Programs & Examples On #Static language

Set Colorbar Range in matplotlib

Using vmin and vmax forces the range for the colors. Here's an example:

enter image description here

import matplotlib as m
import matplotlib.pyplot as plt
import numpy as np

cdict = {
  'red'  :  ( (0.0, 0.25, .25), (0.02, .59, .59), (1., 1., 1.)),
  'green':  ( (0.0, 0.0, 0.0), (0.02, .45, .45), (1., .97, .97)),
  'blue' :  ( (0.0, 1.0, 1.0), (0.02, .75, .75), (1., 0.45, 0.45))
}

cm = m.colors.LinearSegmentedColormap('my_colormap', cdict, 1024)

x = np.arange(0, 10, .1)
y = np.arange(0, 10, .1)
X, Y = np.meshgrid(x,y)

data = 2*( np.sin(X) + np.sin(3*Y) )

def do_plot(n, f, title):
    #plt.clf()
    plt.subplot(1, 3, n)
    plt.pcolor(X, Y, f(data), cmap=cm, vmin=-4, vmax=4)
    plt.title(title)
    plt.colorbar()

plt.figure()
do_plot(1, lambda x:x, "all")
do_plot(2, lambda x:np.clip(x, -4, 0), "<0")
do_plot(3, lambda x:np.clip(x, 0, 4), ">0")
plt.show()

EF Code First "Invalid column name 'Discriminator'" but no inheritance

this error happen with me because I did the following

  1. I changed Column name of table in database
  2. (I did not used Update Model from database in Edmx) I Renamed manually Property name to match the change in database schema
  3. I did some refactoring to change name of the property in the class to be the same as database schema and models in Edmx

Although all of this, I got this error

so what to do

  1. I Deleted the model from Edmx
  2. Right Click and Update Model from database

this will regenerate the model, and entity framework will not give you this error

hope this help you

Java says FileNotFoundException but file exists

There are a number situation where a FileNotFoundException may be thrown at runtime.

  1. The named file does not exist. This could be for a number of reasons including:

    • The pathname is simply wrong
    • The pathname looks correct but is actually wrong because it contains non-printing characters (or homoglyphs) that you did not notice
    • The pathname is relative, and it doesn't resolve correctly relative to the actual current directory of the running application. This typically happens because the application's current directory is not what you are expecting or assuming.
    • The path to the file is is broken; e.g. a directory name of the path is incorrect, a symbolic link on the path is broken, or there is a permission problem with one of the path components.
  2. The named file is actually a directory.

  3. The named file cannot be opened for reading for some reason.

The good news that, the problem will inevitably be one of the above. It is just a matter of working out which. Here are some things that you can try:

  • Calling file.exists() will tell you if any file system object exists with the given name / pathname.
  • Calling file.isDirectory() will test if it is a directory.
  • Calling file.canRead() will test if it is a readable file.
  • This line will tell you what the current directory is:

    System.out.println(new File(".").getAbsolutePath());
    
  • This line will print out the pathname in a way that makes it easier to spot things like unexpected leading or trainiong whitespace:

    System.out.println("The path is '" + path + "'");
    

    Look for unexpected spaces, line breaks, etc in the output.


It turns out that your example code has a compilation error.

I ran your code without taking care of the complaint from Netbeans, only to get the following exception message:

Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - unreported exception java.io.FileNotFoundException; must be caught or declared to be thrown

If you change your code to the following, it will fix that problem.

public static void main(String[] args) throws FileNotFoundException {    
    File file = new File("scores.dat");
    System.out.println(file.exists());
    Scanner scan = new Scanner(file);
}

Explanation: the Scanner(File) constructor is declared as throwing the FileNotFoundException exception. (It happens the scanner it cannot open the file.) Now FileNotFoundException is a checked exception. That means that a method in which the exception may be thrown must either catch the exception or declare it in the throws clause. The above fix takes the latter approach.

How to get all of the immediate subdirectories in Python

os.walk is your friend in this situation.

Straight from the documentation:

walk() generates the file names in a directory tree, by walking the tree either top down or bottom up. For each directory in the tree rooted at directory top (including top itself), it yields a 3-tuple (dirpath, dirnames, filenames).

How to properly override clone method?

public class MyObject implements Cloneable, Serializable{   

    @Override
    @SuppressWarnings(value = "unchecked")
    protected MyObject clone(){
        ObjectOutputStream oos = null;
        ObjectInputStream ois = null;
        try {
            ByteArrayOutputStream bOs = new ByteArrayOutputStream();
            oos = new ObjectOutputStream(bOs);
            oos.writeObject(this);
            ois = new ObjectInputStream(new ByteArrayInputStream(bOs.toByteArray()));
            return  (MyObject)ois.readObject();

        } catch (Exception e) {
            //Some seriouse error :< //
            return null;
        }finally {
            if (oos != null)
                try {
                    oos.close();
                } catch (IOException e) {

                }
            if (ois != null)
                try {
                    ois.close();
                } catch (IOException e) {

                }
        }
    }
}

c# - How to get sum of the values from List?

Use Sum()

 List<string> foo = new List<string>();
 foo.Add("1");
 foo.Add("2");
 foo.Add("3");
 foo.Add("4");

 Console.Write(foo.Sum(x => Convert.ToInt32(x)));

Prints:

10

AJAX post error : Refused to set unsafe header "Connection"

Remove these two lines:

xmlHttp.setRequestHeader("Content-length", params.length);
xmlHttp.setRequestHeader("Connection", "close");

XMLHttpRequest isn't allowed to set these headers, they are being set automatically by the browser. The reason is that by manipulating these headers you might be able to trick the server into accepting a second request through the same connection, one that wouldn't go through the usual security checks - that would be a security vulnerability in the browser.

Initialize array of strings

Its fine to just do char **strings;, char **strings = NULL, or char **strings = {NULL}

but to initialize it you'd have to use malloc:

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

int main(){
    // allocate space for 5 pointers to strings
    char **strings = (char**)malloc(5*sizeof(char*));
    int i = 0;
    //allocate space for each string
    // here allocate 50 bytes, which is more than enough for the strings
    for(i = 0; i < 5; i++){
        printf("%d\n", i);
        strings[i] = (char*)malloc(50*sizeof(char));
    }
    //assign them all something
    sprintf(strings[0], "bird goes tweet");
    sprintf(strings[1], "mouse goes squeak");
    sprintf(strings[2], "cow goes moo");
    sprintf(strings[3], "frog goes croak");
    sprintf(strings[4], "what does the fox say?");
    // Print it out
    for(i = 0; i < 5; i++){
        printf("Line #%d(length: %lu): %s\n", i, strlen(strings[i]),strings[i]);
    } 
    //Free each string
    for(i = 0; i < 5; i++){
        free(strings[i]);
    }
    //finally release the first string
    free(strings);
    return 0;
}

How to insert DECIMAL into MySQL database

I noticed something else about your coding.... look

INSERT INTO reports_services (id,title,description,cost) VALUES (0, 'test title', 'test decription ', '3.80')

in your "CREATE TABLE" code you have the id set to "AUTO_INCREMENT" which means it's automatically generating a result for that field.... but in your above code you include it as one of the insertions and in the "VALUES" you have a 0 there... idk if that's your way of telling us you left it blank because it's set to AUTO_INC. or if that's the actual code you have... if it's the code you have not only should you not be trying to send data to a field set to generate it automatically, but the RIGHT WAY to do it WRONG would be

'0',

you put

0,

lol....so that might be causing some of the problem... I also just noticed in the code after "test description" you have a space before the '.... that might be throwing something off too.... idk.. I hope this helps n maybe resolves some other problem you might be pulling your hair out about now.... speaking of which.... I need to figure out my problem before I tear all my hair out..... good luck.. :)

UPDATE.....

I almost forgot... if you have the 0 there to show that it's blank... you could be entering "test title" as the id and "test description" as the title then "3.whatever cents" for the description leaving "cost" empty...... which could be why it maxed out because if I'm not mistaking you have it set to NOT NULL.... and you left it null... so it forced something... maybe.... lol

Vertical Text Direction

To rotate text 90 degrees:

-webkit-transform: rotate(90deg);   
-moz-transform: rotate(90deg);
-ms-transform: rotate(90deg);
-o-transform: rotate(90deg);
transform: rotate(90deg);

Also, it appears that the span tag can't be rotated without being set to display:block.

calculate the mean for each column of a matrix in R

try it ! also can calculate NA's data!

df <- data.frame(a1=1:10, a2=11:20)

df %>% summarise_each(funs( mean( .,na.rm = TRUE)))


# a1   a2
# 5.5 15.5

What are the best use cases for Akka framework

Disclaimer: I am the PO for Akka

Besides offering a concurrency smorgasbord that is much simpler to reason about and to get correct (actors, agents, dataflow concurrency) and with concurrency control in the form of STM.

Here are some use-cases you might consider:

  1. Transaction processing (online gaming, finance, statistics, betting, social media, telecom, ...)
    • scale up, scale out, fault-tolerance / HA
  2. Service backend (any industry, any app)
    • service REST, SOAP, cometd etc
    • act as message hub / integration layer
    • scale up, scale out, fault-tolerance / HA
  3. Snap-in concurrency/parallelism ( any app )
    • Correct
    • Simple to work with and understand
    • Just add the jars to your existing JVM project (use Scala, Java, Groovy or JRuby)
  4. Batch processing ( any industry )
    • Camel integration to hook up with batch data sources
    • Actors divide and conquer the batch workloads
  5. Communications hub ( telecom, web media, mobile media )
    • scale up, scale out, fault-tolerance / HA
  6. Game server (online gaming, betting)
    • scale up, scale out, fault-tolerance / HA
  7. BI/datamining/general purpose crunching
    • scale up, scale out, fault-tolerance / HA
  8. insert other nice use cases here

Which rows are returned when using LIMIT with OFFSET in MySQL?

It will return 18 results starting on record #9 and finishing on record #26.

Start by reading the query from offset. First you offset by 8, which means you skip the first 8 results of the query. Then you limit by 18. Which means you consider records 9, 10, 11, 12, 13, 14, 15, 16....24, 25, 26 which are a total of 18 records.

Check this out.

And also the official documentation.

reducing number of plot ticks

in case somebody still needs it, and since nothing here really worked for me, i came up with a very simple way that keeps the appearance of the generated plot "as is" while fixing the number of ticks to exactly N:

import numpy as np
import matplotlib.pyplot as plt

f, ax = plt.subplots()
ax.plot(range(100))

ymin, ymax = ax.get_ylim()
ax.set_yticks(np.round(np.linspace(ymin, ymax, N), 2))

Select first 10 distinct rows in mysql

Try this SELECT DISTINCT 10 * ...

Check if string contains only whitespace

You want to use the isspace() method

str.isspace()

Return true if there are only whitespace characters in the string and there is at least one character, false otherwise.

That's defined on every string object. Here it is an usage example for your specific use case:

if aStr and (not aStr.isspace()):
    print aStr

Sync data between Android App and webserver

Look at parseplatform.org. it's opensource project.

(As well as you can go for commercial package available at back4app.com.)

It is a very straight forward and user friendly server side database service that gives a great android client side API

Switch statement fall-through...should it be allowed?

I'd love a different syntax for fallbacks in switches, something like, errr..

switch(myParam)
{
  case 0 or 1 or 2:
    // Do something;
    break;
  case 3 or 4:
    // Do something else;
    break;
}

Note: This would already be possible with enums, if you declare all cases on your enum using flags, right? It doesn't sound so bad either; the cases could (should?) very well be part of your enum already.

Maybe this would be a nice case (no pun intended) for a fluent interface using extension methods? Something like, errr...

int value = 10;
value.Switch()
  .Case(() => { /* Do something; */ }, new {0, 1, 2})
  .Case(() => { /* Do something else */ } new {3, 4})
  .Default(() => { /* Do the default case; */ });

Although that's probably even less readable :P

JavaScript set object key by variable

You need to make the object first, then use [] to set it.

var key = "happyCount";
var obj = {};
obj[key] = someValueArray;
myArray.push(obj);

UPDATE 2018:

If you're able to use ES6 and Babel, you can use this new feature:

{
    [yourKeyVariable]: someValueArray,
}  

How to navigate through a vector using iterators? (C++)

Typically, iterators are used to access elements of a container in linear fashion; however, with "random access iterators", it is possible to access any element in the same fashion as operator[].

To access arbitrary elements in a vector vec, you can use the following:

vec.begin()                  // 1st
vec.begin()+1                // 2nd
// ...
vec.begin()+(i-1)            // ith
// ...
vec.begin()+(vec.size()-1)   // last

The following is an example of a typical access pattern (earlier versions of C++):

int sum = 0;
using Iter = std::vector<int>::const_iterator;
for (Iter it = vec.begin(); it!=vec.end(); ++it) {
    sum += *it;
}

The advantage of using iterator is that you can apply the same pattern with other containers:

sum = 0;
for (Iter it = lst.begin(); it!=lst.end(); ++it) {
    sum += *it;
}

For this reason, it is really easy to create template code that will work the same regardless of the container type. Another advantage of iterators is that it doesn't assume the data is resident in memory; for example, one could create a forward iterator that can read data from an input stream, or that simply generates data on the fly (e.g. a range or random number generator).

Another option using std::for_each and lambdas:

sum = 0;
std::for_each(vec.begin(), vec.end(), [&sum](int i) { sum += i; });

Since C++11 you can use auto to avoid specifying a very long, complicated type name of the iterator as seen before (or even more complex):

sum = 0;
for (auto it = vec.begin(); it!=vec.end(); ++it) {
    sum += *it;
}

And, in addition, there is a simpler for-each variant:

sum = 0;
for (auto value : vec) {
    sum += value;
}

And finally there is also std::accumulate where you have to be careful whether you are adding integer or floating point numbers.

Android Gradle Could not reserve enough space for object heap

Solution for Android Studio 2.3.3 on MacOS 10.12.6

Start Android Studios with more heap memory:

export JAVA_OPTS="-Xms6144m -Xmx6144m -XX:NewSize=256m -XX:MaxNewSize=356m -XX:PermSize=256m -XX:MaxPermSize=356m"
open -a /Applications/Android\ Studio.app

How to substring in jquery

Yes you can, although it relies on Javascript's inherent functionality and not the jQuery library.

http://www.w3schools.com/jsref/jsref_substr.asp The substr function will allow you to extract certain parts of the string.

Now, if you're looking for a specific string or character to use to find what part of the string to extract, you can make use of the indexOf function as well. http://www.w3schools.com/jsref/jsref_IndexOf.asp

The question is somewhat vague though; even just link text with 'name' will achieve the desired result. What's the criteria for getting your substring, exactly?

NULL values inside NOT IN clause

Query A is the same as:

select 'true' where 3 = 1 or 3 = 2 or 3 = 3 or 3 = null

Since 3 = 3 is true, you get a result.

Query B is the same as:

select 'true' where 3 <> 1 and 3 <> 2 and 3 <> null

When ansi_nulls is on, 3 <> null is UNKNOWN, so the predicate evaluates to UNKNOWN, and you don't get any rows.

When ansi_nulls is off, 3 <> null is true, so the predicate evaluates to true, and you get a row.

Iteration ng-repeat only X times in AngularJs

Angular comes with a limitTo:limit filter, it support limiting first x items and last x items:

<div ng-repeat="item in items|limitTo:4">{{item}}</div>

Rules for C++ string literals escape character

With the magic of user-defined literals, we have yet another solution to this. C++14 added a std::string literal operator.

using namespace std::string_literals;
auto const x = "\0" "0"s;

Constructs a string of length 2, with a '\0' character (null) followed by a '0' character (the digit zero). I am not sure if it is more or less clear than the initializer_list<char> constructor approach, but it at least gets rid of the ' and , characters.

Pass mouse events through absolutely-positioned element

The reason you are not receiving the event is because the absolutely positioned element is not a child of the element you are wanting to "click" (blue div). The cleanest way I can think of is to put the absolute element as a child of the one you want clicked, but I'm assuming you can't do that or you wouldn't have posted this question here :)

Another option would be to register a click event handler for the absolute element and call the click handler for the blue div, causing them both to flash.

