return <ul>{items}</ul>;
    }
});

var ItemDelegate = React.createClass({
    render: function() {
        return <li>{this.props.data}</li>
    }
});

var Wrapper = React.createClass({    
    render: function() {
        return <ListView delegate={ItemDelegate} data={someListOfData} />
    }
});

Prepend text to beginning of string

If you want to use the version of Javascript called ES 2015 (aka ES6) or later, you can use template strings introduced by ES 2015 and recommended by some guidelines (like Airbnb's style guide):

const after = "test";
const mystr = `This is: ${after}`;

Cannot kill Python script with Ctrl-C

I think it's best to call join() on your threads when you expect them to die. I've taken some liberty with your code to make the loops end (you can add whatever cleanup needs are required to there as well). The variable die is checked for truth on each pass and when it's True then the program exits.

import threading
import time

class MyThread (threading.Thread):
    die = False
    def __init__(self, name):
        threading.Thread.__init__(self)
        self.name = name

    def run (self):
        while not self.die:
            time.sleep(1)
            print (self.name)

    def join(self):
        self.die = True
        super().join()

if __name__ == '__main__':
    f = MyThread('first')
    f.start()
    s = MyThread('second')
    s.start()
    try:
        while True:
            time.sleep(2)
    except KeyboardInterrupt:
        f.join()
        s.join()

Excel VBA - Delete empty rows

How about

sub foo()
  dim r As Range, rows As Long, i As Long
  Set r = ActiveSheet.Range("A1:Z50")
  rows = r.rows.Count
  For i = rows To 1 Step (-1)
    If WorksheetFunction.CountA(r.rows(i)) = 0 Then r.rows(i).Delete
  Next
End Sub

Try this

Option Explicit

Sub Sample()
    Dim i As Long
    Dim DelRange As Range

    On Error GoTo Whoa

    Application.ScreenUpdating = False

    For i = 1 To 50
        If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
            If DelRange Is Nothing Then
                Set DelRange = Range("A" & i & ":" & "Z" & i)
            Else
                Set DelRange = Union(DelRange, Range("A" & i & ":" & "Z" & i))
            End If
        End If
    Next i

    If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
    Application.ScreenUpdating = True

    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

IF you want to delete the entire row then use this code

Option Explicit

Sub Sample()
    Dim i As Long
    Dim DelRange As Range

    On Error GoTo Whoa

    Application.ScreenUpdating = False

    For i = 1 To 50
        If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
            If DelRange Is Nothing Then
                Set DelRange = Rows(i)
            Else
                Set DelRange = Union(DelRange, Rows(i))
            End If
        End If
    Next i

    If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
    Application.ScreenUpdating = True

    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

Array versus linked-list

Only reason to use linked list is that insert the element is easy (removing also).

Disadvatige could be that pointers take a lot of space.

And about that coding is harder: Usually you don't need code linked list (or only once) they are included in STL and it is not so complicated if you still have to do it.

How to print out the method name and line number and conditionally disable NSLog?

For some time I've been using a site of macros adopted from several above. Mine focus on logging in the Console, with the emphasis on controlled & filtered verbosity; if you don't mind a lot of log lines but want to easily switch batches of them on & off, then you might find this useful.

First, I optionally replace NSLog with printf as described by @Rodrigo above

#define NSLOG_DROPCHAFF//comment out to get usual date/time ,etc:2011-11-03 13:43:55.632 myApp[3739:207] Hello Word

#ifdef NSLOG_DROPCHAFF
#define NSLog(FORMAT, ...) printf("%s\n", [[NSString stringWithFormat:FORMAT, ##__VA_ARGS__] UTF8String]);
#endif

Next, I switch logging on or off.

#ifdef DEBUG
#define LOG_CATEGORY_DETAIL// comment out to turn all conditional logging off while keeping other DEBUG features
#endif

In the main block, define various categories corresponding to modules in your app. Also define a logging level above which logging calls won't be called. Then define various flavours of NSLog output

#ifdef LOG_CATEGORY_DETAIL

    //define the categories using bitwise leftshift operators
    #define kLogGCD (1<<0)
    #define kLogCoreCreate (1<<1)
    #define kLogModel (1<<2)
    #define kLogVC (1<<3)
    #define kLogFile (1<<4)
    //etc

    //add the categories that should be logged...
    #define kLOGIFcategory kLogModel+kLogVC+kLogCoreCreate

    //...and the maximum detailLevel to report (use -1 to override the category switch)
    #define kLOGIFdetailLTEQ 4

    // output looks like this:"-[AppDelegate myMethod] log string..."
    #   define myLog(category,detailLevel,format, ...) if(detailLevel<0 || ((category&kLOGIFcategory)&&detailLevel<= kLOGIFdetailLTEQ)) {NSLog((@"%s " format), __PRETTY_FUNCTION__, ##__VA_ARGS__);}

    // output also shows line number:"-[AppDelegate myMethod][l17]  log string..."
    #   define myLogLine(category,detailLevel,format, ...) if(detailLevel<0 || ((category&kLOGIFcategory)&&detailLevel<= kLOGIFdetailLTEQ)) {NSLog((@"%s[l%i] " format), __PRETTY_FUNCTION__,__LINE__ ,##__VA_ARGS__);}

    // output very simple:" log string..."
    #   define myLogSimple(category,detailLevel,format, ...) if(detailLevel<0 || ((category&kLOGIFcategory)&&detailLevel<= kLOGIFdetailLTEQ)) {NSLog((@"" format), ##__VA_ARGS__);}

    //as myLog but only shows method name: "myMethod: log string..."
    // (Doesn't work in C-functions)
    #   define myLog_cmd(category,detailLevel,format,...) if(detailLevel<0 || ((category&kLOGIFcategory)&&detailLevel<= kLOGIFdetailLTEQ)) {NSLog((@"%@: " format), NSStringFromSelector(_cmd), ##__VA_ARGS__);}

    //as myLogLine but only shows method name: "myMethod>l17: log string..."
    #   define myLog_cmdLine(category,detailLevel,format, ...) if(detailLevel<0 || ((category&kLOGIFcategory)&&detailLevel<= kLOGIFdetailLTEQ)) {NSLog((@"%@>l%i: " format), NSStringFromSelector(_cmd),__LINE__ , ##__VA_ARGS__);}

