Programs & Examples On #Ddos

A distributed denial of service attack (DDoS) occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers.

How can I implement rate limiting with Apache? (requests per second)

In Apache 2.4, there's a new stock module called mod_ratelimit. For emulating modem speeds, you can use mod_dialup. Though I don't see why you just couldn't use mod_ratelimit for everything.

Pandas convert dataframe to array of tuples

#try this one:

tuples = list(zip(data_set["data_date"], data_set["data_1"],data_set["data_2"]))
print (tuples)

Reflection: How to Invoke Method with parameters

I would use it like this, its way shorter and it won't give any problems

        dynamic result = null;
        if (methodInfo != null)
        {
            ParameterInfo[] parameters = methodInfo.GetParameters();
            object classInstance = Activator.CreateInstance(type, null);
            result = methodInfo.Invoke(classInstance, parameters.Length == 0 ? null : parametersArray);
        }

Combine two tables that have no common fields

This is a very strange request, and almost certainly something you'd never want to do in a real-world application, but from a purely academic standpoint it's an interesting challenge. With SQL Server 2005 you could use common table expressions and the row_number() functions and join on that:

with OrderedFoos as (
    select row_number() over (order by FooName) RowNum, *
    from Foos (nolock)
),
OrderedBars as (
    select row_number() over (order by BarName) RowNum, *
    from Bars (nolock)
)
select * 
from OrderedFoos f
    full outer join OrderedBars u on u.RowNum = f.RowNum

This works, but it's supremely silly and I offer it only as a "community wiki" answer because I really wouldn't recommend it.

"int cannot be dereferenced" in Java

id is of primitive type int and not an Object. You cannot call methods on a primitive as you are doing here :

id.equals

Try replacing this:

        if (id.equals(list[pos].getItemNumber())){ //Getting error on "equals"

with

        if (id == list[pos].getItemNumber()){ //Getting error on "equals"

Disabled UIButton not faded or grey

This question has a lot of answers but all they looks not very useful in case if you really want to use backgroundColor to style your buttons. UIButton has nice option to set different images for different control states but there is not same feature for background colors. So one of solutions is to add extension which will generate images from color and apply them to button.

extension UIButton {
  private func image(withColor color: UIColor) -> UIImage? {
    let rect = CGRect(x: 0.0, y: 0.0, width: 1.0, height: 1.0)
    UIGraphicsBeginImageContext(rect.size)
    let context = UIGraphicsGetCurrentContext()

    context?.setFillColor(color.cgColor)
    context?.fill(rect)

    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return image
  }

  func setBackgroundColor(_ color: UIColor, for state: UIControlState) {
    self.setBackgroundImage(image(withColor: color), for: state)
  }
}

Only one issue with this solution -- this change won't be applied to buttons created in storyboard. As for me it's not an issue because I prefer to style UI from code. If you want to use storyboards then some additional magic with @IBInspectable needed.

Second option is subclassing but I prefer to avoid this.

POST: sending a post request in a url itself

Based on what you provided, it is pretty simple for what you need to do and you even have a number of ways to go about doing it. You'll need something that'll let you post a body with your request. Almost any programming language can do this as well as command line tools like cURL.

One you have your tool decided, you'll need to create your JSON body and submit it to the server.

An example using cURL would be (all in one line, minus the \ at the end of the first line):

curl -v -H "Content-Type: application/json" -X POST \
     -d '{"name":"your name","phonenumber":"111-111"}' http://www.abc.com/details

The above command will create a request that should look like the following:

POST /details HTTP/1.1
Host: www.abc.com
Content-Type: application/json
Content-Length: 44

{"name":"your name","phonenumber":"111-111"}

Auto-scaling input[type=text] to width of value?

Here is my modification of nrabinowitz' solution. I didn't use the size property, because it's not perfect with proportional fonts as @Mark noted. My solution place an element after your input and gets width counted by browser (using jQuery).

Although I don't test it, I suppose it will work only if all CSS properties affecting font are inherited.

The input width changes on focusout event, which works better for me. But you can use keyup/keypress to change input's width when typing as well.

function resizeInput() {

    //Firstly take the content or placeholder if content is missing.
    var content =
        $(this).val().length > 0 ? $(this).val() : $(this).prop("placeholder");

    //Create testing element with same content as input.
    var widthTester = $("<span>"+content+"</span>").hide();

    //Place testing element into DOM after input (so it inherits same formatting as input does).
    widthTester.insertAfter($(this));

    //Set inputs width; you may want to use outerWidth() or innerWidth()
    //depending whether you want to count padding and border or not.
    $(this).css("width",widthTester.width()+"px");

    //Remove the element from the DOM
    widthTester.remove();
 }

 $('.resizing-input').focusout(resizeInput).each(resizeInput);

Pad with leading zeros

An integer value is a mathematical representation of a number and is ignorant of leading zeroes.

You can get a string with leading zeroes like this:

someNumber.ToString("00000000")

SQL update fields of one table from fields of another one

I have been working with IBM DB2 database for more then decade and now trying to learn PostgreSQL.

It works on PostgreSQL 9.3.4, but does not work on DB2 10.5:

UPDATE B SET
     COLUMN1 = A.COLUMN1,
     COLUMN2 = A.COLUMN2,
     COLUMN3 = A.COLUMN3
FROM A
WHERE A.ID = B.ID

Note: Main problem is FROM cause that is not supported in DB2 and also not in ANSI SQL.

It works on DB2 10.5, but does NOT work on PostgreSQL 9.3.4:

UPDATE B SET
    (COLUMN1, COLUMN2, COLUMN3) =
               (SELECT COLUMN1, COLUMN2, COLUMN3 FROM A WHERE ID = B.ID)

FINALLY! It works on both PostgreSQL 9.3.4 and DB2 10.5:

UPDATE B SET
     COLUMN1 = (SELECT COLUMN1 FROM A WHERE ID = B.ID),
     COLUMN2 = (SELECT COLUMN2 FROM A WHERE ID = B.ID),
     COLUMN3 = (SELECT COLUMN3 FROM A WHERE ID = B.ID)

Batch script loop

Here is a template script I will use.

@echo off
goto Loop

:Loop
<EXTRA SCRIPTING HERE!!!!>
goto Loop

exit

What this does is when it starts it turns off echo then after that it runs the "Loop" but in that place it keeps going to "Loop" (I hope this helps.)

How do I set a Windows scheduled task to run in the background?

As noted by Mattias Nordqvist in the comments below, you can also select the radio button option "Run whether user is logged on or not". When saving the task, you will be prompted once for the user password. bambams noted that this wouldn't grant System permissions to the process, and also seems to hide the command window.


It's not an obvious solution, but to make a Scheduled Task run in the background, change the User running the task to "SYSTEM", and nothing will appear on your screen.

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SQLAlchemy: What's the difference between flush() and commit()?

This does not strictly answer the original question but some people have mentioned that with session.autoflush = True you don't have to use session.flush()... And this is not always true.

If you want to use the id of a newly created object in the middle of a transaction, you must call session.flush().