Due to the way events bubble up through the DOM I'm not sure there is a simpler answer for you, but I'm very curious if anyone else has any tricks I don't know about!

Upload DOC or PDF using PHP

You can use

$_FILES['filename']['error'];

If any type of error occurs then it returns 'error' else 1,2,3,4 or 1 if done

1 : if file size is over limit .... You can find other options by googling

Picking a random element from a set

Perl 5

@hash_keys = (keys %hash);
$rand = int(rand(@hash_keys));
print $hash{$hash_keys[$rand]};

Here is one way to do it.

Is it possible to convert char[] to char* in C?

You don't need to declare them as arrays if you want to use use them as pointers. You can simply reference pointers as if they were multi-dimensional arrays. Just create it as a pointer to a pointer and use malloc:

int i;
int M=30, N=25;
int ** buf;
buf = (int**) malloc(M * sizeof(int*));
for(i=0;i<M;i++)
    buf[i] = (int*) malloc(N * sizeof(int));

and then you can reference buf[3][5] or whatever.

Entity Framework 5 Updating a Record

public interface IRepository
{
    void Update<T>(T obj, params Expression<Func<T, object>>[] propertiesToUpdate) where T : class;
}

public class Repository : DbContext, IRepository
{
    public void Update<T>(T obj, params Expression<Func<T, object>>[] propertiesToUpdate) where T : class
    {
        Set<T>().Attach(obj);
        propertiesToUpdate.ToList().ForEach(p => Entry(obj).Property(p).IsModified = true);
        SaveChanges();
    }
}

How to extend / inherit components?

Now that TypeScript 2.2 supports Mixins through Class expressions we have a much better way to express Mixins on Components. Mind you that you can also use Component inheritance since angular 2.3 (discussion) or a custom decorator as discussed in other answers here. However, I think Mixins have some properties that make them preferable for reusing behavior across components:

  • Mixins compose more flexibly, i.e. you can mix and match Mixins on existing components or combine Mixins to form new Components
  • Mixin composition remains easy to understand thanks to its obvious linearization to a class inheritance hierarchy
  • You can more easily avoid issues with decorators and annotations that plague component inheritance (discussion)

I strongly suggest you read the TypeScript 2.2 announcement above to understand how Mixins work. The linked discussions in angular GitHub issues provide additional detail.

You'll need these types:

export type Constructor<T> = new (...args: any[]) => T;

export class MixinRoot {
}

And then you can declare a Mixin like this Destroyable mixin that helps components keep track of subscriptions that need to be disposed in ngOnDestroy:

export function Destroyable<T extends Constructor<{}>>(Base: T) {
  return class Mixin extends Base implements OnDestroy {
    private readonly subscriptions: Subscription[] = [];

    protected registerSubscription(sub: Subscription) {
      this.subscriptions.push(sub);
    }

    public ngOnDestroy() {
      this.subscriptions.forEach(x => x.unsubscribe());
      this.subscriptions.length = 0; // release memory
    }
  };
}

To mixin Destroyable into a Component, you declare your component like this:

export class DashboardComponent extends Destroyable(MixinRoot) 
    implements OnInit, OnDestroy { ... }

Note that MixinRoot is only necessary when you want to extend a Mixin composition. You can easily extend multiple mixins e.g. A extends B(C(D)). This is the obvious linearization of mixins I was talking about above, e.g. you're effectively composing an inheritnace hierarchy A -> B -> C -> D.

In other cases, e.g. when you want to compose Mixins on an existing class, you can apply the Mixin like so:

const MyClassWithMixin = MyMixin(MyClass);

However, I found the first way works best for Components and Directives, as these also need to be decorated with @Component or @Directive anyway.

Function to convert column number to letter?

robertsd's code is elegant, yet to make it future-proof, change the declaration of n to type long

In case you want a formula to avoid macro's, here is something that works up to column 702 inclusive

=IF(A1>26,CHAR(INT((A1-1)/26)+64),"")&CHAR(MOD(A1-1,26)+65)

where A1 is the cell containing the column number to be converted to letters.

How to display Woocommerce Category image?

You may also used foreach loop for display category image and etc from parent category given by parent id.

for example, i am giving 74 id of parent category, then i will display the image from child category and its slug also.

**<?php
$catTerms = get_terms('product_cat', array('hide_empty' => 0, 'orderby' => 'ASC', 'child_of'=>'74'));
foreach($catTerms as $catTerm) : ?>
<?php $thumbnail_id = get_woocommerce_term_meta( $catTerm->term_id, 'thumbnail_id', true ); 

// get the image URL
$image = wp_get_attachment_url( $thumbnail_id );  ?>
<li><img src="<?php echo $image; ?>" width="152" height="245"/><span><?php echo $catTerm->name; ?></span></li>
<?php endforeach; ?>** 

How to read XML using XPath in Java

You need something along the lines of this:

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(<uri_as_string>);
XPathFactory xPathfactory = XPathFactory.newInstance();
XPath xpath = xPathfactory.newXPath();
XPathExpression expr = xpath.compile(<xpath_expression>);

Then you call expr.evaluate() passing in the document defined in that code and the return type you are expecting, and cast the result to the object type of the result.

If you need help with a specific XPath expressions, you should probably ask it as separate questions (unless that was your question in the first place here - I understood your question to be how to use the API in Java).

Edit: (Response to comment): This XPath expression will get you the text of the first URL element under PowerBuilder:

/howto/topic[@name='PowerBuilder']/url/text()

This will get you the second:

/howto/topic[@name='PowerBuilder']/url[2]/text()

You get that with this code:

expr.evaluate(doc, XPathConstants.STRING);

If you don't know how many URLs are in a given node, then you should rather do something like this:

XPathExpression expr = xpath.compile("/howto/topic[@name='PowerBuilder']/url");
NodeList nl = (NodeList) expr.evaluate(doc, XPathConstants.NODESET);

And then loop over the NodeList.

urllib and "SSL: CERTIFICATE_VERIFY_FAILED" Error

Python 2.7.12 (default, Jul 29 2016, 15:26:22) fixed the mentioned issue. This information might help someone else.

Class JavaLaunchHelper is implemented in two places

This happened to me when I installed Intellij IDEA 2017, go to menu Preferences -> Build, Execution, Deployment -> Debugger and disable the option: "Force Classic VM for JDK 1.3.x and earlier". This works to me.

Can't type in React input text field

defaultValue instead of value worked for me .

How can I protect my .NET assemblies from decompilation?

I know you don't want to obfuscate, but maybe you should check out dotfuscator, it will take your compiled assemblies and obfuscate them for you. I think it can even encrypt them.

How to update ruby on linux (ubuntu)?

There's really no reason to remove ruby1-8, unless someone else knows better. Execute the commands below to install 1.9 and then link ruby to point to the new version.

sudo apt-get install ruby1-9 rubygems1-9
sudo ln -sf /usr/bin/ruby1-9 /usr/bin/ruby

Interesting 'takes exactly 1 argument (2 given)' Python error

Am I getting it because the act of calling it via e.extractAll("th") also passes in self as an argument?

Yes, that's precisely it. If you like, the first parameter is the object name, e that you are calling it with.

And if so, by removing the self in the call, would I be making it some kind of class method that can be called like Extractor.extractAll("th")?

Not quite. A classmethod needs the @classmethod decorator, and that accepts the class as the first paramater (usually referenced as cls). The only sort of method that is given no automatic parameter at all is known as a staticmethod, and that again needs a decorator (unsurprisingly, it's @staticmethod). A classmethod is used when it's an operation that needs to refer to the class itself: perhaps instantiating objects of the class; a staticmethod is used when the code belongs in the class logically, but requires no access to class or instance.

But yes, both staticmethods and classmethods can be called by referencing the classname as you describe: Extractor.extractAll("th").

Setting timezone in Python

You can use pytz as well..

import datetime
import pytz
def utcnow():
    return datetime.datetime.now(tz=pytz.utc)
utcnow()
   datetime.datetime(2020, 8, 15, 14, 45, 19, 182703, tzinfo=<UTC>)
utcnow().isoformat()

'

2020-08-15T14:45:21.982600+00:00'

mysql delete under safe mode

You can trick MySQL into thinking you are actually specifying a primary key column. This allows you to "override" safe mode.

Assuming you have a table with an auto-incrementing numeric primary key, you could do the following:

DELETE FROM tbl WHERE id <> 0

Maven build debug in Eclipse

if you are using Maven 2.0.8+, then it will be very simple, run mvndebug from the console, and connect to it via Remote Debug Java Application with port 8000.

Python + Django page redirect

If you want to redirect a whole subfolder, the url argument in RedirectView is actually interpolated, so you can do something like this in urls.py:

from django.conf.urls.defaults import url
from django.views.generic import RedirectView

urlpatterns = [
    url(r'^old/(?P<path>.*)$', RedirectView.as_view(url='/new_path/%(path)s')),
]

The ?P<path> you capture will be fed into RedirectView. This captured variable will then be replaced in the url argument you gave, giving us /new_path/yay/mypath if your original path was /old/yay/mypath.

You can also do ….as_view(url='…', query_string=True) if you want to copy the query string over as well.

How to disable 'X-Frame-Options' response header in Spring Security?

If you are using Spring Security's Java configuration, all of the default security headers are added by default. They can be disabled using the Java configuration below:

@EnableWebSecurity
@Configuration
public class WebSecurityConfig extends
   WebSecurityConfigurerAdapter {

  @Override
  protected void configure(HttpSecurity http) throws Exception {
    http
      .headers().disable()
      ...;
  }
}

How do I delete an entity from symfony2

Symfony is smart and knows how to make the find() by itself :

public function deleteGuestAction(Guest $guest)
{
    if (!$guest) {
        throw $this->createNotFoundException('No guest found');
    }

    $em = $this->getDoctrine()->getEntityManager();
    $em->remove($guest);
    $em->flush();

    return $this->redirect($this->generateUrl('GuestBundle:Page:viewGuests.html.twig'));
}

To send the id in your controller, use {{ path('your_route', {'id': guest.id}) }}

How can I URL encode a string in Excel VBA?

(Bump on an old thread). Just for kicks, here's a version that uses pointers to assemble the result string. It's about 2x - 4x as fast as the faster second version in the accepted answer.

Public Declare PtrSafe Sub Mem_Copy Lib "kernel32" _
    Alias "RtlMoveMemory" (ByRef Destination As Any, ByRef Source As Any, ByVal Length As Long)

Public Declare PtrSafe Sub Mem_Read2 Lib "msvbvm60" _
    Alias "GetMem2" (ByRef Source As Any, ByRef Destination As Any)

Public Function URLEncodePart(ByRef RawURL As String) As String

    Dim pChar As LongPtr, iChar As Integer, i As Long
    Dim strHex As String, pHex As LongPtr
    Dim strOut As String, pOut As LongPtr
    Dim pOutStart As LongPtr, pLo As LongPtr, pHi As LongPtr
    Dim lngLength As Long
    Dim cpyLength As Long
    Dim iStart As Long

    pChar = StrPtr(RawURL)
    If pChar = 0 Then Exit Function

    lngLength = Len(RawURL)
    strOut = Space(lngLength * 3)
    pOut = StrPtr(strOut)
    pOutStart = pOut
    strHex = "0123456789ABCDEF"
    pHex = StrPtr(strHex)

    iStart = 1
    For i = 1 To lngLength
        Mem_Read2 ByVal pChar, iChar
        Select Case iChar
            Case 97 To 122, 65 To 90, 48 To 57, 45, 46, 95, 126
              ' Ok
            Case Else
                If iStart < i Then
                    cpyLength = (i - iStart) * 2
                    Mem_Copy ByVal pOut, ByVal pChar - cpyLength, cpyLength
                    pOut = pOut + cpyLength
                End If

                pHi = pHex + ((iChar And &HF0) / 8)
                pLo = pHex + 2 * (iChar And &HF)

                Mem_Read2 37, ByVal pOut
                Mem_Read2 ByVal pHi, ByVal pOut + 2
                Mem_Read2 ByVal pLo, ByVal pOut + 4
                pOut = pOut + 6

                iStart = i + 1
        End Select
        pChar = pChar + 2
    Next

    If iStart <= lngLength Then
        cpyLength = (lngLength - iStart + 1) * 2
        Mem_Copy ByVal pOut, ByVal pChar - cpyLength, cpyLength
        pOut = pOut + cpyLength
    End If

    URLEncodePart = Left$(strOut, (pOut - pOutStart) / 2)

End Function

What's the best way to use R scripts on the command line (terminal)?

The following works for me using MSYS bash on Windows - I don't have R on my Linux box so can't try it there. You need two files - the first one called runr executes R with a file parameter

# this is runr
# following is path to R on my Windows machine
# plus any R params you need
c:/r/bin/r --file=$1

You need to make this executable with chmod +x runr.

Then in your script file:

#!runr
# some R commands
x = 1
x

Note the #! runr line may need to include the full path to runr, depending on how you are using the command, how your PATH variable is set etc.

Not pretty, but it does seem to work!

adding child nodes in treeview

void treeView(string [] LineString)
    {
        int line = LineString.Length;
        string AssmMark = "";
        string PartMark = "";
        TreeNode aNode;
        TreeNode pNode;
        for ( int i=0 ; i<line ; i++){
            string sLine = LineString[i];
            if ( sLine.StartsWith("ASSEMBLY:") ){
                sLine  = sLine.Replace("ASSEMBLY:","");
                string[] aData = sLine.Split(new char[] {','});
                AssmMark  = aData[0].Trim();
                //TreeNode aNode;
                //aNode = new TreeNode(AssmMark);
                treeView1.Nodes.Add(AssmMark,AssmMark);
            }
            if( sLine.Trim().StartsWith("PART:") ){
                sLine  = sLine.Replace("PART:","");
                string[] pData = sLine.Split(new char[] {','});
                PartMark = pData[0].Trim();
                pNode = new TreeNode(PartMark);
                treeView1.Nodes[AssmMark].Nodes.Add(pNode);
            }
        }

Vue v-on:click does not work on component

As mentioned by Chris Fritz (Vue.js Core Team Emeriti) in VueCONF US 2019

if we had Kia enter .native and then the root element of the base input changed from an input to a label suddenly this component is broken and it's not obvious and in fact, you might not even catch it right away unless you have a really good test. Instead by avoiding the use of the .native modifier which I currently consider an anti-pattern will be removed in Vue 3 you'll be able to explicitly define that the parent might care about which element listeners are added to...

With Vue 2

Using $listeners:

So, if you are using Vue 2 a better option to resolve this issue would be to use a fully transparent wrapper logic. For this Vue provides a $listeners property containing an object of listeners being used on the component. For example:

{
  focus: function (event) { /* ... */ }
  input: function (value) { /* ... */ },
}

and then we just need to add v-on="$listeners" to the test component like:

Test.vue (child component)

<template>
  <div v-on="$listeners">
    click here
  </div>
</template>

Now the <test> component is a fully transparent wrapper, meaning it can be used exactly like a normal <div> element: all the listeners will work, without the .native modifier.

Demo:

_x000D_
_x000D_
Vue.component('test', {_x000D_
  template: `_x000D_
    <div class="child" v-on="$listeners">_x000D_
      Click here_x000D_
    </div>`_x000D_
})_x000D_
_x000D_
new Vue({_x000D_
  el: "#myApp",_x000D_
  data: {},_x000D_
  methods: {_x000D_
    testFunction: function(event) {_x000D_
      console.log('test clicked')_x000D_
    }_x000D_
  }_x000D_
})
_x000D_
div.child{border:5px dotted orange; padding:20px;}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.min.js"></script>_x000D_
<div id="myApp">_x000D_
  <test @click="testFunction"></test>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Using $emit method:

We can also use $emit method for this purpose, which helps us to listen to child components events in parent component. For this, we first need to emit a custom event from child component like:

Test.vue (child component)

<test @click="$emit('my-event')"></test>

Important: Always use kebab-case for event names. For more information and demo regading this point please check out this answer: VueJS passing computed value from component to parent.