    //or define your own...
   // # define myLogEAGLcontext(category,detailLevel,format, ...) if(detailLevel<0 || ((category&kLOGIFcategory)&&detailLevel<= kLOGIFdetailLTEQ)) {NSLog((@"%s>l%i (ctx:%@)" format), __PRETTY_FUNCTION__,__LINE__ ,[EAGLContext currentContext], ##__VA_ARGS__);}

#else
    #   define myLog_cmd(...)
    #   define myLog_cmdLine(...)
    #   define myLog(...)
    #   define myLogLine(...)
    #   define myLogSimple(...)
    //#   define myLogEAGLcontext(...)
#endif

Thus, with current settings for kLOGIFcategory and kLOGIFdetailLTEQ, a call like

myLogLine(kLogVC, 2, @"%@",self);

will print but this won't

myLogLine(kLogGCD, 2, @"%@",self);//GCD not being printed

nor will

myLogLine(kLogGCD, 12, @"%@",self);//level too high

If you want to override the settings for an individual log call, use a negative level:

myLogLine(kLogGCD, -2, @"%@",self);//now printed even tho' GCD category not active.

I find the few extra characters of typing each line are worth as I can then

Switch an entire category of comment on or off (e.g. only report those calls marked Model)
report on fine detail with higher level numbers or just the most important calls marked with lower numbers

I'm sure many will find this a bit of an overkill, but just in case someone finds it suits their purposes..

Can you do a For Each Row loop using MySQL?

In the link you provided, thats not a loop in sql...

thats a loop in programming language

they are first getting list of all distinct districts, and then for each district executing query again.

How to convert a string or integer to binary in Ruby?

If you're only working with the single digits 0-9, it's likely faster to build a lookup table so you don't have to call the conversion functions every time.

lookup_table = Hash.new
(0..9).each {|x|
    lookup_table[x] = x.to_s(2)
    lookup_table[x.to_s] = x.to_s(2)
}
lookup_table[5]
=> "101"
lookup_table["8"]
=> "1000"

Indexing into this hash table using either the integer or string representation of a number will yield its binary representation as a string.

If you require the binary strings to be a certain number of digits long (keep leading zeroes), then change x.to_s(2) to sprintf "%04b", x (where 4 is the minimum number of digits to use).

Is there an XSL "contains" directive?

Use the standard XPath function contains().

Function: boolean contains(string, string)

The contains function returns true if the first argument string contains the second argument string, and otherwise returns false

Extract specific columns from delimited file using Awk

You can use a for-loop to address a field with $i:

ls -l | awk '{for(i=3 ; i<8 ; i++) {printf("%s\t", $i)} print ""}'

Multidimensional arrays in Swift

Your problem may have been due to a deficiency in an earlier version of Swift or of the Xcode Beta. Working with Xcode Version 6.0 (6A279r) on August 21, 2014, your code works as expected with this output:

column: 0 row: 0 value:1.0
column: 0 row: 1 value:4.0
column: 0 row: 2 value:7.0
column: 1 row: 0 value:2.0
column: 1 row: 1 value:5.0
column: 1 row: 2 value:8.0
column: 2 row: 0 value:3.0
column: 2 row: 1 value:6.0
column: 2 row: 2 value:9.0

I just copied and pasted your code into a Swift playground and defined two constants:

let NumColumns = 3, NumRows = 3

jQuery: Get selected element tag name

You can use the DOM's nodeName property:

$(...)[0].nodeName

Javascript-Setting background image of a DIV via a function and function parameter

If you are looking for a direct approach and using a local File in that case. Try

<div
style={{ background-image: 'url(' + Image + ')', background-size: 'auto' }}
/>

This is the case of JS with inline styling where Image is a local file that you must have imported with a path.

SQL Server - boolean literal?

How to write literal boolean value in SQL Server?
select * from SomeTable where PSEUDO_TRUE

There is no such thing.

You have to compare the value with something using = < > like .... The closest you get a boolean value in SQL Server is the bit. And that is an integer that can have the values null, 0 and 1.

Git: how to reverse-merge a commit?

If you don't want to commit, or want to commit later (commit message will still be prepared for you, which you can also edit):

git revert -n <commit>

Remove from the beginning of std::vector

Given

std::vector<Rule>& topPriorityRules;

The correct way to remove the first element of the referenced vector is

topPriorityRules.erase(topPriorityRules.begin());

which is exactly what you suggested.

Looks like i need to do iterator overloading.

There is no need to overload an iterator in order to erase first element of std::vector.

P.S. Vector (dynamic array) is probably a wrong choice of data structure if you intend to erase from the front.

Convert XML to JSON (and back) using Javascript

Xml-to-json library has methods jsonToXml(json) and xmlToJson(xml).

Remove legend ggplot 2.2

from r cookbook, where bp is your ggplot:

Remove legend for a particular aesthetic (fill):

bp + guides(fill=FALSE)

It can also be done when specifying the scale:

bp + scale_fill_discrete(guide=FALSE)

This removes all legends:

bp + theme(legend.position="none")

Variable name as a string in Javascript

Probably pop would be better than indexing with [0], for safety (variable might be null).

const myFirstName = 'John'
const variableName = Object.keys({myFirstName}).pop();
console.log(`Variable ${variableName} with value '${variable}'`);

// returns "Variable myFirstName with value 'John'"

Change CSS properties on click

In your code you aren't using jquery, so, if you want to use it, yo need something like...

$('#foo').css({'background-color' : 'red', 'color' : 'white', 'font-size' : '44px'});

http://api.jquery.com/css/

Other way, if you are not using jquery, you need to do ...

document.getElementById('foo').style = 'background-color: red; color: white; font-size: 44px';

Shrink to fit content in flexbox, or flex-basis: content workaround?

It turns out that it was shrinking and growing correctly, providing the desired behaviour all along; except that in all current browsers flexbox wasn't accounting for the vertical scrollbar! Which is why the content appears to be getting cut off.

You can see here, which is the original code I was using before I added the fixed widths, that it looks like the column isn't growing to accomodate the text:

http://jsfiddle.net/2w157dyL/1/

However if you make the content in that column wider, you'll see that it always cuts it off by the same amount, which is the width of the scrollbar.

So the fix is very, very simple - add enough right padding to account for the scrollbar:

http://jsfiddle.net/2w157dyL/2/

_x000D_

  main > section {_x000D_
    overflow-y: auto;_x000D_
    padding-right: 2em;_x000D_
  }

_x000D_

It was when I was trying some things suggested by Michael_B (specifically adding a padding buffer) that I discovered this, thanks so much!