# Given a model with at least this id
class AModel(Base):
   id = Column(Integer, primary_key=True)  # autoincrement by default on integer primary key

session.autoflush = True

a = AModel()
session.add(a)
a.id  # None
session.flush()
a.id  # autoincremented integer

This is because autoflush does NOT auto fill the id (although a query of the object will, which sometimes can cause confusion as in "why this works here but not there?" But snapshoe already covered this part).


One related aspect that seems pretty important to me and wasn't really mentioned:

Why would you not commit all the time? - The answer is atomicity.

A fancy word to say: an ensemble of operations have to all be executed successfully OR none of them will take effect.

For example, if you want to create/update/delete some object (A) and then create/update/delete another (B), but if (B) fails you want to revert (A). This means those 2 operations are atomic.

Therefore, if (B) needs a result of (A), you want to call flush after (A) and commit after (B).

Also, if session.autoflush is True, except for the case that I mentioned above or others in Jimbo's answer, you will not need to call flush manually.

How to set the From email address for mailx command?

On debian where bsd-mailx is installed by default, the -r option does not work. However you can use mailx -s subject [email protected] -- -f [email protected] instead. According to man page, you can specify sendmail options after --.

Is it possible to animate scrollTop with jQuery?

$(".scroll-top").on("click", function(e){
   e.preventDefault();
   $("html, body").animate({scrollTop:"0"},600);
});

.htaccess redirect www to non-www with SSL/HTTPS

www to non www with https

RewriteEngine on

RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ https://%1/$1 [R=301,L]

RewriteCond %{ENV:HTTPS} !on
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

Instantiating a generic class in Java

Here's a rather contrived way to do it without explicitly using an constructor argument. You need to extend a parameterized abstract class.

public class Test {   
    public static void main(String [] args) throws Exception {
        Generic g = new Generic();
        g.initParameter();
    }
}

import java.lang.reflect.ParameterizedType;
public abstract class GenericAbstract<T extends Foo> {
    protected T parameter;

    @SuppressWarnings("unchecked")
    void initParameter() throws Exception, ClassNotFoundException, 
        InstantiationException {
        // Get the class name of this instance's type.
        ParameterizedType pt
            = (ParameterizedType) getClass().getGenericSuperclass();
        // You may need this split or not, use logging to check
        String parameterClassName
            = pt.getActualTypeArguments()[0].toString().split("\\s")[1];
        // Instantiate the Parameter and initialize it.
        parameter = (T) Class.forName(parameterClassName).newInstance();
    }
}

public class Generic extends GenericAbstract<Foo> {
}

public class Foo {
    public Foo() {
        System.out.println("Foo constructor...");
    }
}

How to make html <select> element look like "disabled", but pass values?

Wow, I had the same problem, but a line of code resolved my problem. I wrote

$last_child_topic.find( "*" ).prop( "disabled", true );
$last_child_topic.find( "option" ).prop( "disabled", false );   //This seems to work on mine

I send the form to a php script then it prints the correct value for each options while it was "null" before.

Tell me if this works out. I wonder if this only works on mine somehow.

What is the meaning of curly braces?

In Python, curly braces are used to define a dictionary.

a={'one':1, 'two':2, 'three':3}
a['one']=1
a['three']=3

In other languages, { } are used as part of the flow control. Python however used indentation as its flow control because of its focus on readable code.

for entry in entries:
     code....

There's a little easter egg in Python when it comes to braces. Try running this on the Python Shell and enjoy.

from __future__ import braces

Correct way to work with vector of arrays

You cannot store arrays in a vector or any other container. The type of the elements to be stored in a container (called the container's value type) must be both copy constructible and assignable. Arrays are neither.

You can, however, use an array class template, like the one provided by Boost, TR1, and C++0x:

std::vector<std::array<double, 4> >

(You'll want to replace std::array with std::tr1::array to use the template included in C++ TR1, or boost::array to use the template from the Boost libraries. Alternatively, you can write your own; it's quite straightforward.)

What's the difference between "Layers" and "Tiers"?

When you talk about presentation, service, data, network layer, you are talking about layers. When you "deploy them separately", you talk about tiers.

Tiers is all about deployment. Take it this way: We have an application which has a frontend created in Angular, it has a backend as MongoDB and a middle layer which interacts between the frontend and the backend. So, when this frontend application, database application, and the middle layer is all deployed separately, we say it's a 3 tier application.

Benefit: If we need to scale our backend in the future, we only need to scale the backend independently and there's no need to scale up the frontend.

How do I delete a local repository in git?

Delete the .git directory in the root-directory of your repository if you only want to delete the git-related information (branches, versions).

If you want to delete everything (git-data, code, etc), just delete the whole directory.

.git directories are hidden by default, so you'll need to be able to view hidden files to delete it.

Always pass weak reference of self into block in ARC?

I totally agree with @jemmons:

But this should not be the default pattern you follow when dealing with blocks that call self! This should only be used to break what would otherwise be a retain cycle between self and the block. If you were to adopt this pattern everywhere, you'd run the risk of passing a block to something that got executed after self was deallocated.

//SUSPICIOUS EXAMPLE:
__weak MyObject *weakSelf = self;
[[SomeOtherObject alloc] initWithCompletion:^{
  //By the time this gets called, "weakSelf" might be nil because it's not  retained!
  [weakSelf doSomething];
}];

To overcome this problem one can define a strong reference over the weakSelf inside the block:

__weak MyObject *weakSelf = self;
[[SomeOtherObject alloc] initWithCompletion:^{
  MyObject *strongSelf = weakSelf;
  [strongSelf doSomething];
}];

Checkout Jenkins Pipeline Git SCM with credentials?

Adding you a quick example using git plugin GitSCM:

    checkout([
        $class: 'GitSCM', 
        branches: [[name: '*/master']], 
        doGenerateSubmoduleConfigurations: false, 
        extensions: [[$class: 'CleanCheckout']], 
        submoduleCfg: [], 
        userRemoteConfigs: [[credentialsId: '<gitCredentials>', url: '<gitRepoURL>']]
    ])

in your pipeline

stage('checkout'){
    steps{
        script{
            checkout
        }
    }
}

How to uninstall Apache with command line

On Windows 8.1 I had to run cmd.exe as administrator (even though I was logged in as admin). Otherwise I got an error when trying to execute: httpd.exe -k uninstall

Error: C:\Program Files\Apache\bin>(OS 5)Access is denied. : AH00373: Apache2.4: OpenS ervice failed

How to detect IE11?

Get IE Version from the User-Agent

var ie = 0;
try { ie = navigator.userAgent.match( /(MSIE |Trident.*rv[ :])([0-9]+)/ )[ 2 ]; }
catch(e){}

How it works: The user-agent string for all IE versions includes a portion "MSIE space version" or "Trident other-text rv space-or-colon version". Knowing this, we grab the version number from a String.match() regular expression. A try-catch block is used to shorten the code, otherwise we'd need to test the array bounds for non-IE browsers.

Note: The user-agent can be spoofed or omitted, sometimes unintentionally if the user has set their browser to a "compatibility mode". Though this doesn't seem like much of an issue in practice.