Now, we just need to listen to this emitted custom event in parent component like:

App.vue

<test @my-event="testFunction"></test>

So, basically instead of v-on:click or the shorthand @click we will simply use v-on:my-event or just @my-event.

Demo:

_x000D_
_x000D_
Vue.component('test', {_x000D_
  template: `_x000D_
    <div class="child" @click="$emit('my-event')">_x000D_
      Click here_x000D_
    </div>`_x000D_
})_x000D_
_x000D_
new Vue({_x000D_
  el: "#myApp",_x000D_
  data: {},_x000D_
  methods: {_x000D_
    testFunction: function(event) {_x000D_
      console.log('test clicked')_x000D_
    }_x000D_
  }_x000D_
})
_x000D_
div.child{border:5px dotted orange; padding:20px;}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.min.js"></script>_x000D_
<div id="myApp">_x000D_
  <test @my-event="testFunction"></test>_x000D_
</div>
_x000D_
_x000D_
_x000D_


With Vue 3

Using v-bind="$attrs":

Vue 3 is going to make our life much easier in many ways. One of the examples for it is that it will help us to create a simpler transparent wrapper with very less config by just using v-bind="$attrs". By using this on child components not only our listener will work directly from the parent but also any other attribute will also work just like it a normal <div> only.

So, with respect to this question, we will not need to update anything in Vue 3 and your code will still work fine as <div> is the root element here and it will automatically listen to all child events.

Demo #1:

_x000D_
_x000D_
const { createApp } = Vue;_x000D_
_x000D_
const Test = {_x000D_
  template: `_x000D_
    <div class="child">_x000D_
      Click here_x000D_
    </div>`_x000D_
};_x000D_
_x000D_
const App = {_x000D_
  components: { Test },_x000D_
  setup() {_x000D_
    const testFunction = event => {_x000D_
      console.log("test clicked");_x000D_
    };_x000D_
    return { testFunction };_x000D_
  }_x000D_
};_x000D_
_x000D_
createApp(App).mount("#myApp");
_x000D_
div.child{border:5px dotted orange; padding:20px;}
_x000D_
<script src="//unpkg.com/vue@next"></script>_x000D_
<div id="myApp">_x000D_
  <test v-on:click="testFunction"></test>_x000D_
</div>
_x000D_
_x000D_
_x000D_

But for complex components with nested elements where we need to apply attributes and events to main <input /> instead of the parent label we can simply use v-bind="$attrs"

Demo #2:

_x000D_
_x000D_
const { createApp } = Vue;_x000D_
_x000D_
const BaseInput = {_x000D_
  props: ['label', 'value'],_x000D_
  template: `_x000D_
    <label>_x000D_
      {{ label }}_x000D_
      <input v-bind="$attrs">_x000D_
    </label>`_x000D_
};_x000D_
_x000D_
const App = {_x000D_
  components: { BaseInput },_x000D_
  setup() {_x000D_
    const search = event => {_x000D_
      console.clear();_x000D_
      console.log("Searching...", event.target.value);_x000D_
    };_x000D_
    return { search };_x000D_
  }_x000D_
};_x000D_
_x000D_
createApp(App).mount("#myApp");
_x000D_
input{padding:8px;}
_x000D_
<script src="//unpkg.com/vue@next"></script>_x000D_
<div id="myApp">_x000D_
  <base-input _x000D_
    label="Search: "_x000D_
    placeholder="Search"_x000D_
    @keyup="search">_x000D_
  </base-input><br/>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Failed to connect to camera service

running your code hundred times may affect the camera to function wrongly.Your activity may be performing correctly but system could not buy it.so camera forces stop. One main tip all missed is rebooting your phone and not only eclipse..It worked for me..

Check if certain value is contained in a dataframe column in pandas

You can simply use this:

'07311954' in df.date.values which returns True or False


Here is the further explanation:

In pandas, using in check directly with DataFrame and Series (e.g. val in df or val in series ) will check whether the val is contained in the Index.

BUT you can still use in check for their values too (instead of Index)! Just using val in df.col_name.values or val in series.values. In this way, you are actually checking the val with a Numpy array.

And .isin(vals) is the other way around, it checks whether the DataFrame/Series values are in the vals. Here vals must be set or list-like. So this is not the natural way to go for the question.

How do I create a comma delimited string from an ArrayList?

Something like:

String.Join(",", myArrayList.toArray(string.GetType()) );

Which basically loops ya know...

EDIT

how about:

string.Join(",", Array.ConvertAll<object, string>(a.ToArray(), Convert.ToString));

HTTP Basic Authentication - what's the expected web browser experience?

You can use Postman a plugin for chrome. It gives the ability to choose the authentication type you need for each of the requests. In that menu you can configure user and password. Postman will automatically translate the config to a authentication header that will be sent with your request.

GenyMotion Unable to start the Genymotion virtual device

I was struggling with this for a while and finally found a solution on Windows 10.

Steps:

Network and Sharing Center > Change Adapter Settings > Right Click on VirtualBox Host-Only Network ( If you have multiple do the following to all of them ) > Properties > Check the VirtualBox NDUS6 Bridged Networking Driver

Truncating all tables in a Postgres database

FrustratedWithFormsDesigner is correct, PL/pgSQL can do this. Here's the script:

CREATE OR REPLACE FUNCTION truncate_tables(username IN VARCHAR) RETURNS void AS $$
DECLARE
    statements CURSOR FOR
        SELECT tablename FROM pg_tables
        WHERE tableowner = username AND schemaname = 'public';
BEGIN
    FOR stmt IN statements LOOP
        EXECUTE 'TRUNCATE TABLE ' || quote_ident(stmt.tablename) || ' CASCADE;';
    END LOOP;
END;
$$ LANGUAGE plpgsql;

This creates a stored function (you need to do this just once) which you can afterwards use like this:

SELECT truncate_tables('MYUSER');

Delete specific line from a text file?

Are you on a Unix operating system?

You can do this with the "sed" stream editor. Read the man page for "sed"

Best way to initialize (empty) array in PHP

In ECMAScript implementations (for instance, ActionScript or JavaScript), Array() is a constructor function and [] is part of the array literal grammar. Both are optimized and executed in completely different ways, with the literal grammar not being dogged by the overhead of calling a function.

PHP, on the other hand, has language constructs that may look like functions but aren't treated as such. Even with PHP 5.4, which supports [] as an alternative, there is no difference in overhead because, as far as the compiler/parser is concerned, they are completely synonymous.

// Before 5.4, you could only write
$array = array(
    "foo" => "bar",
    "bar" => "foo",
);

// As of PHP 5.4, the following is synonymous with the above
$array = [
    "foo" => "bar",
    "bar" => "foo",
];

If you need to support older versions of PHP, use the former syntax. There's also an argument for readability but, being a long-time JS developer, the latter seems rather natural to me. I actually made the mistake of trying to initialise arrays using [] when I was first learning PHP.

This change to the language was originally proposed and rejected due to a majority vote against by core developers with the following reason:

This patch will not be accepted because slight majority of the core developers voted against. Though if you take a accumulated mean between core developers and userland votes seems to show the opposite it would be irresponsible to submit a patch witch is not supported or maintained in the long run.

However, it appears there was a change of heart leading up to 5.4, perhaps influenced by the implementations of support for popular databases like MongoDB (which use ECMAScript syntax).

Show/hide widgets in Flutter programmatically

UPDATE: Since this answer was written, Visibility was introduced and provides the best solution to this problem.


You can use Opacity with an opacity: of 0.0 to draw make an element hidden but still occupy space.

To make it not occupy space, replace it with an empty Container().

EDIT: To wrap it in an Opacity object, do the following:

            new Opacity(opacity: 0.0, child: new Padding(
              padding: const EdgeInsets.only(
                left: 16.0,
              ),
              child: new Icon(pencil, color: CupertinoColors.activeBlue),
            ))

Google Developers quick tutorial on Opacity: https://youtu.be/9hltevOHQBw

How to execute a java .class from the command line

You need to specify the classpath. This should do it:

java -cp . Echo "hello"

This tells java to use . (the current directory) as its classpath, i.e. the place where it looks for classes. Note than when you use packages, the classpath has to contain the root directory, not the package subdirectories. e.g. if your class is my.package.Echo and the .class file is bin/my/package/Echo.class, the correct classpath directory is bin.

Font-awesome, input type 'submit'

You can use font awesome utf cheatsheet

<input type="submit" class="btn btn-success" value="&#xf011; Login"/>

here is the link for the cheatsheet http://fortawesome.github.io/Font-Awesome/cheatsheet/

Allow all remote connections, MySQL

Also you need to disable below line in configuration file: bind-address = 127.0.0.1

Simple 'if' or logic statement in Python

Here's a Boolean thing:

if (not suffix == "flac" )  or (not suffix == "cue" ):   # WRONG! FAILS
    print  filename + ' is not a flac or cue file'

but

if not (suffix == "flac"  or suffix == "cue" ):     # CORRECT!
       print  filename + ' is not a flac or cue file'

(not a) or (not b) == not ( a and b ) , is false only if a and b are both true

not (a or b) is true only if a and be are both false.

Is there a RegExp.escape function in JavaScript?

Rather than only escaping characters which will cause issues in your regular expression (e.g.: a blacklist), consider using a whitelist instead. This way each character is considered tainted unless it matches.

For this example, assume the following expression:

RegExp.escape('be || ! be');

This whitelists letters, number and spaces:

RegExp.escape = function (string) {
    return string.replace(/([^\w\d\s])/gi, '\\$1');
}

Returns:

"be \|\| \! be"

This may escape characters which do not need to be escaped, but this doesn't hinder your expression (maybe some minor time penalties - but it's worth it for safety).

how to open a jar file in Eclipse

use java decompiler. http://jd.benow.ca/. you can open the jar files.

Thanks, Manirathinam.

How to write ternary operator condition in jQuery?

The Ternary operator is just written as a boolean expression followed by a questionmark and then two further expressions separated by a colon.

The first thing that I can see that you have got wrong is that your first expression isn't returning a boolean or anything sensible that could be converted to a boolean. Your first expression is always going to return a jQuery object that has no sensible interpretation as a boolean and what it does convert to is probably an unchanging interpretation. You are always best off returning something that has a well known boolean interpretation, if nothign else for the sake of readability.

The second thing is that you are putting a semicolon after each of your expressions which is wrong. In effect this is saying "end of construct" and so is breaking your ternary operator.

In this situation though you probably can do this a more easy way. If you use classes and the toggleClass method then you can easily get it to switch a class on and off and then you can put your styles in that class definition (Kudos to @yoavmatchulsky for suggesting use of classes up there in comments).

A fiddle of this is found here: http://jsfiddle.net/chrisvenus/wSMnV/ (based on the original)

How to add/update child entities when updating a parent entity in EF

@Charles McIntosh really gave me the answer for my situation in that the passed in model was detached. For me what ultimately worked was saving the passed in model first... then continuing to add the children as I already was before:

public async Task<IHttpActionResult> GetUPSFreight(PartsExpressOrder order)
{
    db.Entry(order).State = EntityState.Modified;
    db.SaveChanges();
  ...
}

Error inflating class android.support.v7.widget.Toolbar?

If you are using new androidx implementations, when typing Toolbar, the Studio will autocomplete it to android.support.v7.widget.Toolbar, but you should use androidx.appcompat.widget.Toolbar instead, otherwise you will get this error.

How do you stretch an image to fill a <div> while keeping the image's aspect-ratio?

This did the trick for me

div img {
    width: 100%;
    min-height: 500px;
    width: 100vw;
    height: 100vh;
    object-fit: cover;
}

Initialization of an ArrayList in one line

Try with this code line:

Collections.singletonList(provider)

Calculate number of hours between 2 dates in PHP

<?
     $day1 = "2014-01-26 11:30:00";
     $day1 = strtotime($day1);
     $day2 = "2014-01-26 12:30:00";
     $day2 = strtotime($day2);

   $diffHours = round(($day2 - $day1) / 3600);

   echo $diffHours;

?>

How to get the text of the selected value of a dropdown list?

The easiest way is through css3 $("select option:selected") and then use the .text() or .html() function. depending on what you want to have.

Representing Directory & File Structure in Markdown Syntax

If you're using VS Code, this is an awesome extension for generating file trees.

Added directly to markdown...

quakehunter
 ? client
 ? node_modules
 ? server
 ? ? index.js
 ? .gitignore
 ? package-lock.json
 ? package.json

sudo: port: command not found

Make sure to delete ~/.bash_profile and ~/.bash_login so that .profile can work. This worked for me http://johnnywey.wordpress.com/2008/04/17/fixing-bash-profile-in-os-x/

How can I troubleshoot Python "Could not find platform independent libraries <prefix>"

If you made a virtual env, then deleted that python installation, you'll get the same error. Just rm -r your venv folder, then recreate it with a valid python location and do pip install -r requirements.txt and you'll be all set (assuming you got your requirements.txt right).

How to vertically center content with variable height within a div?

This is something I have needed to do many times and a consistent solution still requires you add a little non-semantic markup and some browser specific hacks. When we get browser support for css 3 you'll get your vertical centering without sinning.

For a better explanation of the technique you can look the article I adapted it from, but basically it involves adding an extra element and applying different styles in IE and browsers that support position:table\table-cell on non-table elements.

<div class="valign-outer">
    <div class="valign-middle">
        <div class="valign-inner">
            Excuse me. What did you sleep in your clothes again last night. Really. You're gonna be in the car with her. Hey, not too early I sleep in on Saturday. Oh, McFly, your shoe's untied. Don't be so gullible, McFly. You got the place fixed up nice, McFly. I have you're car towed all the way to your house and all you've got for me is light beer. What are you looking at, butthead. Say hi to your mom for me.
        </div>
    </div>
</div>

<style>
    /* Non-structural styling */
    .valign-outer { height: 400px; border: 1px solid red; }
    .valign-inner { border: 1px solid blue; }
</style>

<!--[if lte IE 7]>
<style>
    /* For IE7 and earlier */
    .valign-outer { position: relative; overflow: hidden; }
    .valign-middle { position: absolute; top: 50%; }
    .valign-inner { position: relative; top: -50% }
</style>
<![endif]-->
<!--[if gt IE 7]> -->
<style>
    /* For other browsers */
    .valign-outer { position: static; display: table; overflow: hidden; }
    .valign-middle { position: static; display: table-cell; vertical-align: middle; width: 100%; }
</style>

There are many ways (hacks) to apply styles in specific sets of browsers. I used conditional comments but look at the article linked above to see two other techniques.

Note: There are simple ways to get vertical centering if you know some heights in advance, if you are trying to center a single line of text, or in several other cases. If you have more details then throw them in because there may be a method that doesn't require browser hacks or non-semantic markup.

Update: We are beginning to get better browser support for CSS3, bringing both flex-box and transforms as alternative methods for getting vertical centering (among other effects). See this other question for more information about modern methods, but keep in mind that browser support is still sketchy for CSS3.

Turn off warnings and errors on PHP and MySQL

PHP error_reporting reference:

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

// Report simple running errors
error_reporting(E_ERROR | E_WARNING | E_PARSE);

// Reporting E_NOTICE can be good too (to report uninitialized
// variables or catch variable name misspellings ...)
error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);

// Report all errors except E_NOTICE
// This is the default value set in php.ini
error_reporting(E_ALL ^ E_NOTICE);

// Report all PHP errors (see changelog)
error_reporting(E_ALL);

// Report all PHP errors
error_reporting(-1);

// Same as error_reporting(E_ALL);
ini_set('error_reporting', E_ALL);

How do I concatenate a string with a variable?

It's just like you did. And I'll give you a small tip for these kind of silly things: just use the browser url box to try js syntax. for example, write this: javascript:alert("test"+5) and you have your answer. The problem in your code is probably that this element does not exist in your document... maybe it's inside a form or something. You can test this too by writing in the url: javascript:alert(document.horseThumb_5) to check where your mistake is.