Edit: I see that he also posted a fiddle which does the same thing - again, thanks so much for all your help

How can I center text (horizontally and vertically) inside a div block?

This worked for me:

.center-stuff{
    text-align: center;
    vertical-align: middle;
    line-height: 230px; /* This should be the div height */
}

Calculating Page Table Size

In 32 bit virtual address system we can have 2^32 unique address, since the page size given is 4KB = 2^12, we will need (2^32/2^12 = 2^20) entries in the page table, if each entry is 4Bytes then total size of the page table = 4 * 2^20 Bytes = 4MB

How can I store HashMap<String, ArrayList<String>> inside a list?

class Student{
    //instance variable or data members.

    Map<Integer, List<Object>> mapp = new HashMap<Integer, List<Object>>();
    Scanner s1 = new Scanner(System.in);
    String name = s1.nextLine();
    int regno ;
    int mark1;
    int mark2;
    int total;
    List<Object> list = new ArrayList<Object>();
    mapp.put(regno,list); //what wrong in this part?
    list.add(mark1);
    list.add(mark2);**
    //String mark2=mapp.get(regno)[2];
}

break/exit script

You can use the pskill function in the R "tools" package to interrupt the current process and return to the console. Concretely, I have the following function defined in a startup file that I source at the beginning of each script. You can also copy it directly at the start of your code, however. Then insert halt() at any point in your code to stop script execution on the fly. This function works well on GNU/Linux and judging from the R documentation, it should also work on Windows (but I didn't check).

# halt: interrupts the current R process; a short iddle time prevents R from
# outputting further results before the SIGINT (= Ctrl-C) signal is received 
halt <- function(hint = "Process stopped.\n") {
    writeLines(hint)
    require(tools, quietly = TRUE)
    processId <- Sys.getpid() 
    pskill(processId, SIGINT)
    iddleTime <- 1.00
    Sys.sleep(iddleTime)
}

How to hide "Showing 1 of N Entries" with the dataTables.js library

try this for hide

$('#table_id').DataTable({
  "info": false
});

and try this for change label

$('#table_id').DataTable({
 "oLanguage": {
               "sInfo" : "Showing _START_ to _END_ of _TOTAL_ entries",// text you want show for info section
            },

});

Proxy Basic Authentication in C#: HTTP 407 error

try this

        var YourURL = "http://yourUrl/";

         HttpClientHandler handler = new HttpClientHandler() 
         { 
             Proxy = new WebProxy("http://127.0.0.1:8888"), 
             UseProxy = true, 
         }; 

         Console.WriteLine(YourURL); 

         HttpClient client = new HttpClient(handler);

Why can't I check if a 'DateTime' is 'Nothing'?

This is one of the biggest sources of confusion with VB.Net, IMO.

Nothing in VB.Net is the equivalent of default(T) in C#: the default value for the given type.

For value types, this is essentially the equivalent of 'zero': 0 for Integer, False for Boolean, DateTime.MinValue for DateTime, ...
For reference types, it is the null value (a reference that refers to, well, nothing).

The statement d Is Nothing is therefore equivalent to d Is DateTime.MinValue, which obviously does not compile.

Solutions: as others have said

Either use DateTime? (i.e. Nullable(Of DateTime)). This is my preferred solution.
Or use d = DateTime.MinValue or equivalently d = Nothing

In the context of the original code, you could use:

Dim d As DateTime? = Nothing
Dim boolNotSet As Boolean = d.HasValue

A more comprehensive explanation can be found on Anthony D. Green's blog

Preg_match backtrack error

When nesting repetition operators, make absolutely sure that there is only one way to match the same match.

Foreign Key to non-primary key

Necromancing.
I assume when somebody lands here, he needs a foreign key to column in a table that contains non-unique keys.

The problem is, that if you have that problem, the database-schema is denormalized.

You're for example keeping rooms in a table, with a room-uid primary key, a DateFrom and a DateTo field, and another uid, here RM_ApertureID to keep track of the same room, and a soft-delete field, like RM_Status, where 99 means 'deleted', and <> 99 means 'active'.

So when you create the first room, you insert RM_UID and RM_ApertureID as the same value as RM_UID. Then, when you terminate the room to a date, and re-establish it with a new date range, RM_UID is newid(), and the RM_ApertureID from the previous entry becomes the new RM_ApertureID.

So, if that's the case, RM_ApertureID is a non-unique field, and so you can't set a foreign-key in another table.

And there is no way to set a foreign key to a non-unique column/index, e.g. in T_ZO_REM_AP_Raum_Reinigung (WHERE RM_UID is actually RM_ApertureID).
But to prohibit invalid values, you need to set a foreign key, otherwise, data-garbage is the result sooner rather than later...

Now what you can do in this case (short of rewritting the entire application) is inserting a CHECK-constraint, with a scalar function checking the presence of the key:

IF  EXISTS (SELECT * FROM sys.check_constraints WHERE object_id = OBJECT_ID(N'[dbo].[Check_RM_ApertureIDisValid_T_ZO_REM_AP_Raum_Reinigung]') AND parent_object_id = OBJECT_ID(N'[dbo].[T_ZO_REM_AP_Raum_Reinigung]'))
ALTER TABLE dbo.T_ZO_REM_AP_Raum_Reinigung DROP CONSTRAINT [Check_RM_ApertureIDisValid_T_ZO_REM_AP_Raum_Reinigung]
GO


IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[fu_Constaint_ValidRmApertureId]') AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].[fu_Constaint_ValidRmApertureId]
GO




CREATE FUNCTION [dbo].[fu_Constaint_ValidRmApertureId](
     @in_RM_ApertureID uniqueidentifier 
    ,@in_DatumVon AS datetime 
    ,@in_DatumBis AS datetime 
    ,@in_Status AS integer 
) 
    RETURNS bit 
AS 
BEGIN   
    DECLARE @bNoCheckForThisCustomer AS bit 
    DECLARE @bIsInvalidValue AS bit 
    SET @bNoCheckForThisCustomer = 'false' 
    SET @bIsInvalidValue = 'false' 

    IF @in_Status = 99 
        RETURN 'false' 


    IF @in_DatumVon > @in_DatumBis 
    BEGIN 
        RETURN 'true' 
    END 


    IF @bNoCheckForThisCustomer = 'true'
        RETURN @bIsInvalidValue 


    IF NOT EXISTS
    ( 
        SELECT 
             T_Raum.RM_UID 
            ,T_Raum.RM_Status 
            ,T_Raum.RM_DatumVon 
            ,T_Raum.RM_DatumBis 
            ,T_Raum.RM_ApertureID 
        FROM T_Raum 
        WHERE (1=1) 
        AND T_Raum.RM_ApertureID = @in_RM_ApertureID 
        AND @in_DatumVon >= T_Raum.RM_DatumVon 
        AND @in_DatumBis <= T_Raum.RM_DatumBis 
        AND T_Raum.RM_Status <> 99  
    ) 
        SET @bIsInvalidValue = 'true' -- IF ! 