Get IE Version without the User-Agent

var d = document, w = window;
var ie = ( !!w.MSInputMethodContext ? 11 : !d.all ? 99 : w.atob ? 10 : 
d.addEventListener ? 9 : d.querySelector ? 8 : w.XMLHttpRequest ? 7 : 
d.compatMode ? 6 : w.attachEvent ? 5 : 1 );

How it works: Each version of IE adds support for additional features not found in previous versions. So we can test for the features in a top-down manner. A ternary sequence is used here for brevity, though if-then and switch statements would work just as well. The variable ie is set to an integer 5-11, or 1 for older, or 99 for newer/non-IE. You can set it to 0 if you just want to test for IE 1-11 exactly.

Note: Object detection may break if your code is run on a page with third-party scripts that add polyfills for things like document.addEventListener. In such situations the user-agent is the best option.


Detect if the Browser is Modern

If you're only interested in whether or not a browser supports most HTML 5 and CSS 3 standards, you can reasonably assume that IE 8 and lower remain the primary problem apps. Testing for window.getComputedStyle will give you a fairly good mix of modern browsers, as well (IE 9, FF 4, Chrome 11, Safari 5, Opera 11.5). IE 9 greatly improves on standards support, but native CSS animation requires IE 10.

var isModernBrowser = ( !document.all || ( document.all && document.addEventListener ) ); 

Convert Python dict into a dataframe

The error here, is since calling the DataFrame constructor with scalar values (where it expects values to be a list/dict/... i.e. have multiple columns):

pd.DataFrame(d)
ValueError: If using all scalar values, you must must pass an index

You could take the items from the dictionary (i.e. the key-value pairs):

In [11]: pd.DataFrame(d.items())  # or list(d.items()) in python 3
Out[11]:
             0    1
0   2012-07-02  392
1   2012-07-06  392
2   2012-06-29  391
3   2012-06-28  391
...

In [12]: pd.DataFrame(d.items(), columns=['Date', 'DateValue'])
Out[12]:
          Date  DateValue
0   2012-07-02        392
1   2012-07-06        392
2   2012-06-29        391

But I think it makes more sense to pass the Series constructor:

In [21]: s = pd.Series(d, name='DateValue')
Out[21]:
2012-06-08    388
2012-06-09    388
2012-06-10    388

In [22]: s.index.name = 'Date'

In [23]: s.reset_index()
Out[23]:
          Date  DateValue
0   2012-06-08        388
1   2012-06-09        388
2   2012-06-10        388

How to put attributes via XElement

Add XAttribute in the constructor of the XElement, like

new XElement("Conn", new XAttribute("Server", comboBox1.Text));

You can also add multiple attributes or elements via the constructor

new XElement("Conn", new XAttribute("Server", comboBox1.Text), new XAttribute("Database", combobox2.Text));

or you can use the Add-Method of the XElement to add attributes

XElement element = new XElement("Conn");
XAttribute attribute = new XAttribute("Server", comboBox1.Text);
element.Add(attribute);

log4j:WARN No appenders could be found for logger in web.xml

If that's the entire log4j.properties file it looks like you're never actually creating a logger. You need a line like:

log4j.rootLogger=debug,A1

Excel "External table is not in the expected format."

ACE has Superceded JET

Ace Supports all Previous versions of Office

This Code works well!

        OleDbConnection MyConnection;
        DataSet DtSet;
        OleDbDataAdapter MyCommand;
        
        MyConnection = new System.Data.OleDb.OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=..\\Book.xlsx;Extended Properties=Excel 12.0;");
        MyCommand = new System.Data.OleDb.OleDbDataAdapter("select * from [Sheet1$]", MyConnection);
        DtSet = new System.Data.DataSet();
        
        MyCommand.Fill(DtSet);
        dataGridView1.DataSource = DtSet.Tables[0];
        MyConnection.Close();

Installing Java 7 (Oracle) in Debian via apt-get

Managed to get answer after do some google..

echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list
echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
apt-get update
# Java 7
apt-get install oracle-java7-installer
# For Java 8 command is:
apt-get install oracle-java8-installer

Convert list of dictionaries to a pandas DataFrame

Supposing d is your list of dicts, simply:

df = pd.DataFrame(d)

Note: this does not work with nested data.

ruby 1.9: invalid byte sequence in UTF-8

Before you use scan, make sure that the requested page's Content-Type header is text/html, since there can be links to things like images which are not encoded in UTF-8. The page could also be non-html if you picked up a href in something like a <link> element. How to check this varies on what HTTP library you are using. Then, make sure the result is only ascii with String#ascii_only? (not UTF-8 because HTML is only supposed to be using ascii, entities can be used otherwise). If both of those tests pass, it is safe to use scan.

What is the difference between a strongly typed language and a statically typed language?

This is often misunderstood so let me clear it up.

Static/Dynamic Typing

Static typing is where the type is bound to the variable. Types are checked at compile time.

Dynamic typing is where the type is bound to the value. Types are checked at run time.

So in Java for example:

String s = "abcd";

s will "forever" be a String. During its life it may point to different Strings (since s is a reference in Java). It may have a null value but it will never refer to an Integer or a List. That's static typing.

In PHP:

$s = "abcd";          // $s is a string
$s = 123;             // $s is now an integer
$s = array(1, 2, 3);  // $s is now an array
$s = new DOMDocument; // $s is an instance of the DOMDocument class

That's dynamic typing.

Strong/Weak Typing

(Edit alert!)

Strong typing is a phrase with no widely agreed upon meaning. Most programmers who use this term to mean something other than static typing use it to imply that there is a type discipline that is enforced by the compiler. For example, CLU has a strong type system that does not allow client code to create a value of abstract type except by using the constructors provided by the type. C has a somewhat strong type system, but it can be "subverted" to a degree because a program can always cast a value of one pointer type to a value of another pointer type. So for example, in C you can take a value returned by malloc() and cheerfully cast it to FILE*, and the compiler won't try to stop you—or even warn you that you are doing anything dodgy.

(The original answer said something about a value "not changing type at run time". I have known many language designers and compiler writers and have not known one that talked about values changing type at run time, except possibly some very advanced research in type systems, where this is known as the "strong update problem".)

Weak typing implies that the compiler does not enforce a typing discpline, or perhaps that enforcement can easily be subverted.

The original of this answer conflated weak typing with implicit conversion (sometimes also called "implicit promotion"). For example, in Java:

String s = "abc" + 123; // "abc123";

This is code is an example of implicit promotion: 123 is implicitly converted to a string before being concatenated with "abc". It can be argued the Java compiler rewrites that code as:

String s = "abc" + new Integer(123).toString();

Consider a classic PHP "starts with" problem:

if (strpos('abcdef', 'abc') == false) {
  // not found
}

The error here is that strpos() returns the index of the match, being 0. 0 is coerced into boolean false and thus the condition is actually true. The solution is to use === instead of == to avoid implicit conversion.

This example illustrates how a combination of implicit conversion and dynamic typing can lead programmers astray.