MySQL: #126 - Incorrect key file for table

repair table myschema.mytable;

javax.xml.bind.UnmarshalException: unexpected element. Expected elements are (none)

When you generate a JAXB model from an XML Schema, global elements that correspond to named complex types will have that metadata captured as an @XmlElementDecl annotation on a create method in the ObjectFactory class. Since you are creating the JAXBContext on just the DocumentType class this metadata isn't being processed. If you generated your JAXB model from an XML Schema then you should create the JAXBContext on the generated package name or ObjectFactory class to ensure all the necessary metadata is processed.

Example solution:

JAXBContext jaxbContext = JAXBContext.newInstance(my.generatedschema.dir.ObjectFactory.class);
DocumentType documentType = ((JAXBElement<DocumentType>) jaxbContext.createUnmarshaller().unmarshal(inputStream)).getValue();

Resize Cross Domain Iframe Height

If you have access to manipulate the code of the site you are loading, the following should provide a comprehensive method to updating the height of the iframe container anytime the height of the framed content changes.

Add the following code to the pages you are loading (perhaps in a header). This code sends a message containing the height of the HTML container any time the DOM is updated (if you're lazy loading) or the window is resized (when the user modifies the browser).

window.addEventListener("load", function(){
    if(window.self === window.top) return; // if w.self === w.top, we are not in an iframe 
    send_height_to_parent_function = function(){
        var height = document.getElementsByTagName("html")[0].clientHeight;
        //console.log("Sending height as " + height + "px");
        parent.postMessage({"height" : height }, "*");
    }
    // send message to parent about height updates
    send_height_to_parent_function(); //whenever the page is loaded
    window.addEventListener("resize", send_height_to_parent_function); // whenever the page is resized
    var observer = new MutationObserver(send_height_to_parent_function);           // whenever DOM changes PT1
    var config = { attributes: true, childList: true, characterData: true, subtree:true}; // PT2
    observer.observe(window.document, config);                                            // PT3 
});

Add the following code to the page that the iframe is stored on. This will update the height of the iframe, given that the message came from the page that that iframe loads.

<script>
window.addEventListener("message", function(e){
    var this_frame = document.getElementById("healthy_behavior_iframe");
    if (this_frame.contentWindow === e.source) {
        this_frame.height = e.data.height + "px";
        this_frame.style.height = e.data.height + "px";
    }
})
</script>

CSS3 opacity gradient?

Except using css mask answered by @vals, you can also use transparency gradient background and set background-clip to text.

Create proper gradient:

background: linear-gradient(to bottom, rgba(0, 0, 0, 1) 0%, rgba(0, 0, 0, 0) 100%);

Then clip the backgroud with text:

background-clip: text;
color: transparent;

Demo

https://jsfiddle.net/simonmysun/2h61Ljbn/4/

Tested under Chrome 75 under Windows 10.

Supported platforms:

How to install mongoDB on windows?

I realize you've already accepted an answer for this, but I wrote this short howto article to install mongodb into the c:\wamp directory and run it as a service. Here is the gist of it.

Create these directories

mkdir c:\wamp\bin\mongodb\mongodb-win32...2.x.x\data
mkdir c:\wamp\bin\mongodb\mongodb-win32...2.x.x\data\db
mkdir c:\wamp\bin\mongodb\mongodb-win32...2.x.x\logs
mkdir c:\wamp\bin\mongodb\mongodb-win32...2.x.x\conf

Download and extract win32 binaries into c:\wamp directory along side mysql, apache.

mongodb download page

Create a mongo.conf file

c:\wamp\bin\mongodb\mongodb-win32…2.x.x\conf\mongodb.conf

# mongodb.conf

# data lives here
dbpath=C:\wamp\bin\mongodb\mongodb-win32...2.x.x\data\db

# where to log
logpath=C:\wamp\bin\mongodb\mongodb-win32...2.x.x\logs\mongodb.log
logappend=true

# only run on localhost for development
bind_ip = 127.0.0.1                                                             

port = 27017
rest = true

Install as a service

mongod.exe --install --config c:\wamp\bin\mongodb\mongodb-win32...2.x.x\conf\mongodb.conf --logpath c:\wamp\bin\mongodb\mongodb-win32...2.x.x\logs\mongodb.log

Set service to automatic and start it using services.msc

Add path to mongo.exe to your path

Need more details? Read the full article here...

Installing MongoDB on Windows the WAMP way

Uses of content-disposition in an HTTP response header

This header is defined in RFC 2183, so that would be the best place to start reading.

Permitted values are those registered with the Internet Assigned Numbers Authority (IANA); their registry of values should be seen as the definitive source.

Shortcut key for commenting out lines of Python code in Spyder

on Windows F9 to run single line

Select the lines which you want to run on console and press F9 button for multi line

What are unit tests, integration tests, smoke tests, and regression tests?

  • Integration testing: Integration testing is the integrate another element
  • Smoke testing: Smoke testing is also known as build version testing. Smoke testing is the initial testing process exercised to check whether the software under test is ready/stable for further testing.
  • Regression testing: Regression testing is repeated testing. Whether new software is effected in another module or not.
  • Unit testing: It is a white box testing. Only developers involve in it

Is there a way to automatically generate getters and setters in Eclipse?

Bring up the context menu (i.e. right click) in the source code window of the desired class. Then select the Source submenu; from that menu selecting Generate Getters and Setters... will cause a wizard window to appear.

Source -> Generate Getters and Setters...

Select the variables you wish to create getters and setters for and click OK.

How to call a PHP function on the click of a button

You can write like this in JavaScript or jQuery Ajax and call the file

_x000D_
_x000D_
$('#btn').click(function(){_x000D_
  $.ajax({_x000D_
    url:'test.php?call=true',_x000D_
    type:'GET',_x000D_
    success:function(data){_x000D_
    body.append(data);_x000D_
    }_x000D_
  });_x000D_
})
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.1/jquery.min.js"></script>_x000D_
<form  method='get' >_x000D_
_x000D_
  <input type="button" id="btn" value="click">_x000D_
</form>_x000D_
_x000D_
<?php_x000D_
    if(isset($_GET['call'])){_x000D_
_x000D_
        function anyfunction(){_x000D_
            echo "added";_x000D_
_x000D_
            // Your funtion code_x000D_
        }_x000D_
    }_x000D_
?>
_x000D_
_x000D_
_x000D_

Android: Creating a Circular TextView?

Try out below drawable file. Create file named "circle" in your res/drawable folder and copy below code:

   <?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval" >

    <solid android:color="#FFFFFF" />

    <stroke
        android:width="1dp"
        android:color="#4a6176" />

    <padding
        android:left="10dp"
        android:right="10dp"
        android:top="10dp"
        android:bottom="10dp"
         />

    <corners android:radius="10dp" />

</shape>

Apply it in your TextView as below:

<TextView
        android:id="@+id/tvSummary1"
        android:layout_width="270dp"
        android:layout_height="60dp"
        android:text="Hello World" 
        android:gravity="left|center_vertical"
        android:background="@drawable/round_bg">

    </TextView>

enter image description here

How to get JQuery.trigger('click'); to initiate a mouse click

Technically not an answer to this, but a good use of the accepted answer (https://stackoverflow.com/a/20928975/82028) to create next and prev buttons for the tabs on jQuery ACF fields:

$('.next').click(function () {
    $('#primary li.active').next().find('.acf-tab-button')[0].click();
});

$('.prev').click(function () {
    $('#primary li.active').prev().find('.acf-tab-button')[0].click();
});

How to add action listener that listens to multiple buttons

I use "e.getActionCommand().contains(CharSecuence s)", since I´m coming from an MVC context, and the Button is declared in the View class, but the actionPerformed call occurs in the controller.

public View() {
    ....
    buttonPlus = new Button("+");
    buttonMinus = new Button("-");
    ....
}

public void addController(ActionListener controller) {
    buttonPlus.addActionListener(controller);
    buttonMinus.addActionListener(controller);
}

My controller class implements ActionListener, and so, when overriding actionPerformed:

public void actionPerformed(ActionEvent e) {
    if(e.getActionCommand().contains("+")) {
        //do some action on the model
    } else if (e.getActionCommand().contains("-")) {
       //do some other action on the model
    }
}

I hope this other answer is also useful.

How do I append a node to an existing XML file in java

You can parse the existing XML file into DOM and append new elements to the DOM. Very similar to what you did with creating brand new XML. I am assuming you do not have to worry about duplicate server. If you do have to worry about that, you will have to go through the elements in the DOM to check for duplicates.

DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();

/* parse existing file to DOM */
Document document = documentBuilder.parse(new File("exisgint/xml/file"));

Element root = document.getDocumentElement();

for (Server newServer : Collection<Server> bunchOfNewServers){
  Element server = Document.createElement("server");
  /* create and setup the server node...*/

 root.appendChild(server);
}

/* use whatever method to output DOM to XML (for example, using transformer like you did).*/

How do I get the domain originating the request in express.js?

Instead of:

var host = req.get('host');
var origin = req.get('origin');

you can also use:

var host = req.headers.host;
var origin = req.headers.origin;

Serializing with Jackson (JSON) - getting "No serializer found"?

If you use Lomdok libraray (https://projectlombok.org/) then add @Data (https://projectlombok.org/features/Data) annotation to your data object class.

Could not create the Java virtual machine

Set the JVM memory:

export _JAVA_OPTIONS=-Xmx512M

How to unbind a listener that is calling event.preventDefault() (using jQuery)?

I'm not sure you're what you mean: but here's a solution for a similar (and possibly the same) problem...

I often use preventDefault() to intercept items. However: it's not the only method of interception... often you may just want a "question" following which behaviour continues as before, or stops. In a recent case I used the following solution:

$("#content").on('click', '#replace', (function(event){ return confirm('Are you sure you want to do that?') }));

Basically, the "prevent default" is meant to intercept and do something else: the "confirm" is designed for use in ... well - confirming!

How do I view the list of functions a Linux shared library is exporting?

What you need is nm and its -D option:

$ nm -D /usr/lib/libopenal.so.1
.
.
.
00012ea0 T alcSetThreadContext
000140f0 T alcSuspendContext
         U atanf
         U calloc
.
.
.

Exported sumbols are indicated by a T. Required symbols that must be loaded from other shared objects have a U. Note that the symbol table does not include just functions, but exported variables as well.

See the nm manual page for more information.

Is there any way to show a countdown on the lockscreen of iphone?

There is no way to display interactive elements on the lockscreen or wallpaper with a non jailbroken iPhone.

I would recommend Countdown Widget it's free an you can display countdowns in the notification center which you can also access from your lockscreen.

"Unknown class <MyClass> in Interface Builder file" error at runtime

I added the file Under Build Phase in Targets and the issue got resolved. For the steps to add the file, see my answer at:

Apple Mach-O Linker error (APActivityIcon)

"You have mail" message in terminal, os X

Probably it is some message from your system.

Type in terminal:

man mail

, and see how can you get this message from your system.

How to get UTC value for SYSDATE on Oracle

I'm using:

SELECT CAST(SYSTIMESTAMP AT TIME ZONE 'UTC' AS DATE) FROM DUAL;

It's working fine for me.

How to send file contents as body entity using cURL

I believe you're looking for the @filename syntax, e.g.:

strip new lines

curl --data "@/path/to/filename" http://...

keep new lines

curl --data-binary "@/path/to/filename" http://...

curl will strip all newlines from the file. If you want to send the file with newlines intact, use --data-binary in place of --data

Can local storage ever be considered secure?

This is a really interesting article here. I'm considering implementing JS encryption for offering security when using local storage. It's absolutely clear that this will only offer protection if the device is stolen (and is implemented correctly). It won't offer protection against keyloggers etc. However this is not a JS issue as the keylogger threat is a problem of all applications, regardless of their execution platform (browser, native). As to the article "JavaScript Crypto Considered Harmful" referenced in the first answer, I have one criticism; it states "You could use SSL/TLS to solve this problem, but that's expensive and complicated". I think this is a very ambitious claim (and possibly rather biased). Yes, SSL has a cost, but if you look at the cost of developing native applications for multiple OS, rather than web-based due to this issue alone, the cost of SSL becomes insignificant.

My conclusion - There is a place for client-side encryption code, however as with all applications the developers must recognise it's limitations and implement if suitable for their needs, and ensuring there are ways of mitigating it's risks.

Json.net serialize/deserialize derived types?

Use this JsonKnownTypes, it's very similar way to use, it just add discriminator to json:

[JsonConverter(typeof(JsonKnownTypeConverter<BaseClass>))]
[JsonKnownType(typeof(Base), "base")]
[JsonKnownType(typeof(Derived), "derived")]
public class Base
{
    public string Name;
}
public class Derived : Base
{
    public string Something;
}

Now when you serialize object in json will be add "$type" with "base" and "derived" value and it will be use for deserialize

Serialized list example:

[
    {"Name":"some name", "$type":"base"},
    {"Name":"some name", "Something":"something", "$type":"derived"}
]

how do I get eclipse to use a different compiler version for Java?

From the menu bar: Project -> Properties -> Java Compiler

Enable project specific settings (checked) Uncheck "use Compliance from execution environment '.... Select the desired "compiler compliance level"

That will allow you to compile "1.5" code using a "1.6" JDK.

If you want to acutally use a 1.5 JDK to produce "1.5" compliant code, then install a suitable 1.5 JDK and tell eclipse where it is installed via:

Window -> preferences -> Installed JREs

And then go back to your project

Project -> properties -> Java Build Path -> libraries

remove the 1.6 system libaries, and: add library... -> JRE System LIbrary -> Alternate JRE -> The JRE you want.

Verify that the correct JRE is on the project's build path, save everything, and enjoy!

Difference between break and continue statement

here's the semantic of break:

int[] a = new int[] { 1, 3, 4, 6, 7, 9, 10 };
// find 9
for(int i = 0; i < a.Length; i++)
{
    if (a[i] == 9) 
        goto goBreak;

    Console.WriteLine(a[i].ToString());      
}
goBreak:;

here's the semantic of continue:

int[] a = new int[] { 1, 3, 4, 6, 7, 9, 10 };
// skip all odds
for(int i = 0; i < a.Length; i++)
{
    if (a[i] % 2 == 1) 
        goto goContinue;

    Console.WriteLine(a[i].ToString());      

goContinue:;
}

How to trigger SIGUSR1 and SIGUSR2?

They are user-defined signals, so they aren't triggered by any particular action. You can explicitly send them programmatically:

#include <signal.h>

kill(pid, SIGUSR1);

where pid is the process id of the receiving process. At the receiving end, you can register a signal handler for them:

#include <signal.h>

void my_handler(int signum)
{
    if (signum == SIGUSR1)
    {
        printf("Received SIGUSR1!\n");
    }
}

signal(SIGUSR1, my_handler);

Is there a macro to conditionally copy rows to another worksheet?

This is partially pseudocode, but you will want something like:

rows = ActiveSheet.UsedRange.Rows
n = 0

while n <= rows
  if ActiveSheet.Rows(n).Cells(DateColumnOrdinal).Value > '8/1/08' AND < '8/30/08' then
     ActiveSheet.Rows(n).CopyTo(DestinationSheet)
  endif
  n = n + 1
wend

unable to start mongodb local server

if you are running mongo for first time you might wanna set the path first

mongod --dbpath <path to the directory>

how to File.listFiles in alphabetical order?