    RETURN @bIsInvalidValue 
END 



GO



IF  EXISTS (SELECT * FROM sys.check_constraints WHERE object_id = OBJECT_ID(N'[dbo].[Check_RM_ApertureIDisValid_T_ZO_REM_AP_Raum_Reinigung]') AND parent_object_id = OBJECT_ID(N'[dbo].[T_ZO_REM_AP_Raum_Reinigung]'))
ALTER TABLE dbo.T_ZO_REM_AP_Raum_Reinigung DROP CONSTRAINT [Check_RM_ApertureIDisValid_T_ZO_REM_AP_Raum_Reinigung]
GO


-- ALTER TABLE dbo.T_AP_Kontakte WITH CHECK ADD CONSTRAINT [Check_RM_ApertureIDisValid_T_ZO_REM_AP_Raum_Reinigung]  
ALTER TABLE dbo.T_ZO_REM_AP_Raum_Reinigung WITH NOCHECK ADD CONSTRAINT [Check_RM_ApertureIDisValid_T_ZO_REM_AP_Raum_Reinigung] 
CHECK 
( 
    NOT 
    ( 
        dbo.fu_Constaint_ValidRmApertureId(ZO_RMREM_RM_UID, ZO_RMREM_GueltigVon, ZO_RMREM_GueltigBis, ZO_RMREM_Status) = 1 
    ) 
) 
GO


IF  EXISTS (SELECT * FROM sys.check_constraints WHERE object_id = OBJECT_ID(N'[dbo].[Check_RM_ApertureIDisValid_T_ZO_REM_AP_Raum_Reinigung]') AND parent_object_id = OBJECT_ID(N'[dbo].[T_ZO_REM_AP_Raum_Reinigung]')) 
ALTER TABLE dbo.T_ZO_REM_AP_Raum_Reinigung CHECK CONSTRAINT [Check_RM_ApertureIDisValid_T_ZO_REM_AP_Raum_Reinigung] 
GO

Substring with reverse index

here is my custom function

function reverse_substring(str,from,to){
  var temp="";
  var i=0;
  var pos = 0;
  var append;      
  for(i=str.length-1;i>=0;i--){
    //alert("inside loop " + str[i]);
    if(pos == from){
         append=true;
    }

    if(pos == to){
         append=false;
         break;
    }
    if(append){
         temp = str[i] + temp;
    }
    pos++;
  }
  alert("bottom loop " + temp);
}

var str = "bala_123";
reverse_substring(str,0,3);

This function works for reverse index.

bodyParser is deprecated express 4

Want zero warnings? Use it like this:

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
  extended: true
}));

Explanation: The default value of the extended option has been deprecated, meaning you need to explicitly pass true or false value.

data type not understood

Try:

mmatrix = np.zeros((nrows, ncols))

Since the shape parameter has to be an int or sequence of ints

http://docs.scipy.org/doc/numpy/reference/generated/numpy.zeros.html

Otherwise you are passing ncols to np.zeros as the dtype.

Serializing an object to JSON

You're looking for JSON.stringify().

How to set JVM parameters for Junit Unit Tests?

According to this support question https://intellij-support.jetbrains.com/hc/en-us/community/posts/206165789-JUnit-default-heap-size-overridden-

the -Xmx argument for an IntelliJ junit test run will come from the maven-surefire-plugin, if it's set.

This pom.xml snippet

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <configuration>
                <argLine>-Xmx1024m</argLine>
            </configuration>
        </plugin>

seems to pass the -Xmx1024 argument to the junit test run, with IntelliJ 2016.2.4.

How to set the color of an icon in Angular Material?

Since for some reason white isn't available for selection, I have found that mat-palette($mat-grey, 50) was close enough to white, for my needs at least.

How do I change button size in Python?

I've always used .place() for my tkinter widgets. place syntax

You can specify the size of it just by changing the keyword arguments!

Of course, you will have to call .place() again if you want to change it.

Works in python 3.8.2, if you're wondering.

In React Native, how do I put a view on top of another view, with part of it lying outside the bounds of the view behind?

The above solutions were not working for me. I solved it by creating a View with the same background colour as the parent and added negative margin to move the image upwards.

<ScrollView style={{ backgroundColor: 'blue' }}>
  <View
    style={{
      width: '95%',
      paddingLeft: '5%',
      marginTop: 80,
      height: 800,
    }}>
    <View style={{ backgroundColor: 'white' }}>

      <Thumbnail square large source={{uri: uri}} style={{ marginTop: -30 }}/>
      <Text>Some Text</Text>
    </View>
  </View>
</ScrollView>

and I got the following result.

Eclipse not recognizing JVM 1.8

JRE is a Run-Time Environment for running Java stuffs on your machine. What Eclipse needs is JDK as a Development Kit.

Install the latest JDK (and not JRE) from http://www.oracle.com/technetwork/pt/java/javase/downloads/jdk8-downloads-2133151.html and you should be good on Mac!

Passing parameters in rails redirect_to

If you are looking for a way to pass additional URL parameters (not controller, action, id, etc), here's a robust method for doing so:

object_path(@object, params: request.query_parameters)

That will pass along utm parameters or any other additional params you don't want to lose.

how to run or install a *.jar file in windows?

If double-clicking on it brings up WinRAR, you need to change the program you are running it with. You can right-click on it and click "Open with". Java should be listed in there.