Compare that to Ruby:

val = "abc" + 123

which is a runtime error because in Ruby the object 123 is not implicitly converted just because it happens to be passed to a + method. In Ruby the programmer must make the conversion explicit:

val = "abc" + 123.to_s

Comparing PHP and Ruby is a good illustration here. Both are dynamically typed languages but PHP has lots of implicit conversions and Ruby (perhaps surprisingly if you're unfamiliar with it) doesn't.

Static/Dynamic vs Strong/Weak

The point here is that the static/dynamic axis is independent of the strong/weak axis. People confuse them probably in part because strong vs weak typing is not only less clearly defined, there is no real consensus on exactly what is meant by strong and weak. For this reason strong/weak typing is far more of a shade of grey rather than black or white.

So to answer your question: another way to look at this that's mostly correct is to say that static typing is compile-time type safety and strong typing is runtime type safety.

The reason for this is that variables in a statically typed language have a type that must be declared and can be checked at compile time. A strongly-typed language has values that have a type at run time, and it's difficult for the programmer to subvert the type system without a dynamic check.

But it's important to understand that a language can be Static/Strong, Static/Weak, Dynamic/Strong or Dynamic/Weak.

Modifying a file inside a jar

You can use Vim:

vim my.jar

Vim is able to edit compressed text files, given you have unzip in your environment.

What does %s and %d mean in printf in the C language?

"%s%d%s%d\n" is the format string; it tells the printf function how to format and display the output. Anything in the format string that doesn't have a % immediately in front of it is displayed as is.

%s and %d are conversion specifiers; they tell printf how to interpret the remaining arguments. %s tells printf that the corresponding argument is to be treated as a string (in C terms, a 0-terminated sequence of char); the type of the corresponding argument must be char *. %d tells printf that the corresponding argument is to be treated as an integer value; the type of the corresponding argument must be int. Since you're coming from a Java background, it's important to note that printf (like other variadic functions) is relying on you to tell it what the types of the remaining arguments are. If the format string were "%d%s%d%s\n", printf would attempt to treat "Length of string" as an integer value and i as a string, with tragic results.

Five equal columns in twitter bootstrap

Bootstrap 4, variable number of columns per row

If you want to have up to five columns per row, so that fewer numbers of columns still only take up 1/5th of the row each, the solution is to use Bootstrap 4's mixins:

SCSS:

.col-2-4 {
    @include make-col-ready(); // apply standard column margins, padding, etc.
    @include make-col(2.4); // 12/5 = 2.4
}
.col-sm-2-4 {
    @include make-col-ready();
    @include media-breakpoint-up(sm) {
        @include make-col(2.4);
    }
}
.col-md-2-4 {
    @include make-col-ready();
    @include media-breakpoint-up(md) {
        @include make-col(2.4);
    }
}
.col-lg-2-4 {
    @include make-col-ready();
    @include media-breakpoint-up(lg) {
        @include make-col(2.4);
    }
}
.col-xl-2-4 {
    @include make-col-ready();
    @include media-breakpoint-up(xl) {
        @include make-col(2.4);
    }
}

HTML:

<div class="container">    
  <div class="row">
    <div class="col-12 col-sm-2-4">1 of 5</div>
    <div class="col-12 col-sm-2-4">2 of 5</div>
    <div class="col-12 col-sm-2-4">3 of 5</div>
    <div class="col-12 col-sm-2-4">4 of 5</div>
    <div class="col-12 col-sm-2-4">5 of 5</div>
  </div>
  <div class="row">
    <div class="col-12 col-sm-2-4">1 of 2</div> <!-- same width as column "1 of 5" above -->
    <div class="col-12 col-sm-2-4">2 of 2</div> <!-- same width as column "2 of 5" above -->
  </div>
</div>

How to return a value from try, catch, and finally?

It is because you are in a try statement. Since there could be an error, sum might not get initialized, so put your return statement in the finally block, that way it will for sure be returned.

Make sure that you initialize sum outside the try/catch/finally so that it is in scope.

Click a button programmatically

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Button2_Click(Sender, e)
End Sub

This Code call button click event programmatically

Defined Edges With CSS3 Filter Blur

Insert the image inside a with position: relative; and overflow: hidden;

HTML

<div><img src="#"></div>

CSS

div {
    position: relative;
    overflow: hidden;
}
img {
    filter: blur(5px);
        -webkit-filter: blur(5px);
        -moz-filter: blur(5px);
        -o-filter: blur(5px);
        -ms-filter: blur(5px);
}

This also works on variable sizes elements, like dynamic div's.

How to use 'cp' command to exclude a specific directory?

I assume you're using bash or dash. Would this work?

shopt -s extglob  # sets extended pattern matching options in the bash shell
cp $(ls -laR !(subdir/file1|file2|subdir2/file3)) destination

Doing an ls excluding the files you don't want, and using that as the first argument for cp

Calling C++ class methods via a function pointer

Reason why you cannot use function pointers to call member functions is that ordinary function pointers are usually just the memory address of the function.

To call a member function, you need to know two things:

  • Which member function to call
  • Which instance should be used (whose member function)

Ordinary function pointers cannot store both. C++ member function pointers are used to store a), which is why you need to specify the instance explicitly when calling a member function pointer.

Including a css file in a blade template?

As you said this is a very bad way to do so laravel doesn't have that functionality AFAIK.

However blade can run plain php so you can do like this if you really need to:

<?php include public_path('css/styles.css') ?>

What is dtype('O'), in pandas?

It means:

'O'     (Python) objects

Source.

The first character specifies the kind of data and the remaining characters specify the number of bytes per item, except for Unicode, where it is interpreted as the number of characters. The item size must correspond to an existing type, or an error will be raised. The supported kinds are to an existing type, or an error will be raised. The supported kinds are:

'b'       boolean
'i'       (signed) integer
'u'       unsigned integer
'f'       floating-point
'c'       complex-floating point
'O'       (Python) objects
'S', 'a'  (byte-)string
'U'       Unicode
'V'       raw data (void)

Another answer helps if need check types.

What is the purpose of the var keyword and when should I use it (or omit it)?

Here's quite a good example of how you can get caught out from not declaring local variables with var:

<script>
one();

function one()
{
    for (i = 0;i < 10;i++)
    {
        two();
        alert(i);
    }
}

function two()
{
    i = 1;
}
</script>

(i is reset at every iteration of the loop, as it's not declared locally in the for loop but globally) eventually resulting in infinite loop

Global variables in c#.net

/// <summary>
/// Contains global variables for project.
/// </summary>
public static class GlobalVar
{
/// <summary>
/// Global variable that is constant.
/// </summary>
public const string GlobalString = "Important Text";

/// <summary>
/// Static value protected by access routine.
/// </summary>
static int _globalValue;

/// <summary>
/// Access routine for global variable.
/// </summary>
public static int GlobalValue
{
get
{
    return _globalValue;
}
set
{
    _globalValue = value;
}
}

/// <summary>
/// Global static field.
/// </summary>
public static bool GlobalBoolean;
}

Create a hidden field in JavaScript

You can use this method to create hidden text field with/without form. If you need form just pass form with object status = true.