In Java 8:

Arrays.sort(files, (a, b) -> a.getName().compareTo(b.getName()));

Reverse order:

Arrays.sort(files, (a, b) -> -a.getName().compareTo(b.getName()));

Activity <App Name> has leaked ServiceConnection <ServiceConnection Name>@438030a8 that was originally bound here

You can use:

@Override
public void onDestroy() {
    super.onDestroy();

    if (mServiceConn != null) {
        unbindService(mServiceConn);
    }
}

Error: Cannot match any routes. URL Segment: - Angular 2

Solved myself. Done some small structural changes also. Route from Component1 to Component2 is done by a single <router-outlet>. Component2 to Comonent3 and Component4 is done by multiple <router-outlet name= "xxxxx"> The resulting contents are :

Component1.html

<nav>
    <a routerLink="/two" class="dash-item">Go to 2</a>
</nav>
    <router-outlet></router-outlet>

Component2.html

 <a [routerLink]="['/two', {outlets: {'nameThree': ['three']}}]">In Two...Go to 3 ...       </a>
 <a [routerLink]="['/two', {outlets: {'nameFour': ['four']}}]">   In Two...Go to 4 ...</a>

 <router-outlet name="nameThree"></router-outlet>
 <router-outlet name="nameFour"></router-outlet>

The '/two' represents the parent component and ['three']and ['four'] represents the link to the respective children of component2 . Component3.html and Component4.html are the same as in the question.

router.module.ts

const routes: Routes = [
{
    path: '',
    redirectTo: 'one',
    pathMatch: 'full'
},
{
    path: 'two',
    component: ClassTwo, children: [

        {
            path: 'three',
            component: ClassThree,
            outlet: 'nameThree'
        },
        {
            path: 'four',
            component: ClassFour,
            outlet: 'nameFour'
        }
    ]
},];

npm ERR! code UNABLE_TO_GET_ISSUER_CERT_LOCALLY

I had this error when I tried to update npm, but had a really old version (1.3.6 !) installed from yum in AWS Linux. I was able to manually install a newer npm version and everything was remedied.

Rename a column in MySQL

for mysql version 5

alter table *table_name* change column *old_column_name* *new_column_name* datatype();

How to set username and password for SmtpClient object in .NET?

SmtpClient MyMail = new SmtpClient();
MailMessage MyMsg = new MailMessage();
MyMail.Host = "mail.eraygan.com";
MyMsg.Priority = MailPriority.High;
MyMsg.To.Add(new MailAddress(Mail));
MyMsg.Subject = Subject;
MyMsg.SubjectEncoding = Encoding.UTF8;
MyMsg.IsBodyHtml = true;
MyMsg.From = new MailAddress("username", "displayname");
MyMsg.BodyEncoding = Encoding.UTF8;
MyMsg.Body = Body;
MyMail.UseDefaultCredentials = false;
NetworkCredential MyCredentials = new NetworkCredential("username", "password");
MyMail.Credentials = MyCredentials;
MyMail.Send(MyMsg);

Java: Rotating Images

AffineTransform instances can be concatenated (added together). Therefore you can have a transform that combines 'shift to origin', 'rotate' and 'shift back to desired position'.

How do I configure PyCharm to run py.test tests?

I'm using 2018.2

I do Run -> Edit Configurations... Then click the + in the upper left of the modal dialog. Select "python tests" -> py.test Then I give it a name like "All test with py.test"

I select Target: module name and put in the module where my tests are (that is 'tests' for me) or the module where all my code is if my tests are mixed in with my code. This was tripping me up.

I set the Python interpreter.

I set the working directory to the project directory.

Best practice for REST token-based authentication with JAX-RS and Jersey

How token-based authentication works

In token-based authentication, the client exchanges hard credentials (such as username and password) for a piece of data called token. For each request, instead of sending the hard credentials, the client will send the token to the server to perform authentication and then authorization.

In a few words, an authentication scheme based on tokens follow these steps:

  1. The client sends their credentials (username and password) to the server.
  2. The server authenticates the credentials and, if they are valid, generate a token for the user.
  3. The server stores the previously generated token in some storage along with the user identifier and an expiration date.
  4. The server sends the generated token to the client.
  5. The client sends the token to the server in each request.
  6. The server, in each request, extracts the token from the incoming request. With the token, the server looks up the user details to perform authentication.
    • If the token is valid, the server accepts the request.
    • If the token is invalid, the server refuses the request.
  7. Once the authentication has been performed, the server performs authorization.
  8. The server can provide an endpoint to refresh tokens.

Note: The step 3 is not required if the server has issued a signed token (such as JWT, which allows you to perform stateless authentication).

What you can do with JAX-RS 2.0 (Jersey, RESTEasy and Apache CXF)

This solution uses only the JAX-RS 2.0 API, avoiding any vendor specific solution. So, it should work with JAX-RS 2.0 implementations, such as Jersey, RESTEasy and Apache CXF.

It is worthwhile to mention that if you are using token-based authentication, you are not relying on the standard Java EE web application security mechanisms offered by the servlet container and configurable via application's web.xml descriptor. It's a custom authentication.

Authenticating a user with their username and password and issuing a token

Create a JAX-RS resource method which receives and validates the credentials (username and password) and issue a token for the user:

@Path("/authentication")
public class AuthenticationEndpoint {

    @POST
    @Produces(MediaType.APPLICATION_JSON)
    @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
    public Response authenticateUser(@FormParam("username") String username, 
                                     @FormParam("password") String password) {

        try {

            // Authenticate the user using the credentials provided
            authenticate(username, password);

            // Issue a token for the user
            String token = issueToken(username);

            // Return the token on the response
            return Response.ok(token).build();

        } catch (Exception e) {
            return Response.status(Response.Status.FORBIDDEN).build();
        }      
    }

    private void authenticate(String username, String password) throws Exception {
        // Authenticate against a database, LDAP, file or whatever
        // Throw an Exception if the credentials are invalid
    }

    private String issueToken(String username) {
        // Issue a token (can be a random String persisted to a database or a JWT token)
        // The issued token must be associated to a user
        // Return the issued token
    }
}

If any exceptions are thrown when validating the credentials, a response with the status 403 (Forbidden) will be returned.

If the credentials are successfully validated, a response with the status 200 (OK) will be returned and the issued token will be sent to the client in the response payload. The client must send the token to the server in every request.

When consuming application/x-www-form-urlencoded, the client must to send the credentials in the following format in the request payload:

username=admin&password=123456

Instead of form params, it's possible to wrap the username and the password into a class:

public class Credentials implements Serializable {

    private String username;
    private String password;

    // Getters and setters omitted
}

And then consume it as JSON:

@POST
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public Response authenticateUser(Credentials credentials) {

    String username = credentials.getUsername();
    String password = credentials.getPassword();

    // Authenticate the user, issue a token and return a response
}

Using this approach, the client must to send the credentials in the following format in the payload of the request:

{
  "username": "admin",
  "password": "123456"
}

Extracting the token from the request and validating it

The client should send the token in the standard HTTP Authorization header of the request. For example:

Authorization: Bearer <token-goes-here>

The name of the standard HTTP header is unfortunate because it carries authentication information, not authorization. However, it's the standard HTTP header for sending credentials to the server.

JAX-RS provides @NameBinding, a meta-annotation used to create other annotations to bind filters and interceptors to resource classes and methods. Define a @Secured annotation as following:

@NameBinding
@Retention(RUNTIME)
@Target({TYPE, METHOD})
public @interface Secured { }

The above defined name-binding annotation will be used to decorate a filter class, which implements ContainerRequestFilter, allowing you to intercept the request before it be handled by a resource method. The ContainerRequestContext can be used to access the HTTP request headers and then extract the token:

@Secured
@Provider
@Priority(Priorities.AUTHENTICATION)
public class AuthenticationFilter implements ContainerRequestFilter {

    private static final String REALM = "example";
    private static final String AUTHENTICATION_SCHEME = "Bearer";

    @Override
    public void filter(ContainerRequestContext requestContext) throws IOException {

        // Get the Authorization header from the request
        String authorizationHeader =
                requestContext.getHeaderString(HttpHeaders.AUTHORIZATION);

        // Validate the Authorization header
        if (!isTokenBasedAuthentication(authorizationHeader)) {
            abortWithUnauthorized(requestContext);
            return;
        }

        // Extract the token from the Authorization header
        String token = authorizationHeader
                            .substring(AUTHENTICATION_SCHEME.length()).trim();

        try {

            // Validate the token
            validateToken(token);

        } catch (Exception e) {
            abortWithUnauthorized(requestContext);
        }
    }

    private boolean isTokenBasedAuthentication(String authorizationHeader) {

        // Check if the Authorization header is valid
        // It must not be null and must be prefixed with "Bearer" plus a whitespace
        // The authentication scheme comparison must be case-insensitive
        return authorizationHeader != null && authorizationHeader.toLowerCase()
                    .startsWith(AUTHENTICATION_SCHEME.toLowerCase() + " ");
    }

    private void abortWithUnauthorized(ContainerRequestContext requestContext) {

        // Abort the filter chain with a 401 status code response
        // The WWW-Authenticate header is sent along with the response
        requestContext.abortWith(
                Response.status(Response.Status.UNAUTHORIZED)
                        .header(HttpHeaders.WWW_AUTHENTICATE, 
                                AUTHENTICATION_SCHEME + " realm=\"" + REALM + "\"")
                        .build());
    }

    private void validateToken(String token) throws Exception {
        // Check if the token was issued by the server and if it's not expired
        // Throw an Exception if the token is invalid
    }
}

If any problems happen during the token validation, a response with the status 401 (Unauthorized) will be returned. Otherwise the request will proceed to a resource method.

Securing your REST endpoints

To bind the authentication filter to resource methods or resource classes, annotate them with the @Secured annotation created above. For the methods and/or classes that are annotated, the filter will be executed. It means that such endpoints will only be reached if the request is performed with a valid token.

If some methods or classes do not need authentication, simply do not annotate them:

@Path("/example")
public class ExampleResource {

    @GET
    @Path("{id}")
    @Produces(MediaType.APPLICATION_JSON)
    public Response myUnsecuredMethod(@PathParam("id") Long id) {
        // This method is not annotated with @Secured
        // The authentication filter won't be executed before invoking this method
        ...
    }

    @DELETE
    @Secured
    @Path("{id}")
    @Produces(MediaType.APPLICATION_JSON)
    public Response mySecuredMethod(@PathParam("id") Long id) {
        // This method is annotated with @Secured
        // The authentication filter will be executed before invoking this method
        // The HTTP request must be performed with a valid token
        ...
    }
}

In the example shown above, the filter will be executed only for the mySecuredMethod(Long) method because it's annotated with @Secured.

Identifying the current user

It's very likely that you will need to know the user who is performing the request agains your REST API. The following approaches can be used to achieve it:

Overriding the security context of the current request

Within your ContainerRequestFilter.filter(ContainerRequestContext) method, a new SecurityContext instance can be set for the current request. Then override the SecurityContext.getUserPrincipal(), returning a Principal instance:

final SecurityContext currentSecurityContext = requestContext.getSecurityContext();
requestContext.setSecurityContext(new SecurityContext() {

        @Override
        public Principal getUserPrincipal() {
            return () -> username;
        }

    @Override
    public boolean isUserInRole(String role) {
        return true;
    }

    @Override
    public boolean isSecure() {
        return currentSecurityContext.isSecure();
    }

    @Override
    public String getAuthenticationScheme() {
        return AUTHENTICATION_SCHEME;
    }
});

Use the token to look up the user identifier (username), which will be the Principal's name.

Inject the SecurityContext in any JAX-RS resource class:

@Context
SecurityContext securityContext;

The same can be done in a JAX-RS resource method:

@GET
@Secured
@Path("{id}")
@Produces(MediaType.APPLICATION_JSON)
public Response myMethod(@PathParam("id") Long id, 
                         @Context SecurityContext securityContext) {
    ...
}

And then get the Principal:

Principal principal = securityContext.getUserPrincipal();
String username = principal.getName();

Using CDI (Context and Dependency Injection)

If, for some reason, you don't want to override the SecurityContext, you can use CDI (Context and Dependency Injection), which provides useful features such as events and producers.

Create a CDI qualifier:

@Qualifier
@Retention(RUNTIME)
@Target({ METHOD, FIELD, PARAMETER })
public @interface AuthenticatedUser { }

In your AuthenticationFilter created above, inject an Event annotated with @AuthenticatedUser:

@Inject
@AuthenticatedUser
Event<String> userAuthenticatedEvent;

If the authentication succeeds, fire the event passing the username as parameter (remember, the token is issued for a user and the token will be used to look up the user identifier):

userAuthenticatedEvent.fire(username);

It's very likely that there's a class that represents a user in your application. Let's call this class User.

Create a CDI bean to handle the authentication event, find a User instance with the correspondent username and assign it to the authenticatedUser producer field:

@RequestScoped
public class AuthenticatedUserProducer {

    @Produces
    @RequestScoped
    @AuthenticatedUser
    private User authenticatedUser;

    public void handleAuthenticationEvent(@Observes @AuthenticatedUser String username) {
        this.authenticatedUser = findUser(username);
    }

    private User findUser(String username) {
        // Hit the the database or a service to find a user by its username and return it
        // Return the User instance
    }
}

The authenticatedUser field produces a User instance that can be injected into container managed beans, such as JAX-RS services, CDI beans, servlets and EJBs. Use the following piece of code to inject a User instance (in fact, it's a CDI proxy):

@Inject
@AuthenticatedUser
User authenticatedUser;

Note that the CDI @Produces annotation is different from the JAX-RS @Produces annotation:

Be sure you use the CDI @Produces annotation in your AuthenticatedUserProducer bean.

The key here is the bean annotated with @RequestScoped, allowing you to share data between filters and your beans. If you don't wan't to use events, you can modify the filter to store the authenticated user in a request scoped bean and then read it from your JAX-RS resource classes.

Compared to the approach that overrides the SecurityContext, the CDI approach allows you to get the authenticated user from beans other than JAX-RS resources and providers.

Supporting role-based authorization

Please refer to my other answer for details on how to support role-based authorization.

Issuing tokens

A token can be:

  • Opaque: Reveals no details other than the value itself (like a random string)
  • Self-contained: Contains details about the token itself (like JWT).

See details below:

Random string as token

A token can be issued by generating a random string and persisting it to a database along with the user identifier and an expiration date. A good example of how to generate a random string in Java can be seen here. You also could use:

Random random = new SecureRandom();
String token = new BigInteger(130, random).toString(32);

JWT (JSON Web Token)

JWT (JSON Web Token) is a standard method for representing claims securely between two parties and is defined by the RFC 7519.

It's a self-contained token and it enables you to store details in claims. These claims are stored in the token payload which is a JSON encoded as Base64. Here are some claims registered in the RFC 7519 and what they mean (read the full RFC for further details):

  • iss: Principal that issued the token.
  • sub: Principal that is the subject of the JWT.
  • exp: Expiration date for the token.
  • nbf: Time on which the token will start to be accepted for processing.
  • iat: Time on which the token was issued.
  • jti: Unique identifier for the token.

Be aware that you must not store sensitive data, such as passwords, in the token.

The payload can be read by the client and the integrity of the token can be easily checked by verifying its signature on the server. The signature is what prevents the token from being tampered with.

You won't need to persist JWT tokens if you don't need to track them. Althought, by persisting the tokens, you will have the possibility of invalidating and revoking the access of them. To keep the track of JWT tokens, instead of persisting the whole token on the server, you could persist the token identifier (jti claim) along with some other details such as the user you issued the token for, the expiration date, etc.

When persisting tokens, always consider removing the old ones in order to prevent your database from growing indefinitely.

Using JWT

There are a few Java libraries to issue and validate JWT tokens such as:

To find some other great resources to work with JWT, have a look at http://jwt.io.

Handling token revocation with JWT

If you want to revoke tokens, you must keep the track of them. You don't need to store the whole token on server side, store only the token identifier (that must be unique) and some metadata if you need. For the token identifier you could use UUID.

The jti claim should be used to store the token identifier on the token. When validating the token, ensure that it has not been revoked by checking the value of the jti claim against the token identifiers you have on server side.

For security purposes, revoke all the tokens for a user when they change their password.

Additional information

  • It doesn't matter which type of authentication you decide to use. Always do it on the top of a HTTPS connection to prevent the man-in-the-middle attack.
  • Take a look at this question from Information Security for more information about tokens.
  • In this article you will find some useful information about token-based authentication.

How to clear/remove observable bindings in Knockout.js?

I had a memory leak problem recently and ko.cleanNode(element); wouldn't do it for me -ko.removeNode(element); did. Javascript + Knockout.js memory leak - How to make sure object is being destroyed?

How to use HTML Agility pack

I don't know if this will be of any help to you, but I have written a couple of articles which introduce the basics.