However, you must first upgrade your Java version to be compatible with that JAR.

convert streamed buffers to utf8-string

Single Buffer

If you have a single Buffer you can use its toString method that will convert all or part of the binary contents to a string using a specific encoding. It defaults to utf8 if you don't provide a parameter, but I've explicitly set the encoding in this example.

var req = http.request(reqOptions, function(res) {
    ...

    res.on('data', function(chunk) {
        var textChunk = chunk.toString('utf8');
        // process utf8 text chunk
    });
});

Streamed Buffers

If you have streamed buffers like in the question above where the first byte of a multi-byte UTF8-character may be contained in the first Buffer (chunk) and the second byte in the second Buffer then you should use a StringDecoder. :

var StringDecoder = require('string_decoder').StringDecoder;

var req = http.request(reqOptions, function(res) {
    ...
    var decoder = new StringDecoder('utf8');

    res.on('data', function(chunk) {
        var textChunk = decoder.write(chunk);
        // process utf8 text chunk
    });
});

This way bytes of incomplete characters are buffered by the StringDecoder until all required bytes were written to the decoder.

What's the best way to send a signal to all members of a process group?

I know that is old, but that is the better solution that i found:

killtree() { 
    for p in $(pstree -p $1 | grep -o "([[:digit:]]*)" |grep -o "[[:digit:]]*" | tac);do
        echo Terminating: $p 
        kill $p
    done
}

jQuery: enabling/disabling datepicker

You can use this code to toggle disabled with jQuery Datepicker and with any other form element also.

_x000D_

/***_x000D_
  *This is the toggle disabled function Start_x000D_
  *_x000D_
  **/_x000D_
(function($) {_x000D_
  $.fn.toggleDisabled = function() {_x000D_
    return this.each(function() {_x000D_
      this.disabled = !this.disabled;_x000D_
      if ($(this).datepicker("option", "disabled")) {_x000D_
        $(this).datepicker("option", "disabled", false);_x000D_
      } else {_x000D_
        $(this).datepicker("option", "disabled", true);_x000D_
      }_x000D_
_x000D_
    });_x000D_
  };_x000D_
})(jQuery);_x000D_
_x000D_
/***_x000D_
  *This is the toggle disabled function Start_x000D_
  *Below is the implementation of the same_x000D_
  **/_x000D_
_x000D_
$(".filtertype").click(function() {_x000D_
  $(".filtertypeinput").toggleDisabled();_x000D_
});_x000D_
_x000D_
/***_x000D_
  *Implementation end_x000D_
  *_x000D_
  **/_x000D_
_x000D_
$("#from").datepicker({_x000D_
  showOn: "button",_x000D_
  buttonImage: "http://jqueryui.com/resources/demos/datepicker/images/calendar.gif",_x000D_
  buttonImageOnly: true,_x000D_
  buttonText: "Select date",_x000D_
  defaultDate: "+1w",_x000D_
  changeMonth: true,_x000D_
  changeYear: true,_x000D_
  numberOfMonths: 1,_x000D_
  onClose: function(selectedDate) {_x000D_
    $("#to").datepicker("option", "minDate", selectedDate);_x000D_
  }_x000D_
});_x000D_
$("#to").datepicker({_x000D_
  showOn: "button",_x000D_
  buttonImage: "http://jqueryui.com/resources/demos/datepicker/images/calendar.gif ",_x000D_
  buttonImageOnly: true,_x000D_
  buttonText: "Select date",_x000D_
  defaultDate: "+1w",_x000D_
  changeMonth: true,_x000D_
  changeYear: true,_x000D_
  numberOfMonths: 1,_x000D_
  onClose: function(selectedDate) {_x000D_
    $("#from").datepicker("option", "maxDate", selectedDate);_x000D_
  }_x000D_
});

_x000D_

<link href="//code.jquery.com/ui/1.11.2/themes/smoothness/jquery-ui.css" rel="stylesheet" />_x000D_
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>_x000D_
<script src="//code.jquery.com/ui/1.11.2/jquery-ui.js"></script>_x000D_
<form>_x000D_
  <table>_x000D_
    <tr>_x000D_
      <th>_x000D_
        <input class="filtertype" type="radio" name="filtertype" checked="checked" value="bydate">_x000D_
      </th>_x000D_
      <th>By Date</th>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td>_x000D_
        <label>Form</label>_x000D_
        <input class="filtertypeinput" id="from">_x000D_
      </td>_x000D_
      <td>_x000D_
        <label>To</label>_x000D_
        <input class="filtertypeinput" id="to">_x000D_
      </td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <th>_x000D_
        <input class="filtertype" type="radio" name="filtertype" value="byyear">_x000D_
      </th>_x000D_
      <th>By Year</th>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td colspan="2">_x000D_
        <select class="filtertypeinput" disabled="disabled">_x000D_
          <option value="">Please select</option>_x000D_
          <option>test 1</option>_x000D_
          <option>test 2</option>_x000D_
        </select>_x000D_
      </td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <th colspan="2">Report</th>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td colspan="2">_x000D_
        <select id="report" name="report">_x000D_
          <option value="">Please Select</option>_x000D_
          <option value="Company">Company</option>_x000D_
          <option value="MyExportAccount">MyExport Account</option>_x000D_
          <option value="Sectors">Sectors</option>_x000D_
          <option value="States">States</option>_x000D_
          <option value="ExportStatus">Export Status</option>_x000D_
          <option value="BusinessType">Business Type</option>_x000D_
          <option value="MobileApp">Mobile App</option>_x000D_
          <option value="Login">Login</option>_x000D_
        </select>_x000D_
      </td>_x000D_
    </tr>_x000D_
  </table>_x000D_
</form>

_x000D_

Combine multiple JavaScript files into one JS file

You can use KjsCompiler: https://github.com/knyga/kjscompiler Cool dependency managment

List of swagger UI alternatives

Yes, there are a few of them.

ReDoc [Article on swagger.io] [GitHub] [demo] - Reinvented OpenAPI/Swagger-generated API Reference Documentation (I'm the author)
OpenAPI GUI [GitHub] [demo] - GUI / visual editor for creating and editing OpenApi / Swagger definitions (has OpenAPI 3 support)
Responsive Fork of SwaggerUI [GitHub] [demo]
SwaggerUI-Angular [GitHub] [demo] - An angularJS implementation of Swagger UI
angular-swagger-ui-material [GitHub] [demo] - Material Design template for angular-swager-ui

Hosted solutions that support swagger:

Apiary - can import from swagger
Readme.io - can import from swagger
Lucybot console - supports swagger natively
Postman - can import from swagger
Stoplight - supports swagger natively - editing and reading

Check the following articles for more details:

Ultimate Guide to 30+ API Documentation Solutions
Turning Contracts into Beautiful Documentation (focused mainly on Swagger)
An evaluation of auto-generated REST API Documentation UIs (focused mainly on Swagger)
Free and Open Source API Documentation Tools

What is android:ems attribute in Edit Text?