You can also add multiple hidden fields. Use this way:

CustomizePPT.setHiddenFields( 
    { 
        "hidden" : 
        {
            'fieldinFORM' : 'thisdata201' , 
            'fieldinFORM2' : 'this3' //multiple hidden fields
            .
            .
            .
            .
            .
            'nNoOfFields' : 'nthData'
        },
    "form" : 
    {
        "status" : "true",
        "formID" : "form3"
    } 
} );

_x000D_
_x000D_
var CustomizePPT = new Object();_x000D_
CustomizePPT.setHiddenFields = function(){ _x000D_
    var request = [];_x000D_
 var container = '';_x000D_
 console.log(arguments);_x000D_
 request = arguments[0].hidden;_x000D_
    console.log(arguments[0].hasOwnProperty('form'));_x000D_
 if(arguments[0].hasOwnProperty('form') == true)_x000D_
 {_x000D_
  if(arguments[0].form.status == 'true'){_x000D_
   var parent = document.getElementById("container");_x000D_
   container = document.createElement('form');_x000D_
   parent.appendChild(container);_x000D_
   Object.assign(container, {'id':arguments[0].form.formID});_x000D_
  }_x000D_
 }_x000D_
 else{_x000D_
   container = document.getElementById("container");_x000D_
 }_x000D_
 _x000D_
 //var container = document.getElementById("container");_x000D_
 Object.keys(request).forEach(function(elem)_x000D_
 {_x000D_
  if($('#'+elem).length <= 0){_x000D_
   console.log("Hidden Field created");_x000D_
   var input = document.createElement('input');_x000D_
   Object.assign(input, {"type" : "text", "id" : elem, "value" : request[elem]});_x000D_
   container.appendChild(input);_x000D_
  }else{_x000D_
   console.log("Hidden Field Exists and value is below" );_x000D_
   $('#'+elem).val(request[elem]);_x000D_
  }_x000D_
 });_x000D_
};_x000D_
_x000D_
CustomizePPT.setHiddenFields( { "hidden" : {'fieldinFORM' : 'thisdata201' , 'fieldinFORM2' : 'this3'}, "form" : {"status" : "true","formID" : "form3"} } );_x000D_
CustomizePPT.setHiddenFields( { "hidden" : {'withoutFORM' : 'thisdata201','withoutFORM2' : 'this2'}});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<div id='container'>_x000D_
_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to find EOF through fscanf?

If you have integers in your file fscanf returns 1 until integer occurs. For example:

FILE *in = fopen("./task.in", "r");
int length = 0;
int counter;
int sequence;

for ( int i = 0; i < 10; i++ ) {
    counter = fscanf(in, "%d", &sequence);
    if ( counter == 1 ) {
        length += 1;
    }
}

To find out the end of the file with symbols you can use EOF. For example:

char symbol;
FILE *in = fopen("./task.in", "r");

for ( ; fscanf(in, "%c", &symbol) != EOF; ) {
    printf("%c", symbol); 
}

What is the mouse down selector in CSS?

I figured out that this behaves like a mousedown event:

button:active:hover {}

How to exit a function in bash

Use return operator:

function FUNCT {
  if [ blah is false ]; then
    return 1 # or return 0, or even you can omit the argument.
  else
    keep running the function
  fi
}

Project Links do not work on Wamp Server

You can follow all steps by @RiggsFolly thats is really good answer, If you do not want to create virtual host and want to use like previous localhost/example/ or something like that you can use answer by @Arunu

But if you still face problem please use this method,

  1. Locate your wamp folder (Eg. c:/Wamp/) where you have installed
  2. Goto Wamp/www/
  3. Open index.php file
  4. find this code $projectContents .= '<li><a href="'.($suppress_localhost ? 'http://' : '').$file.'">'.$file.'</a></li>';
  5. modify it add localhost after http:// $projectContents .= '<li><a href="'.($suppress_localhost ? 'http://localhost' : '').$file.'">'.$file.'</a></li>';
  6. Restart wamp server
  7. open localhost see the updated links

Hope you got your url like previous version of wamp server.

How do I print the content of a .txt file in Python?

print ''.join(file('example.txt'))

How to convert flat raw disk image to vmdk for virtualbox or vmplayer?

First, install QEMU. On Debian-based distributions like Ubuntu, run:

$ apt-get install qemu

Then run the following command:

$ qemu-img convert -O vmdk imagefile.dd vmdkname.vmdk

I’m assuming a flat disk image is a dd-style image. The convert operation also handles numerous other formats.

For more information about the qemu-img command, see the output of

$ qemu-img -h

MySQL - Make an existing Field Unique

This code is to solve our problem to set unique key for existing table

alter ignore table ioni_groups add unique (group_name);

How to get the value from the GET parameters?

Here is the angularJs source code for parsing url query parameters into an Object :

_x000D_
_x000D_
function tryDecodeURIComponent(value) {_x000D_
  try {_x000D_
    return decodeURIComponent(value);_x000D_
  } catch (e) {_x000D_
    // Ignore any invalid uri component_x000D_
  }_x000D_
}_x000D_
_x000D_
function isDefined(value) {return typeof value !== 'undefined';}_x000D_
_x000D_
function parseKeyValue(keyValue) {_x000D_
  keyValue = keyValue.replace(/^\?/, '');_x000D_
  var obj = {}, key_value, key;_x000D_
  var iter = (keyValue || "").split('&');_x000D_
  for (var i=0; i<iter.length; i++) {_x000D_
    var kValue = iter[i];_x000D_
    if (kValue) {_x000D_
      key_value = kValue.replace(/\+/g,'%20').split('=');_x000D_
      key = tryDecodeURIComponent(key_value[0]);_x000D_
      if (isDefined(key)) {_x000D_
        var val = isDefined(key_value[1]) ? tryDecodeURIComponent(key_value[1]) : true;_x000D_
        if (!hasOwnProperty.call(obj, key)) {_x000D_
          obj[key] = val;_x000D_
        } else if (isArray(obj[key])) {_x000D_
          obj[key].push(val);_x000D_
        } else {_x000D_
          obj[key] = [obj[key],val];_x000D_
        }_x000D_
      }_x000D_
    }_x000D_
  };_x000D_
  return obj;_x000D_
}_x000D_
_x000D_
alert(JSON.stringify(parseKeyValue('?a=1&b=3&c=m2-m3-m4-m5')));
_x000D_
_x000D_
_x000D_

You can add this function to window.location:

window.location.query = function query(arg){
  q = parseKeyValue(this.search);
  if (!isDefined(arg)) {
    return q;
  }      
  if (q.hasOwnProperty(arg)) {
    return q[arg];
  } else {
    return "";
  }
}

// assuming you have this url :
// http://www.test.com/t.html?a=1&b=3&c=m2-m3-m4-m5

console.log(window.location.query())

// Object {a: "1", b: "3", c: "m2-m3-m4-m5"}

console.log(window.location.query('c'))

// "m2-m3-m4-m5"

Disable XML validation in Eclipse

Window > Preferences > Validation > uncheck XML Validator Manual and Build enter image description here

Simple Popup by using Angular JS

If you are using bootstrap.js then the below code might be useful. This is very simple. Dont have to write anything in js to invoke the pop-up.