The next article is 95% complete, I just have to write up explanations of the last few parts of the code I have written. If you are interested then I will try to remember to post here when I publish it.

Dump a list in a pickle file and retrieve it back later

Pickling will serialize your list (convert it, and it's entries to a unique byte string), so you can save it to disk. You can also use pickle to retrieve your original list, loading from the saved file.

So, first build a list, then use pickle.dump to send it to a file...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist = ['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>> 
>>> import pickle
>>> 
>>> with open('parrot.pkl', 'wb') as f:
...   pickle.dump(mylist, f)
... 
>>> 

Then quit and come back later… and open with pickle.load...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pickle
>>> with open('parrot.pkl', 'rb') as f:
...   mynewlist = pickle.load(f)
... 
>>> mynewlist
['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>>

How can I convert a char to int in Java?

I you have the char '9', it will store its ASCII code, so to get the int value, you have 2 ways

char x = '9';
int y = Character.getNumericValue(x);   //use a existing function
System.out.println(y + " " + (y + 1));  // 9  10

or

char x = '9';
int y = x - '0';                        // substract '0' code to get the difference
System.out.println(y + " " + (y + 1));  // 9  10

And it fact, this works also :

char x = 9;
System.out.println(">" + x + "<");     //>  < prints a horizontal tab
int y = (int) x;
System.out.println(y + " " + (y + 1)); //9 10

You store the 9 code, which corresponds to a horizontal tab (you can see when print as String, bu you can also use it as int as you see above

How do I download and save a file locally on iOS using objective C?

I think a much easier way is to use ASIHTTPRequest. Three lines of code can accomplish this:

ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDownloadDestinationPath:@"/path/to/my_file.txt"];
[request startSynchronous];

Link to Reference

UPDATE: I should mention that ASIHTTPRequest is no longer maintained. The author has specifically advised people to use other framework instead, like AFNetworking

How to implement one-to-one, one-to-many and many-to-many relationships while designing tables?

Here are some real-world examples of the types of relationships:

One-to-one (1:1)

A relationship is one-to-one if and only if one record from table A is related to a maximum of one record in table B.

To establish a one-to-one relationship, the primary key of table B (with no orphan record) must be the secondary key of table A (with orphan records).

For example:

CREATE TABLE Gov(
    GID number(6) PRIMARY KEY, 
    Name varchar2(25), 
    Address varchar2(30), 
    TermBegin date,
    TermEnd date
); 

CREATE TABLE State(
    SID number(3) PRIMARY KEY,
    StateName varchar2(15),
    Population number(10),
    SGID Number(4) REFERENCES Gov(GID), 
    CONSTRAINT GOV_SDID UNIQUE (SGID)
);

INSERT INTO gov(GID, Name, Address, TermBegin) 
values(110, 'Bob', '123 Any St', '1-Jan-2009');

INSERT INTO STATE values(111, 'Virginia', 2000000, 110);

One-to-many (1:M)

A relationship is one-to-many if and only if one record from table A is related to one or more records in table B. However, one record in table B cannot be related to more than one record in table A.

To establish a one-to-many relationship, the primary key of table A (the "one" table) must be the secondary key of table B (the "many" table).

For example:

CREATE TABLE Vendor(
    VendorNumber number(4) PRIMARY KEY,
    Name varchar2(20),
    Address varchar2(20),
    City varchar2(15),
    Street varchar2(2),
    ZipCode varchar2(10),
    Contact varchar2(16),
    PhoneNumber varchar2(12),
    Status varchar2(8),
    StampDate date
);

CREATE TABLE Inventory(
    Item varchar2(6) PRIMARY KEY,
    Description varchar2(30),
    CurrentQuantity number(4) NOT NULL,
    VendorNumber number(2) REFERENCES Vendor(VendorNumber),
    ReorderQuantity number(3) NOT NULL
);

Many-to-many (M:M)

A relationship is many-to-many if and only if one record from table A is related to one or more records in table B and vice-versa.

To establish a many-to-many relationship, create a third table called "ClassStudentRelation" which will have the primary keys of both table A and table B.

CREATE TABLE Class(
    ClassID varchar2(10) PRIMARY KEY, 
    Title varchar2(30),
    Instructor varchar2(30), 
    Day varchar2(15), 
    Time varchar2(10)
);

CREATE TABLE Student(
    StudentID varchar2(15) PRIMARY KEY, 
    Name varchar2(35),
    Major varchar2(35), 
    ClassYear varchar2(10), 
    Status varchar2(10)
);  

CREATE TABLE ClassStudentRelation(
    StudentID varchar2(15) NOT NULL,
    ClassID varchar2(14) NOT NULL,
    FOREIGN KEY (StudentID) REFERENCES Student(StudentID), 
    FOREIGN KEY (ClassID) REFERENCES Class(ClassID),
    UNIQUE (StudentID, ClassID)
);

php stdClass to array

Please use following php function to convert php stdClass to array

get_object_vars($data)

How do I load external fonts into an HTML document?

Regarding Jay Stevens answer: "The fonts available to use in an HTML file have to be present on the user's machine and accessible from the web browser, so unless you want to distribute the fonts to the user's machine via a separate external process, it can't be done." That's true.

But there is another way using javascript / canvas / flash - very good solution gives cufon: http://cufon.shoqolate.com/generate/ library that generates a very easy to use external fonts methods.

How to parse a JSON and turn its values into an Array?

for your example:

{'profiles': [{'name':'john', 'age': 44}, {'name':'Alex','age':11}]}

you will have to do something of this effect:

JSONObject myjson = new JSONObject(the_json);
JSONArray the_json_array = myjson.getJSONArray("profiles");

this returns the array object.

Then iterating will be as follows:

    int size = the_json_array.length();
    ArrayList<JSONObject> arrays = new ArrayList<JSONObject>();
    for (int i = 0; i < size; i++) {
        JSONObject another_json_object = the_json_array.getJSONObject(i);
            //Blah blah blah...
            arrays.add(another_json_object);
    }

//Finally
JSONObject[] jsons = new JSONObject[arrays.size()];
arrays.toArray(jsons);

//The end...

You will have to determine if the data is an array (simply checking that charAt(0) starts with [ character).

Hope this helps.

Get an image extension from an uploaded file in Laravel

 //working code from laravel 5.2

 public function store(Request $request)
 {
          $file = $request->file('file');
            if($file)
            {
                    $extension =  $file->clientExtension();
            }
            echo $extension;
 }

Include .so library in apk in android studio

I had the same problem. Check out the comment in https://gist.github.com/khernyo/4226923#comment-812526

It says:

for gradle android plugin v0.3 use "com.android.build.gradle.tasks.PackageApplication"

That should fix your problem.

Warp \ bend effect on a UIView?

What you show looks like a mesh warp. That would be straightforward using OpenGL, but "straightforward OpenGL" is like straightforward rocket science.

I wrote an iOS app for my company called Face Dancerthat's able to do 60 fps mesh warp animations of video from the built-in camera using OpenGL, but it was a lot of work. (It does funhouse mirror type changes to faces - think "fat booth" live, plus lots of other effects.)

"Input string was not in a correct format."

Please change your code like below.

  int QuestionID;

  bool IsIntValue = Int32.TryParse("YOUR-VARIABLE", out QuestionID);

  if (IsIntValue)
  {
      // YOUR CODE HERE  
  }

Hope i will be help.

Regex Match all characters between two strings

In case anyone is looking for an example of this within a Jenkins context. It parses the build.log and if it finds a match it fails the build with the match.

import java.util.regex.Matcher;
import java.util.regex.Pattern;

node{    
    stage("parse"){
        def file = readFile 'build.log'

        def regex = ~"(?s)(firstStringToUse(.*)secondStringToUse)"
        Matcher match = regex.matcher(file)
        match.find() {
            capturedText = match.group(1)
            error(capturedText)
        }
    }
}

Module AppRegistry is not registered callable module (calling runApplication)

import { AppRegistry } from 'react-native';

AppRegistry.registerComponent('your app name',  () => point);

Most efficient way to map function over numpy array

How about using numpy.vectorize.

import numpy as np
x = np.array([1, 2, 3, 4, 5])
squarer = lambda t: t ** 2
vfunc = np.vectorize(squarer)
vfunc(x)
# Output : array([ 1,  4,  9, 16, 25])

How to check if String value is Boolean type in Java?

Actually, checking for a Boolean type in a String (which is a type) is impossible. Basically you're asking how to do a 'string compare'.

Like others stated. You need to define when you want to return "true" or "false" (under what conditions). Do you want it to be case(in)sensitive? What if the value is null?

I think Boolean.valueOf() is your friend, javadoc says:

Returns a Boolean with a value represented by the specified String. The Boolean returned represents the value true if the string argument is not null and is equal, ignoring case, to the string "true".

Example: Boolean.valueOf("True") returns true.
Example: Boolean.valueOf("yes") returns false.

Angular 2 change event - model changes

If this helps you,

<input type="checkbox"  (ngModelChange)="mychange($event)" [ngModel]="mymodel">

mychange(val)
{
   console.log(val); // updated value
}

How to run Java program in command prompt

All you need to do is:

  • Build the mainjava class using the class path if any (optional)

    javac *.java [ -cp "wb.jar;"]

  • Create Manifest.txt file with content is:

    Main-Class: mainjava

  • Package the jar file for mainjava class

    jar cfm mainjava.jar Manifest.txt *.class

Then you can run this .jar file from cmd with class path (optional) and put arguments for it.

java [-cp "wb.jar;"] mainjava arg0 arg1 

HTH.

How do I grant read access for a user to a database in SQL Server?

This is a two-step process:

  1. you need to create a login to SQL Server for that user, based on its Windows account

    CREATE LOGIN [<domainName>\<loginName>] FROM WINDOWS;
    
  2. you need to grant this login permission to access a database:

    USE (your database)
    CREATE USER (username) FOR LOGIN (your login name)
    

Once you have that user in your database, you can give it any rights you want, e.g. you could assign it the db_datareader database role to read all tables.

USE (your database)
EXEC sp_addrolemember 'db_datareader', '(your user name)'

Selecting pandas column by location

You can access multiple columns by passing a list of column indices to dataFrame.ix.

For example:

>>> df = pandas.DataFrame({
             'a': np.random.rand(5),
             'b': np.random.rand(5),
             'c': np.random.rand(5),
             'd': np.random.rand(5)
         })

>>> df
          a         b         c         d
0  0.705718  0.414073  0.007040  0.889579
1  0.198005  0.520747  0.827818  0.366271
2  0.974552  0.667484  0.056246  0.524306
3  0.512126  0.775926  0.837896  0.955200
4  0.793203  0.686405  0.401596  0.544421

>>> df.ix[:,[1,3]]
          b         d
0  0.414073  0.889579
1  0.520747  0.366271
2  0.667484  0.524306
3  0.775926  0.955200
4  0.686405  0.544421

Convert JavaScript string in dot notation into an object reference

I copied the following from Ricardo Tomasi's answer and modified to also create sub-objects that don't yet exist as necessary. It's a little less efficient (more ifs and creating of empty objects), but should be pretty good.

Also, it'll allow us to do Object.prop(obj, 'a.b', false) where we couldn't before. Unfortunately, it still won't let us assign undefined...Not sure how to go about that one yet.

/**
 * Object.prop()
 *
 * Allows dot-notation access to object properties for both getting and setting.
 *
 * @param {Object} obj    The object we're getting from or setting
 * @param {string} prop   The dot-notated string defining the property location
 * @param {mixed}  val    For setting only; the value to set
 */
 Object.prop = function(obj, prop, val){
   var props = prop.split('.'),
       final = props.pop(),
       p;

   for (var i = 0; i < props.length; i++) {
     p = props[i];
     if (typeof obj[p] === 'undefined') {
       // If we're setting
       if (typeof val !== 'undefined') {
         // If we're not at the end of the props, keep adding new empty objects
         if (i != props.length)
           obj[p] = {};
       }
       else
         return undefined;
     }
     obj = obj[p]
   }
   return typeof val !== "undefined" ? (obj[final] = val) : obj[final]
 }

WAMP Server doesn't load localhost

I faced a similar problem. I tried everything with ports, hosts and config files.But nothing helped.

I checked apache error logs. They showed the following error

(OS 10038)An operation was attempted on something that is not a socket.  : AH00332: winnt_accept: getsockname error on listening socket, is IPv6 available?

Finally this is what solved my problem.

1) Goto command prompt and run it in administrative mode. In windows 7 you can do it by typing cmd in run and then pressing ctrl+shift+enter

2) run the following command: netsh winsock reset

3) Restart the system

position fixed is not working

My issue was that a parent element had transform: scale(1); this apparently makes it impossible for any element to be fixed inside it. By removing that everything works normally...

It seems to be like this in all browsers I tested (Chrome, Safari) so don't know if it comes from some strange web standard.

(It's a popup that goes from scale(0) to scale(1))

Can I run HTML files directly from GitHub, instead of just viewing their source?

I had the same problem for my project Ratio.js and here's what I did.

Problem: Github.com prevents files from rendering/executing when the source is viewed by setting the content type/MIME to plain text.

Solution: Have a web page import the files.

Example:

Use jsfiddle.net or jsbin.com to create a webpage online then save it. Navigate to your file in Github.com and click the 'raw' button to get the direct link to the file. From there, import the file using the appropriate tag and attribute.

<!DOCTYPE>
<html>
    <head>
        <link rel="stylesheet" href="http://code.jquery.com/qunit/git/qunit.css" type="text/css" media="screen" />
    </head>
    <body>
        <h1 id="qunit-header">QUnit example</h1>
        <h2 id="qunit-banner"></h2>
        <div id="qunit-testrunner-toolbar"></div>
        <h2 id="qunit-userAgent"></h2>
        <ol id="qunit-tests"></ol>
        <div id="qunit-fixture">test markup, will be hidden</div>
        <script src="http://code.jquery.com/jquery-latest.js"></script>
        <script type="text/javascript" src="http://code.jquery.com/qunit/git/qunit.js"></script>  
        <script type="text/javascript" src="https://raw.github.com/LarryBattle/Ratio.js/master/src/Ratio.js"></script>  
        <script type="text/javascript" src="https://raw.github.com/LarryBattle/Ratio.js/master/tests/js/Ratio-testcases.js"></script>  
    </body>
</html>

Live Demo: http://jsfiddle.net/jKu4q/2/

Note: Note for jsfiddle.net you can get direct access to the result page by adding show to the end of the url. Like so: http://jsfiddle.net/jKu4q/2/show

Or....you could create a project page and render your HTML files from there. You can create a project page at http://pages.github.com/.

Once created you can then access the link through http://*accountName*.github.com/*projectName*/ Example: http://larrybattle.github.com/Ratio.js/

How to center form in bootstrap 3

Many people advise using col- and col-offset- classes, but it doesn't work right for me, it centers the form only for a certain screen size, but if you change it, the markup slides out.