Taken from: http://www.w3.org/Style/Examples/007/units:

The em is simply the font size. In an element with a 2in font, 1em thus means 2in. Expressing sizes, such as margins and paddings, in em means they are related to the font size, and if the user has a big font (e.g., on a big screen) or a small font (e.g., on a handheld device), the sizes will be in proportion. Declarations such as 'text-indent: 1.5em' and 'margin: 1em' are extremely common in CSS.

em is basically CSS property for font sizes.

OpenCV NoneType object has no attribute shape

I work with artificially created images,i.e. I create them by myself and then train a neural network on them to perform a certain task. So, I created these images, saved them, but when I tried to open them ( with cv2.imread(...)), I got this error.It turned out that when saving artificially created images you need to add dtype=np.uint8. That resolved the issue for me!

creating batch script to unzip a file without additional zip tools

If you have PowerShell 5.0 or higher (pre-installed with Windows 10 and Windows Server 2016):

powershell Expand-Archive your.zip -DestinationPath your_destination

How to post data to specific URL using WebClient in C#

//Making a POST request using WebClient.
Function()
{    
  WebClient wc = new WebClient();

  var URI = new Uri("http://your_uri_goes_here");

  //If any encoding is needed.
  wc.Headers["Content-Type"] = "application/x-www-form-urlencoded";
  //Or any other encoding type.

  //If any key needed

  wc.Headers["KEY"] = "Your_Key_Goes_Here";

  wc.UploadStringCompleted += 
      new UploadStringCompletedEventHandler(wc_UploadStringCompleted);

  wc.UploadStringAsync(URI,"POST","Data_To_Be_sent");    
}

void wc__UploadStringCompleted(object sender, UploadStringCompletedEventArgs e)    
{  
  try            
  {          
     MessageBox.Show(e.Result); 
     //e.result fetches you the response against your POST request.         
  }
  catch(Exception exc)         
  {             
     MessageBox.Show(exc.ToString());            
  }
}

Setting default permissions for newly created files and sub-directories under a directory in Linux?

It's ugly, but you can use the setfacl command to achieve exactly what you want.

On a Solaris machine, I have a file that contains the acls for users and groups. Unfortunately, you have to list all of the users (at least I couldn't find a way to make this work otherwise):

user::rwx
user:user_a:rwx
user:user_b:rwx
...
group::rwx
mask:rwx
other:r-x
default:user:user_a:rwx
default:user:user_b:rwx
....
default:group::rwx
default:user::rwx
default:mask:rwx
default:other:r-x

Name the file acl.lst and fill in your real user names instead of user_X.

You can now set those acls on your directory by issuing the following command:

setfacl -f acl.lst /your/dir/here

Passing an array of data as an input parameter to an Oracle procedure

If the types of the parameters are all the same (varchar2 for example), you can have a package like this which will do the following:

CREATE OR REPLACE PACKAGE testuser.test_pkg IS

   TYPE assoc_array_varchar2_t IS TABLE OF VARCHAR2(4000) INDEX BY BINARY_INTEGER;

   PROCEDURE your_proc(p_parm IN assoc_array_varchar2_t);

END test_pkg;

CREATE OR REPLACE PACKAGE BODY testuser.test_pkg IS

   PROCEDURE your_proc(p_parm IN assoc_array_varchar2_t) AS
   BEGIN
      FOR i IN p_parm.first .. p_parm.last
      LOOP
         dbms_output.put_line(p_parm(i));
      END LOOP;

   END;

END test_pkg;

Then, to call it you'd need to set up the array and pass it:

DECLARE
  l_array testuser.test_pkg.assoc_array_varchar2_t;
BEGIN
  l_array(0) := 'hello';
  l_array(1) := 'there';  

  testuser.test_pkg.your_proc(l_array);
END;
/

Git Stash vs Shelve in IntelliJ IDEA

git shelve doesn't exist in Git.

Only git stash:

when you want to record the current state of the working directory and the index, but want to go back to a clean working directory.
which saves your local modifications away and reverts the working directory to match the HEAD commit.

You had a 2008 old project git shelve to isolate modifications in a branch, but that wouldn't be very useful nowadays.

As documented in Intellij IDEA shelve dialog, the feature "shelving and unshelving" is not linked to a VCS (Version Control System tool) but to the IDE itself, to temporarily storing pending changes you have not committed yet in changelist.

Note that since Git 2.13 (Q2 2017), you now can stash individual files too.

Receiving login prompt using integrated windows authentication

If your URL has dots in the domain name, IE will treat it like it's an internet address and not local. You have at least two options:

Get an alias to use in the URL to replace server.domain. For example, myapp.
Follow the steps below on your computer.

Go to the site and cancel the login dialog. Let this happen:

In IE’s settings:

what is reverse() in Django

The function supports the dry principle - ensuring that you don't hard code urls throughout your app. A url should be defined in one place, and only one place - your url conf. After that you're really just referencing that info.

Use reverse() to give you the url of a page, given either the path to the view, or the page_name parameter from your url conf. You would use it in cases where it doesn't make sense to do it in the template with {% url 'my-page' %}.

There are lots of possible places you might use this functionality. One place I've found I use it is when redirecting users in a view (often after the successful processing of a form)-

return HttpResponseRedirect(reverse('thanks-we-got-your-form-page'))

You might also use it when writing template tags.

Another time I used reverse() was with model inheritance. I had a ListView on a parent model, but wanted to get from any one of those parent objects to the DetailView of it's associated child object. I attached a get__child_url() function to the parent which identified the existence of a child and returned the url of it's DetailView using reverse().

Use success() or complete() in AJAX call

complete executes after either the success or error callback were executed.

Maybe you should check the second parameter complete offers too. It's a String holding the type of success the ajaxCall had.

The different callbacks are described a little more in detail here jQuery.ajax( options )

I guess you missed the fact that the complete and the success function (I know inconsistent API) get different data passed in. success gets only the data, complete gets the whole XMLHttpRequest object. Of course there is no responseText property on the data string.