Source :http://www.w3schools.com/bootstrap/tryit.asp?filename=trybs_modal&stacked=h

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap Example</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
  <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
</head>
<body>

<div class="container">
  <h2>Modal Example</h2>
  <!-- Trigger the modal with a button -->
  <button type="button" class="btn btn-info btn-lg" data-toggle="modal" data-target="#myModal">Open Modal</button>

  <!-- Modal -->
  <div class="modal fade" id="myModal" role="dialog">
    <div class="modal-dialog">

      <!-- Modal content-->
      <div class="modal-content">
        <div class="modal-header">
          <button type="button" class="close" data-dismiss="modal">&times;</button>
          <h4 class="modal-title">Modal Header</h4>
        </div>
        <div class="modal-body">
          <p>Some text in the modal.</p>
        </div>
        <div class="modal-footer">
          <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        </div>
      </div>

    </div>
  </div>

</div>

</body>
</html>

Single Result from Database by using mySQLi

If you assume just one result you could do this as in Edwin suggested by using specific users id.

$someUserId = 'abc123';

$stmt = $mysqli->prepare("SELECT ssfullname, ssemail FROM userss WHERE user_id = ?");
$stmt->bind_param('s', $someUserId);

$stmt->execute();

$stmt->bind_result($ssfullname, $ssemail);
$stmt->store_result();
$stmt->fetch();

ChromePhp::log($ssfullname, $ssemail); //log result in chrome if ChromePhp is used.

OR as "Your Common Sense" which selects just one user.

$stmt = $mysqli->prepare("SELECT ssfullname, ssemail FROM userss ORDER BY ssid LIMIT 1");

$stmt->execute();
$stmt->bind_result($ssfullname, $ssemail);
$stmt->store_result();
$stmt->fetch();

Nothing really different from the above except for PHP v.5

Python unittest - opposite of assertRaises?

Hi - I want to write a test to establish that an Exception is not raised in a given circumstance.

That's the default assumption -- exceptions are not raised.

If you say nothing else, that's assumed in every single test.

You don't have to actually write an any assertion for that.

How can I check which version of Angular I'm using?

In the browser's developer console (press F12 to open it), you can type the following,

angular.version.full

it will give you the full version, e.g. (depending on your current version). [It actually gets the full property of angular.version object.]

"1.4.3"

So, to see the full object, if you type

angular.version

It will give you the full version object containing version information like full, major, minor and also the codeName, e.g.

Object {full: "1.4.3", major: 1, minor: 4, dot: 3, codeName: "foam-acceleration"}

Notice: Trying to get property of non-object error

This is because $pjs is an one-element-array of objects, so first you should access the array element, which is an object and then access its attributes.

echo $pjs[0]->player_name;

Actually dump result that you pasted tells it very clearly.

How do I filter date range in DataTables?

Here is my solution, there is no way to use momemt.js.Here is DataTable with Two DatePickers for DateRange (To and From) Filter.

$.fn.dataTable.ext.search.push(
  function (settings, data, dataIndex) {
    var min = $('#min').datepicker("getDate");
    var max = $('#max').datepicker("getDate");
    var startDate = new Date(data[4]);
    if (min == null && max == null) { return true; }
    if (min == null && startDate <= max) { return true; }
    if (max == null && startDate >= min) { return true; }
    if (startDate <= max && startDate >= min) { return true; }
    return false;
  }
);
  

    

How to clone an InputStream?

Below is the solution with Kotlin.

You can copy your InputStream into ByteArray

val inputStream = ...

val byteOutputStream = ByteArrayOutputStream()
inputStream.use { input ->
    byteOutputStream.use { output ->
        input.copyTo(output)
    }
}

val byteInputStream = ByteArrayInputStream(byteOutputStream.toByteArray())

If you need to read the byteInputStream multiple times, call byteInputStream.reset() before reading again.

https://code.luasoftware.com/tutorials/kotlin/how-to-clone-inputstream/

Compiling a C++ program with gcc

use g++ instead of gcc.

Flutter: Trying to bottom-center an item in a Column, but it keeps left-aligning

Align is the way to go is you have only one child.

If you have more, consider doing something like this :

return new Column(
  crossAxisAlignment: CrossAxisAlignment.center,
  mainAxisSize: MainAxisSize.max,
  mainAxisAlignment: MainAxisAlignment.end,
  children: <Widget>[
      //your elements here
  ],
);

Java getting the Enum name given the Enum Value

Here is the below code, it will return the Enum name from Enum value.

public enum Test {

    PLUS("Plus One"), MINUS("MinusTwo"), TIMES("MultiplyByFour"), DIVIDE(
            "DivideByZero");
    private String operationName;

    private Test(final String operationName) {
        setOperationName(operationName);
    }

    public String getOperationName() {
        return operationName;
    }

    public void setOperationName(final String operationName) {
        this.operationName = operationName;
    }

    public static Test getOperationName(final String operationName) {

        for (Test oprname : Test.values()) {
            if (operationName.equals(oprname.toString())) {
                return oprname;
            }
        }
        return null;
    }

    @Override
    public String toString() {
        return operationName;
    }
}

public class Main {
    public static void main(String[] args) {

        Test test = Test.getOperationName("Plus One");
        switch (test) {
        case PLUS:
            System.out.println("Plus.....");
            break;
        case MINUS:
            System.out.println("Minus.....");
            break;

        default:
            System.out.println("Nothing..");
            break;
        }
    }
}

How do I recursively delete a directory and its entire contents (files + sub dirs) in PHP?

function deltree_cat($folder)
{
    if (is_dir($folder))
    {
             $handle = opendir($folder);
             while ($subfile = readdir($handle))
             {
                     if ($subfile == '.' or $subfile == '..') continue;
                     if (is_file($subfile)) unlink("{$folder}/{$subfile}");
                     else deltree_cat("{$folder}/{$subfile}");
             }
             closedir($handle);
             rmdir ($folder);
     }
     else
     {
        unlink($folder);
     }
}

How does one extract each folder name from a path?

public static IEnumerable<string> Split(this DirectoryInfo path)
{
    if (path == null) 
        throw new ArgumentNullException("path");
    if (path.Parent != null)
        foreach(var d in Split(path.Parent))
            yield return d;
    yield return path.Name;
}

Oracle Not Equals Operator

They are the same (as is the third form, ^=).

Note, though, that they are still considered different from the point of view of the parser, that is a stored outline defined for a != won't match <> or ^=.

This is unlike PostgreSQL where the parser treats != and <> yet on parsing stage, so you cannot overload != and <> to be different operators.

Select a random sample of results from a query result

SELECT  *
FROM    (
        SELECT  *
        FROM    mytable
        ORDER BY
                dbms_random.value
        )
WHERE rownum <= 1000

Undefined reference to `pow' and `floor'

To find the point where to add the -lm in Eclipse-IDE is really horrible, so it took me some time.