I found two ways to align form:

Use a custom CSS:

<div class=".center">
  <form>

  </form>
</div>

.center {
  margin: 0 auto;
  width: 100%;
}
form {
  margin: 0 auto;
  width: 500px; /*find your value*/
  text-align: center;
}

Original code

OR just copy a CSS class "justify-content-center" from bootstrap 4, it's very short:

.justify-content-center {
    -ms-flex-pack: center !important;
    justify-content: center !important;
}

And then use it:

<div class="container">
    <div class="row">
        <div class="form-inline justify-content-center">
        </div>
    </div>
</div>

Real mouse position in canvas

The easiest way to compute the correct mouse click or mouse move position on a canvas event is to use this little equation:

canvas.addEventListener('click', event =>
{
    let bound = canvas.getBoundingClientRect();

    let x = event.clientX - bound.left - canvas.clientLeft;
    let y = event.clientY - bound.top - canvas.clientTop;

    context.fillRect(x, y, 16, 16);
});

If the canvas has padding-left or padding-top, subtract x and y via:

x -= parseFloat(style['padding-left'].replace('px'));
y -= parseFloat(style['padding-top'].replace('px'));

Python: how to capture image from webcam on click using OpenCV

This is a simple program to capture an image from using a default camera. Also, It can Detect a human face.

import cv2
import sys
import logging as log
import datetime as dt
from time import sleep

cascPath = "haarcascade_frontalface_default.xml"
faceCascade = cv2.CascadeClassifier(cascPath)
log.basicConfig(filename='webcam.log',level=log.INFO)

video_capture = cv2.VideoCapture(0)
anterior = 0

while True:
    if not video_capture.isOpened():
        print('Unable to load camera.')
        sleep(5)
        pass

    # Capture frame-by-frame
    ret, frame = video_capture.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    faces = faceCascade.detectMultiScale(
        gray,
        scaleFactor=1.1,
        minNeighbors=5,
        minSize=(30, 30)
    )

    # Draw a rectangle around the faces
    for (x, y, w, h) in faces:
        cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)

    if anterior != len(faces):
        anterior = len(faces)
        log.info("faces: "+str(len(faces))+" at "+str(dt.datetime.now()))


    # Display the resulting frame
    cv2.imshow('Video', frame)

    if cv2.waitKey(1) & 0xFF == ord('s'): 

        check, frame = video_capture.read()
        cv2.imshow("Capturing", frame)
        cv2.imwrite(filename='saved_img.jpg', img=frame)
        video_capture.release()
        img_new = cv2.imread('saved_img.jpg', cv2.IMREAD_GRAYSCALE)
        img_new = cv2.imshow("Captured Image", img_new)
        cv2.waitKey(1650)
        print("Image Saved")
        print("Program End")
        cv2.destroyAllWindows()

        break
    elif cv2.waitKey(1) & 0xFF == ord('q'):
        print("Turning off camera.")
        video_capture.release()
        print("Camera off.")
        print("Program ended.")
        cv2.destroyAllWindows()
        break

    # Display the resulting frame
    cv2.imshow('Video', frame)

# When everything is done, release the capture
video_capture.release()
cv2.destroyAllWindows()

output

enter image description here

Also, You can check out my GitHub code

How can I perform a short delay in C# without using sleep?

If you're using .NET 4.5 you can use the new async/await framework to sleep without locking the thread.

How it works is that you mark the function in need of asynchronous operations, with the async keyword. This is just a hint to the compiler. Then you use the await keyword on the line where you want your code to run asynchronously and your program will wait without locking the thread or the UI. The method you call (on the await line) has to be marked with an async keyword as well and is usually named ending with Async, as in ImportFilesAsync.

What you need to do in your example is:

  1. Make sure your program has .Net Framework 4.5 as Target Framework
  2. Mark your function that needs to sleep with the async keyword (see example below)
  3. Add using System.Threading.Tasks; to your code.

Your code is now ready to use the Task.Delay method instead of the System.Threading.Thread.Sleep method (it is possible to use await on Task.Delay because Task.Delay is marked with async in its definition).

private async void button1_Click(object sender, EventArgs e)
{
    textBox1.Text += "\r\nThread Sleeps!";
    await Task.Delay(3000);
    textBox1.Text += "\r\nThread awakens!";
}

Here you can read more about Task.Delay and Await.

Extract a subset of a dataframe based on a condition involving a field

Here are the two main approaches. I prefer this one for its readability:

bar <- subset(foo, location == "there")

Note that you can string together many conditionals with & and | to create complex subsets.

The second is the indexing approach. You can index rows in R with either numeric, or boolean slices. foo$location == "there" returns a vector of T and F values that is the same length as the rows of foo. You can do this to return only rows where the condition returns true.

foo[foo$location == "there", ]

Jboss server error : Failed to start service jboss.deployment.unit."jbpm-console.war"

I had the exact same problem, found that I was missing

<mdb>  
  <resource-adapter-ref resource-adapter-name="hornetq-ra"/>  
  <bean-instance-pool-ref pool-name="mdb-strict-max-pool"/>  
</mdb>  

under

<subsystem xmlns="urn:jboss:domain:ejb3:1.2">  

in standalone/configuration/standalone.xml

How to handle windows file upload using Selenium WebDriver?

The below one had worked for me

webDriver.findElement(By.xpath("//input[@type='file' and @name='importFile']")).sendKeys("C:/path/to/file.jpg");

forEach() in React JSX does not output any HTML

You need to pass an array of element to jsx. The problem is that forEach does not return anything (i.e it returns undefined). So it's better to use map because map returns an array:

class QuestionSet extends Component {
render(){ 
    <div className="container">
       <h1>{this.props.question.text}</h1>
       {this.props.question.answers.map((answer, i) => {     
           console.log("Entered");                 
           // Return the element. Also pass key     
           return (<Answer key={answer} answer={answer} />) 
        })}
}

export default QuestionSet;

How to auto-indent code in the Atom editor?

You could also try to add a key mapping witch auto select all the code in file and indent it:

'atom-text-editor':
  'ctrl-alt-l': 'auto-indent:apply'

How can I count the rows with data in an Excel sheet?

This is what I finally came up with, which works great!

{=SUM(IF((ISTEXT('Worksheet Name!A:A))+(ISTEXT('CCSA Associates'!E:E)),1,0))-1}

Don't forget since it is an array to type the formula above without the "{}", and to CTRL + SHIFT + ENTER instead of just ENTER for the "{}" to appear and for it to be entered properly.

Remove folder and its contents from git/GitHub's history

I find that the --tree-filter option used in other answers can be very slow, especially on larger repositories with lots of commits.

Here is the method I use to completely remove a directory from the git history using the --index-filter option, which runs much quicker:

# Make a fresh clone of YOUR_REPO
git clone YOUR_REPO
cd YOUR_REPO

# Create tracking branches of all branches
for remote in `git branch -r | grep -v /HEAD`; do git checkout --track $remote ; done

# Remove DIRECTORY_NAME from all commits, then remove the refs to the old commits
# (repeat these two commands for as many directories that you want to remove)
git filter-branch --index-filter 'git rm -rf --cached --ignore-unmatch DIRECTORY_NAME/' --prune-empty --tag-name-filter cat -- --all
git for-each-ref --format="%(refname)" refs/original/ | xargs -n 1 git update-ref -d

# Ensure all old refs are fully removed
rm -Rf .git/logs .git/refs/original

# Perform a garbage collection to remove commits with no refs
git gc --prune=all --aggressive

# Force push all branches to overwrite their history
# (use with caution!)
git push origin --all --force
git push origin --tags --force

You can check the size of the repository before and after the gc with:

git count-objects -vH

How do I parallelize a simple Python loop?

There are a number of advantages to using Ray:

  • You can parallelize over multiple machines in addition to multiple cores (with the same code).
  • Efficient handling of numerical data through shared memory (and zero-copy serialization).
  • High task throughput with distributed scheduling.
  • Fault tolerance.

In your case, you could start Ray and define a remote function

import ray

ray.init()

@ray.remote(num_return_vals=3)
def calc_stuff(parameter=None):
    # Do something.
    return 1, 2, 3

and then invoke it in parallel

output1, output2, output3 = [], [], []

# Launch the tasks.
for j in range(10):
    id1, id2, id3 = calc_stuff.remote(parameter=j)
    output1.append(id1)
    output2.append(id2)
    output3.append(id3)

# Block until the results have finished and get the results.
output1 = ray.get(output1)
output2 = ray.get(output2)
output3 = ray.get(output3)

To run the same example on a cluster, the only line that would change would be the call to ray.init(). The relevant documentation can be found here.

Note that I'm helping to develop Ray.

How to remove entry from $PATH on mac

  1. echo $PATH and copy it's value
  2. export PATH=""
  3. export PATH="/path/you/want/to/keep"

How to enable named/bind/DNS full logging?

Run command rndc querylog on or add querylog yes; to options{}; section in named.conf to activate that channel.

Also make sure you’re checking correct directory if your bind is chrooted.

Mockito: Mock private field initialization

Mockito comes with a helper class to save you some reflection boiler plate code:

import org.mockito.internal.util.reflection.Whitebox;

//...

@Mock
private Person mockedPerson;
private Test underTest;

// ...

@Test
public void testMethod() {
    Whitebox.setInternalState(underTest, "person", mockedPerson);
    // ...
}

Update: Unfortunately the mockito team decided to remove the class in Mockito 2. So you are back to writing your own reflection boilerplate code, use another library (e.g. Apache Commons Lang), or simply pilfer the Whitebox class (it is MIT licensed).

Update 2: JUnit 5 comes with its own ReflectionSupport and AnnotationSupport classes that might be useful and save you from pulling in yet another library.

git: 'credential-cache' is not a git command

First run git config --global credential.helper wincred

Then go to: CONTROL PANEL\CREDENTIAL MANAGER\WINDOWS CREDENTIAL\GENERIC CREDENTIAL

then click in add a credential in Internet or network address: add git:https://{username}.github.com

User: {name}

Password: {Password}

Android Reading from an Input stream efficiently

The problem in your code is that it's creating lots of heavy String objects, copying their contents and performing operations on them. Instead, you should use StringBuilder to avoid creating new String objects on each append and to avoid copying the char arrays. The implementation for your case would be something like this:

BufferedReader r = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder total = new StringBuilder();
for (String line; (line = r.readLine()) != null; ) {
    total.append(line).append('\n');
}

You can now use total without converting it to String, but if you need the result as a String, simply add:

String result = total.toString();

I'll try to explain it better...

  • a += b (or a = a + b), where a and b are Strings, copies the contents of both a and b to a new object (note that you are also copying a, which contains the accumulated String), and you are doing those copies on each iteration.
  • a.append(b), where a is a StringBuilder, directly appends b contents to a, so you don't copy the accumulated string at each iteration.

Which equals operator (== vs ===) should be used in JavaScript comparisons?

In JavaScript it means of the same value and type.

For example,

4 == "4" // will return true

but

4 === "4" // will return false 

Postgresql GROUP_CONCAT equivalent?

This is probably a good starting point (version 8.4+ only):

SELECT id_field, array_agg(value_field1), array_agg(value_field2)
FROM data_table
GROUP BY id_field

array_agg returns an array, but you can CAST that to text and edit as needed (see clarifications, below).

Prior to version 8.4, you have to define it yourself prior to use:

CREATE AGGREGATE array_agg (anyelement)
(
    sfunc = array_append,
    stype = anyarray,
    initcond = '{}'
);

(paraphrased from the PostgreSQL documentation)

Clarifications:

  • The result of casting an array to text is that the resulting string starts and ends with curly braces. Those braces need to be removed by some method, if they are not desired.
  • Casting ANYARRAY to TEXT best simulates CSV output as elements that contain embedded commas are double-quoted in the output in standard CSV style. Neither array_to_string() or string_agg() (the "group_concat" function added in 9.1) quote strings with embedded commas, resulting in an incorrect number of elements in the resulting list.
  • The new 9.1 string_agg() function does NOT cast the inner results to TEXT first. So "string_agg(value_field)" would generate an error if value_field is an integer. "string_agg(value_field::text)" would be required. The array_agg() method requires only one cast after the aggregation (rather than a cast per value).

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock'

In my case right after installing the MAMP accessing mysql from the terminal was giving the same socket error. At the end all it wanted was a restart and it's working.

Making macOS Installer Packages which are Developer ID ready

A +1 to accepted answer:

Destination Selection in Installer

If domain (a.k.a destination) selection is desired between user domain and system domain then rather than trying <domains enable_anywhere="true"> use following:

<domains enable_currentUserHome="true" enable_localSystem="true"/>

enable_currentUserHome installs application app under ~/Applications/ and enable_localSystem allows the application to be installed under /Application

I've tried this in El Capitan 10.11.6 (15G1217) and it seems to be working perfectly fine in 1 dev machine and 2 different VMs I tried.

Webpack how to build production code and how to use it

You can use argv npm module (install it by running npm install argv --save) for getting params in your webpack.config.js file and as for production you use -p flag "build": "webpack -p", you can add condition in webpack.config.js file like below

plugins: [
    new webpack.DefinePlugin({
        'process.env':{
            'NODE_ENV': argv.p ? JSON.stringify('production') : JSON.stringify('development')
        }
    })
]

And thats it.

Reporting Services export to Excel with Multiple Worksheets

To late for the original asker of the question, but with SQL Server 2008 R2 this is now possible:

Set the property "Pagebreak" on the tablix or table or other element to force a new tab, and then set the property "Pagename" on both the element before the pagebreak and the element after the pagebreak. These names will appear on the tabs when the report is exported to Excel.

Read about it here: http://technet.microsoft.com/en-us/library/dd255278.aspx

Remove certain characters from a string

One issue with REPLACE will be where city names contain the district name. You can use something like.

SELECT SUBSTRING(O.Ort, LEN(C.CityName) + 2, 8000)
FROM   dbo.tblOrtsteileGeo O
       JOIN dbo.Cities C
         ON C.foo = O.foo
WHERE  O.GKZ = '06440004' 

Tools to get a pictorial function call graph of code

You can check out my bash-based C call tree generator here. It lets you specify one or more C functions for which you want caller and/or called information, or you can specify a set of functions and determine the reachability graph of function calls that connects them... I.e. tell me all the ways main(), foo(), and bar() are connected. It uses graphviz/dot for a graphing engine.

What is the PostgreSQL equivalent for ISNULL()

SELECT CASE WHEN field IS NULL THEN 'Empty' ELSE field END AS field_alias

Or more idiomatic:

SELECT coalesce(field, 'Empty') AS field_alias

C++ compile error: has initializer but incomplete type

` Please include either of these:

`#include<sstream>`

using std::istringstream; 

Check if a variable exists in a list in Bash

An alternative solution inspired by the accepted response, but that uses an inverted logic:

MODE="${1}"

echo "<${MODE}>"
[[ "${MODE}" =~ ^(preview|live|both)$ ]] && echo "OK" || echo "Uh?"

Here, the input ($MODE) must be one of the options in the regular expression ('preview', 'live', or 'both'), contrary to matching the whole options list to the user input. Of course, you do not expect the regular expression to change.

How to print a number with commas as thousands separators in JavaScript

After not finding a modern and comprehensive solution here, I have written an arrow function (without regex) to solve the formatting problem and it allows the caller to provide number of fraction digits as well as the period and thousand separator for Europe and rest of the world.

Examples:

numberFormatter(1234567890.123456) => 1,234,567,890
numberFormatter(1234567890.123456, 4) => 1,234,567,890.1235
numberFormatter(1234567890.123456, 4, '.', ',') => 1.234.567.890,1235 Europe

Here is the function written in ES6 (modern syntax):

const numberFormatter = (number, fractionDigits = 0, thousandSeperator = ',', fractionSeperator = '.') => {
    if (number!==0 && !number || !Number.isFinite(number)) return number
    const frDigits = Number.isFinite(fractionDigits)? Math.min(Math.max(fractionDigits, 0), 7) : 0
    const num = number.toFixed(frDigits).toString()

    const parts = num.split('.')
    let digits = parts[0].split('').reverse()
    let sign = ''
    if (num < 0) {sign = digits.pop()}
    let final = []
    let pos = 0

    while (digits.length > 1) {
        final.push(digits.shift())
        pos++
        if (pos % 3 === 0) {final.push(thousandSeperator)}
    }
    final.push(digits.shift())
    return `${sign}${final.reverse().join('')}${frDigits > 0 ? fractionSeperator : ''}${frDigits > 0 && parts[1] ? parts[1] : ''}`
}

It has been tested for negative, bad input and NaN cases. If the input is NaN then it simply returns it.

How to parse XML in Bash?

Check out XML2 from http://www.ofb.net/~egnor/xml2/ which converts XML to a line-oriented format.

How do I pass a list as a parameter in a stored procedure?