So if you replace complete with success you also have to replace data.responseText with data only.

success

The function gets passed two arguments: The data returned from the server, formatted according to the 'dataType' parameter, and a string describing the status.

complete

The function gets passed two arguments: The XMLHttpRequest object and a string describing the type of success of the request.

If you need to have access to the whole XMLHttpRequest object in the success callback I suggest trying this.

var myXHR = $.ajax({
    ...
    success: function(data, status) {
        ...do whatever with myXHR; e.g. myXHR.responseText...
    },
    ...
});

What is class="mb-0" in Bootstrap 4?

Bootstrap has predefined classes that we use for styling. If you are familiar with CSS, you'd know what padding, margin and spacing etc. are.

mb-0 = margin-bottom:0;

OK now moving a little further in knowledge, bootstrap has more classes for margin including:

mt- = margin-top
mb- = margin-bottom
ml- = margin-left
mr- = margin-right
my- = it sets margin-left and margin-right at the same time on y axes
mX- = it sets margin-bottom and margin-top at the same time on X axes

This and much more is explained here https://getbootstrap.com/docs/5.0/utilities/spacing/ The best way to learn is through https://getbootstrap.com site itself. It explains a lot obout its built in classes.

How to insert an item at the beginning of an array in PHP?

Or you can use temporary array and then delete the real one if you want to change it while in cycle:

$array = array(0 => 'a', 1 => 'b', 2 => 'c');
$temp_array = $array[1];

unset($array[1]);
array_unshift($array , $temp_array);

the output will be:

array(0 => 'b', 1 => 'a', 2 => 'c')

and when are doing it while in cycle, you should clean $temp_array after appending item to array.

How to deal with SettingWithCopyWarning in Pandas

I had been getting this issue with .apply() when assigning a new dataframe from a pre-existing dataframe on which i've used the .query() method. For instance:

prop_df = df.query('column == "value"')
prop_df['new_column'] = prop_df.apply(function, axis=1)

Would return this error. The fix that seems to resolve the error in this case is by changing this to:

prop_df = df.copy(deep=True)
prop_df = prop_df.query('column == "value"')
prop_df['new_column'] = prop_df.apply(function, axis=1)

However, this is NOT efficient especially when using large dataframes, due to having to make a new copy.

If you're using the .apply() method in generating a new column and its values, a fix that resolves the error and is more efficient is by adding .reset_index(drop=True):

prop_df = df.query('column == "value"').reset_index(drop=True)
prop_df['new_column'] = prop_df.apply(function, axis=1)

Why is String immutable in Java?

String is immutable for several reasons, here is a summary:

Security: parameters are typically represented as String in network connections, database connection urls, usernames/passwords etc. If it were mutable, these parameters could be easily changed.
Synchronization and concurrency: making String immutable automatically makes them thread safe thereby solving the synchronization issues.
Caching: when compiler optimizes your String objects, it sees that if two objects have same value (a="test", and b="test") and thus you need only one string object (for both a and b, these two will point to the same object).
Class loading: String is used as arguments for class loading. If mutable, it could result in wrong class being loaded (because mutable objects change their state).

That being said, immutability of String only means you cannot change it using its public API. You can in fact bypass the normal API using reflection. See the answer here.

In your example, if String was mutable, then consider the following example:

  String a="stack";
  System.out.println(a);//prints stack
  a.setValue("overflow");
  System.out.println(a);//if mutable it would print overflow

How to deploy a React App on Apache web server

As well described in React's official docs, If you use routers that use the HTML5 pushState history API under the hood, you just need to below content to .htaccess file in public directory of your react-app.

Options -MultiViews
    RewriteEngine On
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteRule ^ index.html [QSA,L]

And if using relative path update the package.json like this:

"homepage": ".",

Note: If you are using react-router@^4, you can root <Link> using the basename prop on any <Router>.

import React from 'react';
import BrowserRouter as Router from 'react-router-dom';
...
<Router basename="/calendar"/>
<Link to="/today"/>

Return Bit Value as 1/0 and NOT True/False in SQL Server

This can be changed to 0/1 through using CASE WHEN like this example:

SELECT 
 CASE WHEN SchemaName.TableName.BitFieldName = 'true' THEN 1 ELSE 0 END AS 'bit Value' 
 FROM SchemaName.TableName

Where to declare variable in react js

Using ES6 syntax in React does not bind this to user-defined functions however it will bind this to the component lifecycle methods.

So the function that you declared will not have the same context as the class and trying to access this will not give you what you are expecting.

For getting the context of class you have to bind the context of class to the function or use arrow functions.

Method 1 to bind the context:

class MyContainer extends Component {

    constructor(props) {
        super(props);
        this.onMove = this.onMove.bind(this);
        this.testVarible= "this is a test";
    }

    onMove() {
        console.log(this.testVarible);
    }
}

Method 2 to bind the context:

class MyContainer extends Component {

    constructor(props) {
        super(props);
        this.testVarible= "this is a test";
    }

    onMove = () => {
        console.log(this.testVarible);
    }
}

Method 2 is my preferred way but you are free to choose your own.

Update: You can also create the properties on class without constructor:

class MyContainer extends Component {

    testVarible= "this is a test";

    onMove = () => {
        console.log(this.testVarible);
    }
}

Note If you want to update the view as well, you should use state and setState method when you set or change the value.

Example:

class MyContainer extends Component {

    state = { testVarible: "this is a test" };

    onMove = () => {
        console.log(this.state.testVarible);
        this.setState({ testVarible: "new value" });
    }
}

Writing a dict to txt file and reading it back?

To store Python objects in files, use the pickle module:

import pickle

a = {
  'a': 1,
  'b': 2
}

with open('file.txt', 'wb') as handle:
  pickle.dump(a, handle)

with open('file.txt', 'rb') as handle:
  b = pickle.loads(handle.read())

print a == b # True

Notice that I never set b = a, but instead pickled a to a file and then unpickled it into b.

As for your error:

self.whip = open('deed.txt', 'r').read()

self.whip was a dictionary object. deed.txt contains text, so when you load the contents of deed.txt into self.whip, self.whip becomes the string representation of itself.

You'd probably want to evaluate the string back into a Python object:

self.whip = eval(open('deed.txt', 'r').read())

Notice how eval sounds like evil. That's intentional. Use the pickle module instead.