If someone else also uses Edlipse, here's the way how to add the command:

Project -> Properties -> C/C++ Build -> Settings -> GCC C Linker -> Miscelleaneous -> Linker flags: in this field add the command -lm

Ant if else condition?

The quirky syntax using conditions on the target (described by Mads) is the only supported way to perform conditional execution in core ANT.

ANT is not a programming language and when things get complicated I choose to embed a script within my build as follows:

<target name="prepare-copy" description="copy file based on condition">
    <groovy>
        if (properties["some.condition"] == "true") {
            ant.copy(file:"${properties["some.dir"]}/true", todir:".")
        }
    </groovy>
</target>

ANT supports several languages (See script task), my preference is Groovy because of it's terse syntax and because it plays so well with the build.

Apologies, David I am not a fan of ant-contrib.

How to include JavaScript file or library in Chrome console?

If anyone, fails to load because hes script violates the script-src "Content Security Policy" or "because unsafe-eval' is not an allowed", I will advice using my pretty-small module-injector as a dev-tools snippet, then you'll be able to load like this:

_x000D_
_x000D_
imports('https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.js')_x000D_
  .then(()=>alert(`today is ${moment().format('dddd')}`));
_x000D_
<script src="https://raw.githack.com/shmuelf/PowerJS/master/src/power-moduleInjector.js"></script>
_x000D_
_x000D_
_x000D_

this solution works because:

  1. It loades the library in xhr - which allows CORS from console, and avoids the script-src policy.
  2. It uses the synchronous option of xhr which allows you to stay at the console/snippet's context, so you'll have the permission to eval the script, and not to get-treated as an unsafe-eval.

How to use order by with union all in sql?

SELECT  * 
FROM 
        (
            SELECT * FROM TABLE_A 
            UNION ALL 
            SELECT * FROM TABLE_B
        ) dum
-- ORDER BY .....

but if you want to have all records from Table_A on the top of the result list, the you can add user define value which you can use for ordering,

SELECT  * 
FROM 
        (
            SELECT *, 1 sortby FROM TABLE_A 
            UNION ALL 
            SELECT *, 2 sortby FROM TABLE_B
        ) dum
ORDER   BY sortby 

How to verify static void method has been called with power mockito

If you are mocking the behavior (with something like doNothing()) there should really be no need to call to verify*(). That said, here's my stab at re-writing your test method:

@PrepareForTest({InternalUtils.class})
@RunWith(PowerMockRunner.class)
public class InternalServiceTest { //Note the renaming of the test class.
   public void testProcessOrder() {
        //Variables
        InternalService is = new InternalService();
        Order order = mock(Order.class);

        //Mock Behavior
        when(order.isSuccessful()).thenReturn(true);
        mockStatic(Internalutils.class);
        doNothing().when(InternalUtils.class); //This is the preferred way
                                               //to mock static void methods.
        InternalUtils.sendEmail(anyString(), anyString(), anyString(), anyString());

        //Execute
        is.processOrder(order);            

        //Verify
        verifyStatic(InternalUtils.class); //Similar to how you mock static methods
                                           //this is how you verify them.
        InternalUtils.sendEmail(anyString(), anyString(), anyString(), anyString());
   }
}

I grouped into four sections to better highlight what is going on:

1. Variables

I choose to declare any instance variables / method arguments / mock collaborators here. If it is something used in multiple tests, consider making it an instance variable of the test class.

2. Mock Behavior

This is where you define the behavior of all of your mocks. You're setting up return values and expectations here, prior to executing the code under test. Generally speaking, if you set the mock behavior here you wouldn't need to verify the behavior later.

3. Execute

Nothing fancy here; this just kicks off the code being tested. I like to give it its own section to call attention to it.

4. Verify

This is when you call any method starting with verify or assert. After the test is over, you check that the things you wanted to have happen actually did happen. That is the biggest mistake I see with your test method; you attempted to verify the method call before it was ever given a chance to run. Second to that is you never specified which static method you wanted to verify.

Additional Notes

This is mostly personal preference on my part. There is a certain order you need to do things in but within each grouping there is a little wiggle room. This helps me quickly separate out what is happening where.

I also highly recommend going through the examples at the following sites as they are very robust and can help with the majority of the cases you'll need:

How do I add a reference to the MySQL connector for .NET?

This is an older question, but I found it yesterday while struggling with getting the MySQL Connector reference working properly on examples I'd found on the web. I'm working with VS 2010 on Win7 64 bit but have to work with .NET 3.5.

As others have stated, you need to download the .Net & Mono versions (I don't know why this is true, but it's what I've found works). The link to the connectors is given above in the earlier answers.

  • Extract the connectors somewhere convenient.
  • Open the project in Visual Studio, then on the menu bar navigate to Solution Explorer (View > Solution Explorer), and choose Properties (first box on the far left of the toolbar. The Solution Explorer shows up in the top right pane for me, but YMMV).
  • In Properties, select References & locate the instance for mysql.data. It's likely to have a yellow bang on it (Yellow triangle with exclamation point in it). Remove it.
  • Then on the menu bar, navigate to Project > Add Reference... > Browse > point to where you downloaded the connectors. I have only been able to get the V2 version to work, but that may be a factor of my platform, not sure.
  • Clean & build your application. You should now be able to use the MySQL connectors to talk to your database.
  • You can also now downgrade your .NET instance if you need to (we're constrained to .NET 3.5, but mysql.data.dll wants 4.0 at the time of my writing this). On the menu bar, navigate to the properties of your project (Project > Properties). Choose the Application tab > Target framework > Choose which .NET framework you want to use. You have to build the application at least once before you can change the .NET framework. Once you built once the connector will no longer complain about the lower version of .NET.

Can not deserialize instance of java.lang.String out of START_OBJECT token

Resolved the problem using Jackson library. Prints are called out of Main class and all POJO classes are created. Here is the code snippets.

MainClass.java

public class MainClass {
  public static void main(String[] args) throws JsonParseException, 
       JsonMappingException, IOException {

String jsonStr = "{\r\n" + "    \"id\": 2,\r\n" + " \"socket\": \"0c317829-69bf- 
             43d6-b598-7c0c550635bb\",\r\n"
            + " \"type\": \"getDashboard\",\r\n" + "    \"data\": {\r\n"
            + "     \"workstationUuid\": \"ddec1caa-a97f-4922-833f- 
            632da07ffc11\"\r\n" + " },\r\n"
            + " \"reply\": true\r\n" + "}";

    ObjectMapper mapper = new ObjectMapper();

    MyPojo details = mapper.readValue(jsonStr, MyPojo.class);

    System.out.println("Value for getFirstName is: " + details.getId());
    System.out.println("Value for getLastName  is: " + details.getSocket());
    System.out.println("Value for getChildren is: " + 
      details.getData().getWorkstationUuid());
    System.out.println("Value for getChildren is: " + details.getReply());