You can try this:

create procedure [dbo].[get_user_names]
    @user_id_list varchar(2000), -- You can use any max length

    @username varchar (30) output
    as
    select last_name+', '+first_name 
    from user_mstr
    where user_id in (Select ID from dbo.SplitString( @user_id_list, ',') )

And here is the user defined function for SplitString:

Create FUNCTION [dbo].[SplitString]
(    
      @Input NVARCHAR(MAX),
      @Character CHAR(1)
)
RETURNS @Output TABLE (
      Item NVARCHAR(1000)
)
AS
BEGIN
      DECLARE @StartIndex INT, @EndIndex INT

      SET @StartIndex = 1
      IF SUBSTRING(@Input, LEN(@Input) - 1, LEN(@Input)) <> @Character
      BEGIN
            SET @Input = @Input + @Character
      END

      WHILE CHARINDEX(@Character, @Input) > 0
      BEGIN
            SET @EndIndex = CHARINDEX(@Character, @Input)

            INSERT INTO @Output(Item)
            SELECT SUBSTRING(@Input, @StartIndex, @EndIndex - 1)

            SET @Input = SUBSTRING(@Input, @EndIndex + 1, LEN(@Input))
      END

      RETURN
END

How to cat <<EOF >> a file containing code?

I know this is a two year old question, but this is a quick answer for those searching for a 'how to'.

If you don't want to have to put quotes around anything you can simply write a block of text to a file, and escape variables you want to export as text (for instance for use in a script) and not escape one's you want to export as the value of the variable.

#!/bin/bash

FILE_NAME="test.txt"
VAR_EXAMPLE="\"string\""

cat > ${FILE_NAME} << EOF
\${VAR_EXAMPLE}=${VAR_EXAMPLE} in ${FILE_NAME}  
EOF

Will write "${VAR_EXAMPLE}="string" in test.txt" into test.txt

This can also be used to output blocks of text to the console with the same rules by omitting the file name

#!/bin/bash

VAR_EXAMPLE="\"string\""

cat << EOF
\${VAR_EXAMPLE}=${VAR_EXAMPLE} to console 
EOF

Will output "${VAR_EXAMPLE}="string" to console" to the console

How to make a boolean variable switch between true and false every time a method is invoked?

Just toggle each time it is called

this.boolValue = !this.boolValue;

How do I convert an integer to string as part of a PostgreSQL query?

You can cast an integer to a string in this way

intval::text

and so in your case

SELECT * FROM table WHERE <some integer>::text = 'string of numbers'

How to handle ETIMEDOUT error?

We could look at error object for a property code that mentions the possible system error and in cases of ETIMEDOUT where a network call fails, act accordingly.

if (err.code === 'ETIMEDOUT') {
    console.log('My dish error: ', util.inspect(err, { showHidden: true, depth: 2 }));
}

Short rot13 function - Python

I couldn't leave this question here with out a single statement using the modulo operator.

def rot13(s):
    return ''.join([chr(x.islower() and ((ord(x) - 84) % 26) + 97
                        or x.isupper() and ((ord(x) - 52) % 26) + 65
                        or ord(x))
                    for x in s])

This is not pythonic nor good practice, but it works!

>> rot13("Hello World!")
Uryyb Jbeyq!

Failed to execute 'postMessage' on 'DOMWindow': https://www.youtube.com !== http://localhost:9000

Just wishing to avoid the console error, I solved this using a similar approach to Artur's earlier answer, following these steps:

  1. Downloaded the YouTube Iframe API (from https://www.youtube.com/iframe_api) to a local yt-api.js file.
  2. Removed the code which inserted the www-widgetapi.js script.
  3. Downloaded the www-widgetapi.js script (from https://s.ytimg.com/yts/jsbin/www-widgetapi-vfl7VfO1r/www-widgetapi.js) to a local www-widgetapi.js file.
  4. Replaced the targetOrigin argument in the postMessage call which was causing the error in the console, with a "*" (indicating no preference - see https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage).
  5. Appended the modified www-widgetapi.js script to the end of the yt-api.js script.

This is not the greatest solution (patched local script to maintain, losing control of where messages are sent) but it solved my issue.

Please see the security warning about removing the targetOrigin URI stated here before using this solution - https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage

Patched yt-api.js example

How to call a JavaScript function within an HTML body

Try wrapping the createtable(); statement in a <script> tag:

<table>
        <tr>
            <th>Balance</th>
            <th>Fee</th>

        </tr>
        <script>createtable();</script>
</table>

I would avoid using document.write() and use the DOM if I were you though.

How can I disable the bootstrap hover color for links?

Mark color: #005580; as color: #005580 !important;.

It will override default bootstrap hover.

WCF gives an unsecured or incorrectly secured fault error

_x000D_
_x000D_
<wsHttpBinding>_x000D_
        <binding name="ISG_Binding_Configuration" bypassProxyOnLocal="true" useDefaultWebProxy="false" hostNameComparisonMode="WeakWildcard" sendTimeout="00:30:00" receiveTimeout="00:30:00" maxReceivedMessageSize="2147483647" maxBufferPoolSize="2147483647">_x000D_
          <readerQuotas maxArrayLength="2147483647" maxStringContentLength="2147483647" />_x000D_
          <security mode="None">_x000D_
            <message establishSecurityContext="false" clientCredentialType="UserName"/>_x000D_
          </security>_x000D_
        </binding>_x000D_
      </wsHttpBinding>
_x000D_
_x000D_
_x000D_

javascript convert int to float

JavaScript only has a Number type that stores floating point values.

There is no int.

Edit:

If you want to format the number as a string with two digits after the decimal point use:

(4).toFixed(2)

How to remove an iOS app from the App Store

To remove an app from the App Store, deselect all territories in your app's Rights and Pricing section on the App Summary page accessible from the Manage Your Applications module. Your app status will change to Developer Removed from Sale and will be removed from the App Store until you make it available again using the Rights and Pricing section.

How to call a method function from another class?

You need a reference to the class that contains the method you want to call. Let's say we have two classes, A and B. B has a method you want to call from A. Class A would look like this:

public class A
{
    B b; // A reference to B

    b = new B(); // Creating object of class B

    b.doSomething();  // Calling a method contained in class B from class A
}

B, which contains the doSomething() method would look like this:

public class B
{
    public void doSomething()
    {
        System.out.println("Look, I'm doing something in class B!");
    }
}

How do I pass multiple parameters into a function in PowerShell?

Because this is a frequent viewed question, I want to mention that a PowerShell function should use approved verbs (Verb-Noun as the function name). The verb part of the name identifies the action that the cmdlet performs. The noun part of the name identifies the entity on which the action is performed. This rule simplifies the usage of your cmdlets for advanced PowerShell users.

Also, you can specify things like whether the parameter is mandatory and the position of the parameter:

function Test-Script
{
    [CmdletBinding()]
    Param
    (
        [Parameter(Mandatory=$true, Position=0)]
        [string]$arg1,

        [Parameter(Mandatory=$true, Position=1)]
        [string]$arg2
    )

    Write-Host "`$arg1 value: $arg1"
    Write-Host "`$arg2 value: $arg2"
}

To pass the parameter to the function you can either use the position:

Test-Script "Hello" "World"

Or you specify the parameter name:

Test-Script -arg1 "Hello" -arg2 "World"

You don't use parentheses like you do when you call a function within C#.


I would recommend to always pass the parameter names when using more than one parameter, since this is more readable.

The static keyword and its various uses in C++

I'm not a C programmer so I can't give you information on the uses of static in a C program properly, but when it comes to Object Oriented programming static basically declares a variable, or a function or a class to be the same throughout the life of the program. Take for example.

class A
{
public:
    A();
    ~A();
    void somePublicMethod();
private:
    void somePrivateMethod();
};

When you instantiate this class in your Main you do something like this.

int main()
{
   A a1;
   //do something on a1
   A a2;
   //do something on a2
}

These two class instances are completely different from each other and operate independently from one another. But if you were to recreate the class A like this.

class A
{
public:
    A();
    ~A();
    void somePublicMethod();
    static int x;
private:
    void somePrivateMethod();
};

Lets go back to the main again.

int main()
{
   A a1;
   a1.x = 1;
   //do something on a1
   A a2;
   a2.x++;
   //do something on a2
}

Then a1 and a2 would share the same copy of int x whereby any operations on x in a1 would directly influence the operations of x in a2. So if I was to do this

int main()
{
   A a1;
   a1.x = 1;
   //do something on a1
   cout << a1.x << endl; //this would be 1
   A a2;
   a2.x++;
   cout << a2.x << endl; //this would be 2 
   //do something on a2
}

Both instances of the class A share static variables and functions. Hope this answers your question. My limited knowledge of C allows me to say that defining a function or variable as static means it is only visible to the file that the function or variable is defined as static in. But this would be better answered by a C guy and not me. C++ allows both C and C++ ways of declaring your variables as static because its completely backwards compatible with C.

Retrieving Data from SQL Using pyodbc

In order to receive actual data stored in the table, you should use one of fetch...() functions or use the cursor as an iterator (i.e. "for row in cursor"...). This is described in the documentation:

cursor.execute("select user_id, user_name from users where user_id < 100")
rows = cursor.fetchall()
for row in rows:
    print row.user_id, row.user_name

Using crontab to execute script every minute and another every 24 hours

This is the format of /etc/crontab:

# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name  command to be executed

I recommend copy & pasting that into the top of your crontab file so that you always have the reference handy. RedHat systems are setup that way by default.

To run something every minute:

* * * * * username /var/www/html/a.php

To run something at midnight of every day:

0 0 * * * username /var/www/html/reset.php

You can either include /usr/bin/php in the command to run, or you can make the php scripts directly executable:

chmod +x file.php

Start your php file with a shebang so that your shell knows which interpreter to use:

#!/usr/bin/php
<?php
// your code here

jQuery adding 2 numbers from input fields

There are two way that you can add two number in jQuery

First way:

var x = parseInt(a) + parseInt(b);
alert(x);

Second Way:

var x = parseInt(a+2);
alert(x);

Now come your question

var a = parseInt($("#a").val()); 
var b = parseInt($("#b").val());
alert(a+b);

Could not calculate build plan: Plugin org.apache.maven.plugins:maven-resources-plugin:2.5 or one of its dependencies could not be resolved

I am facing the same issue and none of above works, like by updating the MVN also same error, by building is also same, entered details in settings.xml though even same issue.

After that again I tried and did something different which did not did before and it works.

Its simple, I clicked the force update while updating the Mvn project. By right clicking on the pom file, there is option under Maven, "Update Project" and it open up one popup to select update option. PLEASE MAKE SURE FORCE UPDATE IS CHECKED, by default is unchecked. And bingo, that works like charm!

How to validate a date?

My function returns true if is a valid date otherwise returns false :D

_x000D_
_x000D_
function isDate  (day, month, year){_x000D_
 if(day == 0 ){_x000D_
  return false;_x000D_
 }_x000D_
 switch(month){_x000D_
  case 1: case 3: case 5: case 7: case 8: case 10: case 12:_x000D_
   if(day > 31)_x000D_
    return false;_x000D_
   return true;_x000D_
  case 2:_x000D_
   if (year % 4 == 0)_x000D_
    if(day > 29){_x000D_
     return false;_x000D_
    }_x000D_
    else{_x000D_
     return true;_x000D_
    }_x000D_
   if(day > 28){_x000D_
    return false;_x000D_
   }_x000D_
   return true;_x000D_
  case 4: case 6: case 9: case 11:_x000D_
   if(day > 30){_x000D_
    return false;_x000D_
   }_x000D_
   return true;_x000D_
  default:_x000D_
   return false;_x000D_
 }_x000D_
}_x000D_
_x000D_
console.log(isDate(30, 5, 2017));_x000D_
console.log(isDate(29, 2, 2016));_x000D_
console.log(isDate(29, 2, 2015));
_x000D_
_x000D_
_x000D_

What does "\r" do in the following script?

'\r' means 'carriage return' and it is similar to '\n' which means 'line break' or more commonly 'new line'

in the old days of typewriters, you would have to move the carriage that writes back to the start of the line, and move the line down in order to write onto the next line.

in the modern computer era we still have this functionality for multiple reasons. but mostly we use only '\n' and automatically assume that we want to start writing from the start of the line, since it would not make much sense otherwise.

however, there are some times when we want to use JUST the '\r' and that would be if i want to write something to an output, and the instead of going down to a new line and writing something else, i want to write something over what i already wrote, this is how many programs in linux or in windows command line are able to have 'progress' information that changes on the same line.

nowadays most systems use only the '\n' to denote a newline. but some systems use both together.

you can see examples of this given in some of the other answers, but the most common are:

  • windows ends lines with '\r\n'
  • mac ends lines with '\r'
  • unix/linux use '\n'

and some other programs also have specific uses for them.

for more information about the history of these characters

Turning a Comma Separated string into individual rows

Nice to see that it have been solved in the 2016 version, but for all of those that is not on that, here are two generalized and simplified versions of the methods above.

The XML-method is shorter, but of course requires the string to allow for the xml-trick (no 'bad' chars.)

XML-Method:

create function dbo.splitString(@input Varchar(max), @Splitter VarChar(99)) returns table as
Return
    SELECT Split.a.value('.', 'VARCHAR(max)') AS Data FROM
    ( SELECT CAST ('<M>' + REPLACE(@input, @Splitter, '</M><M>') + '</M>' AS XML) AS Data 
    ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a); 

Recursive method:

create function dbo.splitString(@input Varchar(max), @Splitter Varchar(99)) returns table as
Return
  with tmp (DataItem, ix) as
   ( select @input  , CHARINDEX('',@Input)  --Recu. start, ignored val to get the types right
     union all
     select Substring(@input, ix+1,ix2-ix-1), ix2
     from (Select *, CHARINDEX(@Splitter,@Input+@Splitter,ix+1) ix2 from tmp) x where ix2<>0
   ) select DataItem from tmp where ix<>0

Function in action

Create table TEST_X (A int, CSV Varchar(100));
Insert into test_x select 1, 'A,B';
Insert into test_x select 2, 'C,D';

Select A,data from TEST_X x cross apply dbo.splitString(x.CSV,',') Y;

Drop table TEST_X

XML-METHOD 2: Unicode Friendly (Addition courtesy of Max Hodges) create function dbo.splitString(@input nVarchar(max), @Splitter nVarchar(99)) returns table as Return SELECT Split.a.value('.', 'NVARCHAR(max)') AS Data FROM ( SELECT CAST ('<M>' + REPLACE(@input, @Splitter, '</M><M>') + '</M>' AS XML) AS Data ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a);

How do I open an .exe from another C++ .exe?

Provide the full path of the file openfile.exe and remember not to put forward slash / in the path such as c:/users/username/etc.... instead of that use c:\\Users\\username\etc (for windows)

May be this will help you.

SQL Server Script to create a new user

If you want to create a generic script you can do it with an Execute statement with a Replace with your username and database name

Declare @userName as varchar(50); 
Declare @defaultDataBaseName as varchar(50);
Declare @LoginCreationScript as varchar(max);
Declare @UserCreationScript as varchar(max);
Declare @TempUserCreationScript as varchar(max);
set @defaultDataBaseName = 'data1';
set @userName = 'domain\userName';
set @LoginCreationScript ='CREATE LOGIN [{userName}]
FROM WINDOWS 
WITH DEFAULT_DATABASE ={dataBaseName}'

set @UserCreationScript ='
USE {dataBaseName}
CREATE User [{userName}] for LOGIN [{userName}];
EXEC sp_addrolemember ''db_datareader'', ''{userName}'';
EXEC sp_addrolemember ''db_datawriter'', ''{userName}'';
Grant Execute on Schema :: dbo TO [{userName}];'
/*Login creation*/
set @LoginCreationScript=Replace(Replace(@LoginCreationScript, '{userName}', @userName), '{dataBaseName}', @defaultDataBaseName)
set @UserCreationScript =Replace(@UserCreationScript, '{userName}', @userName)
Execute(@LoginCreationScript)

/*User creation and role assignment*/
set @TempUserCreationScript =Replace(@UserCreationScript, '{dataBaseName}', @defaultDataBaseName)
Execute(@TempUserCreationScript)
set @TempUserCreationScript =Replace(@UserCreationScript, '{dataBaseName}', 'db2')
Execute(@TempUserCreationScript)
set @TempUserCreationScript =Replace(@UserCreationScript, '{dataBaseName}', 'db3')
Execute(@TempUserCreationScript)