Get UTC time in seconds

I bet this is what was intended as a result.

$ date -u --date=@1404372514
Thu Jul  3 07:28:34 UTC 2014

Why can't radio buttons be "readonly"?

I've come up with a javascript-heavy way to achieve a readonly state for check boxes and radio buttons. It is tested against current versions of Firefox, Opera, Safari, Google Chrome, as well as current and previous versions of IE (down to IE7).

Why not simply use the disabled property you ask? When printing the page, disabled input elements come out in a gray color. The customer for which this was implemented wanted all elements to come out the same color.

I'm not sure if I'm allowed to post the source code here, as I developed this while working for a company, but I can surely share the concepts.

With onmousedown events, you can read the selection state before the click action changes it. So you store this information and then restore these states with an onclick event.

<input id="r1" type="radio" name="group1" value="r1" onmousedown="storeSelectedRadiosForThisGroup(this.name);" onclick="setSelectedStateForEachElementOfThisGroup(this.name);" checked="checked">Option 1</input>
<input id="r2" type="radio" name="group1" value="r2" onmousedown="storeSelectedRadiosForThisGroup(this.name);" onclick="setSelectedStateForEachElementOfThisGroup(this.name);">Option 2</input>
<input id="r3" type="radio" name="group1" value="r3" onmousedown="storeSelectedRadiosForThisGroup(this.name);" onclick="setSelectedStateForEachElementOfThisGroup(this.name);">Option 3</input>

<input id="c1" type="checkbox" name="group2" value="c1" onmousedown="storeSelectedRadiosForThisGroup(this.name);" onclick="setSelectedStateForEachElementOfThisGroup(this.name);" checked="checked">Option 1</input>
<input id="c2" type="checkbox" name="group2" value="c2" onmousedown="storeSelectedRadiosForThisGroup(this.name);" onclick="setSelectedStateForEachElementOfThisGroup(this.name);">Option 2</input>
<input id="c3" type="checkbox" name="group2" value="c3" onmousedown="storeSelectedRadiosForThisGroup(this.name);" onclick="setSelectedStateForEachElementOfThisGroup(this.name);" checked="checked">Option 3</input>

The javascript portion of this would then work like this (again only the concepts):

var selectionStore = new Object();  // keep the currently selected items' ids in a store

function storeSelectedRadiosForThisGroup(elementName) {
    // get all the elements for this group
    var radioOrSelectGroup = document.getElementsByName(elementName);

    // iterate over the group to find the selected values and store the selected ids in the selectionStore
    // ((radioOrSelectGroup[i].checked == true) tells you that)
    // remember checkbox groups can have multiple checked items, so you you might need an array for the ids
    ...
}

function setSelectedStateForEachElementOfThisGroup(elementName) {
    // iterate over the group and set the elements checked property to true/false, depending on whether their id is in the selectionStore
    ...

    // make sure you return false here
    return false;
}

You can now enable/disable the radio buttons/checkboxes by changing the onclick and onmousedown properties of the input elements.

Programs & Examples On #Grouped table

Make an image follow mouse pointer

PANIC: Cannot find AVD system path. Please define ANDROID_SDK_ROOT (in windows 10)

What is the 'override' keyword in C++ used for?

pull access denied repository does not exist or may require docker login

What does AND 0xFF do?

Creating a segue programmatically

Reading a resource file from within jar

Create 3D array using Python

ORA-01882: timezone region not found

How to get JavaScript caller function line number? How to get JavaScript caller source URL?

Trim specific character from a string

How can you strip non-ASCII characters from a string? (in C#)

What Scala web-frameworks are available?

How to start up spring-boot application via command line?

Populating a dictionary using for loops (python)

Using getopts to process long and short command line options

How to check whether a str(variable) is empty or not?

How to force input to only allow Alpha Letters?

Table with table-layout: fixed; and how to make one column wider

Joining Multiple Tables - Oracle

How to specify test directory for mocha?

How Spring Security Filter Chain works

Sequence of execution in Spring Security

Implicit type conversion rules in C++ operators

1. Arithmetic Conversions

2 . Integer conversion rules

error: No resource identifier found for attribute 'adSize' in package 'com.google.example' main.xml

Setting HttpContext.Current.Session in a unit test

When should you use constexpr capability in C++11?

How to resize array in C++?

Regular Expression for alphabets with spaces

Change placeholder text

Check if a input box is empty

Python element-wise tuple operations like sum

How Can I Download a File from EC2

How to upload file to server with HTTP POST multipart/form-data?

Can I grep only the first n lines of a file?

How do I check to see if my array includes an object?

How do you get current active/default Environment profile programmatically in Spring?

Returning a value from callback function in Node.js

Use CSS to automatically add 'required field' asterisk to form inputs

Git for beginners: The definitive practical guide

GUIs for git

Git GUI

Features

The endpoint reference (EPR) for the Operation not found is

Correct way of getting Client's IP Addresses from http.Request

Property 'value' does not exist on type 'EventTarget'

How to keep one variable constant with other one changing with row in excel

Autoincrement VersionCode with gradle extra properties

jquery UI dialog: how to initialize without a title bar?

How do you find out the caller function in JavaScript?

Angular JS Uncaught Error: [$injector:modulerr]

jQuery or CSS selector to select all IDs that start with some string

Remove empty lines in a text file via grep

How to read text files with ANSI encoding and non-English letters?

z-index not working with position absolute

What is the difference between smoke testing and sanity testing?

newline character in c# string

How to finish current activity in Android

Listing all permutations of a string/integer

How to make graphics with transparent background in R using ggplot2?

How can I change the user on Git Bash?

Javascript code for showing yesterday's date and todays date

How do I modify fields inside the new PostgreSQL JSON datatype?

NodeJS: How to decode base64 encoded string back to binary?

Java out.println() how is this possible?

converting date time to 24 hour format

Invert match with regexp

Change content of div - jQuery

How to reformat JSON in Notepad++?

shell-script headers (#!/bin/sh vs #!/bin/csh)

How to do one-liner if else statement?

/** and /* in Java Comments

Javascript Object push() function

Java foreach loop: for (Integer i : list) { ... }

Select a Column in SQL not in Group By

CSS to keep element at "fixed" position on screen

How can I tell if an algorithm is efficient?

`ApplicationContext.getInstance().toast("I am toast");`