}

MyPojo.java

public class MyPojo {
    private String id;

    private Data data;

    private String reply;

    private String socket;

    private String type;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public Data getData() {
        return data;
    }

    public void setData(Data data) {
        this.data = data;
    }

    public String getReply() {
        return reply;
    }

    public void setReply(String reply) {
        this.reply = reply;
    }

    public String getSocket() {
        return socket;
    }

    public void setSocket(String socket) {
        this.socket = socket;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    } 
}

Data.java

public class Data {
    private String workstationUuid;

    public String getWorkstationUuid() {
        return workstationUuid;
    }

    public void setWorkstationUuid(String workstationUuid) {
        this.workstationUuid = workstationUuid;
    }   
}

RESULTS:

Value for getFirstName is: 2
Value for getLastName  is: 0c317829-69bf-43d6-b598-7c0c550635bb
Value for getChildren is: ddec1caa-a97f-4922-833f-632da07ffc11
Value for getChildren is: true

Android: combining text & image on a Button or ImageButton

You can use this:

  <Button
                    android:id="@+id/reset_all"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginRight="5dp"
                    android:layout_weight="1"
                    android:background="@drawable/btn_med"
                    android:text="Reset all"
                    android:textColor="#ffffff" />

                <Button
                    android:id="@+id/undo"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="5dp"
                    android:layout_weight="1"
                    android:background="@drawable/btn_med"
                    android:text="Undo"
                    android:textColor="#ffffff" />

in that i have put an image as background and also added text..!

How to define servlet filter order of execution using annotations in WAR

  1. Make the servlet filter implement the spring Ordered interface.
  2. Declare the servlet filter bean manually in configuration class.
    import org.springframework.core.Ordered;
    
    public class MyFilter implements Filter, Ordered {

        @Override
        public void init(FilterConfig filterConfig) {
            // do something
        }

        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            // do something
        }

        @Override
        public void destroy() {
            // do something
        }

        @Override
        public int getOrder() {
            return -100;
        }
    }


    import org.springframework.context.annotation.ComponentScan;
    import org.springframework.context.annotation.Configuration;

    @Configuration
    @ComponentScan
    public class MyAutoConfiguration {

        @Bean
        public MyFilter myFilter() {
            return new MyFilter();
        }
    }

Converting a Pandas GroupBy output from Series to DataFrame

g1 here is a DataFrame. It has a hierarchical index, though:

In [19]: type(g1)
Out[19]: pandas.core.frame.DataFrame

In [20]: g1.index
Out[20]: 
MultiIndex([('Alice', 'Seattle'), ('Bob', 'Seattle'), ('Mallory', 'Portland'),
       ('Mallory', 'Seattle')], dtype=object)

Perhaps you want something like this?

In [21]: g1.add_suffix('_Count').reset_index()
Out[21]: 
      Name      City  City_Count  Name_Count
0    Alice   Seattle           1           1
1      Bob   Seattle           2           2
2  Mallory  Portland           2           2
3  Mallory   Seattle           1           1

Or something like:

In [36]: DataFrame({'count' : df1.groupby( [ "Name", "City"] ).size()}).reset_index()
Out[36]: 
      Name      City  count
0    Alice   Seattle      1
1      Bob   Seattle      2
2  Mallory  Portland      2
3  Mallory   Seattle      1

Is there a way to 'pretty' print MongoDB shell output to a file?

I managed to save result with writeFile() function.

> writeFile("/home/pahan/output.txt", tojson(db.myCollection.find().toArray()))

Mongo shell version was 4.0.9

Could not find or load main class with a Jar File

I was getting this error because my main class is in test package, and I am creating artifact using IntelliJ. After I checked the box Include Tests when creating artifact, it got resolved.

Screenshot from IntelliJ showing Include Tests checkbox

How to Auto-start an Android Application?

I always get in here, for this topic. I'll put my code in here so i (or other) can use it next time. (Phew hate to search into my repository code).

Add the permission:

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

Add receiver and service:

<receiver android:enabled="true" android:name=".BootUpReceiver"
    android:permission="android.permission.RECEIVE_BOOT_COMPLETED">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</receiver>
<service android:name="Launcher" />

Create class Launcher:

public class Launcher extends Service {
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        new AsyncTask<Service, Void, Service>() {

            @Override
            protected Service doInBackground(Service... params) {
                Service service = params[0];
                PackageManager pm = service.getPackageManager();
                try {
                    Intent target = pm.getLaunchIntentForPackage("your.package.id");
                    if (target != null) {
                        service.startActivity(target);
                        synchronized (this) {
                            wait(3000);
                        }
                    } else {
                        throw new ActivityNotFoundException();
                    }
                } catch (ActivityNotFoundException | InterruptedException ignored) {
                }
                return service;
            }

            @Override
            protected void onPostExecute(Service service) {
                service.stopSelf();
            }

        }.execute(this);

        return START_STICKY;
    }
}

Create class BootUpReceiver to do action after android reboot.

For example launch MainActivity:

public class BootUpReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {
        Intent target = new Intent(context, MainActivity.class);  
        target.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(target);  
    }
}

Simple int to char[] conversion

If you want to convert an int which is in the range 0-9 to a char, you may usually write something like this:

int x;
char c = '0' + x;

Now, if you want a character string, just add a terminating '\0' char:

char s[] = {'0' + x, '\0'};

Note that:

  1. You must be sure that the int is in the 0-9 range, otherwise it will fail,
  2. It works only if character codes for digits are consecutive. This is true in the vast majority of systems, that are ASCII-based, but this is not guaranteed to be true in all cases.

How to detect responsive breakpoints of Twitter Bootstrap 3 using JavaScript?

For anyone interested in this, i wrote a breakpoint detection based on CSS breakpoints using TypeScript and Observables. it is not very hard to make ES6 out of it, if you remove the types. In my example i use Sass, but it is also easy to remove this.

Here is my JSFiddle: https://jsfiddle.net/StefanJelner/dorj184g/

HTML:

<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/5.5.7/Rx.min.js"></script>
<div id="result"></div>

SCSS:

body::before {
  content: 'xs';
  display: none;

  @media screen and (min-width: 480px) {
    content: 's';
  }

  @media screen and (min-width: 768px) {
    content: 'm';
  }

  @media screen and (min-width: 1024px) {
    content: 'l';
  }

  @media screen and (min-width: 1280px) {
    content: 'xl';
  }
}

TypeScript:

import { BehaviorSubject } from 'rxjs/BehaviorSubject';
import { Observable } from 'rxjs/Observable';

class BreakpointChangeService {
    private breakpointChange$: BehaviorSubject<string>;

    constructor(): BehaviorSubject<string> {
        // initialize BehaviorSubject with the current content of the ::before pseudo element
        this.breakpointChange$ = new Rx.BehaviorSubject(this.getBreakpoint());

        // observe the window resize event, throttle it and combine it with the BehaviorSubject
        Rx.Observable
            .fromEvent(window, 'resize')
            .throttleTime(0, Rx.Scheduler.animationFrame)
            .withLatestFrom(this.breakpointChange$)
            .subscribe(this.update.bind(this))
        ;

        return this.breakpointChange$;
    }

    // method to get the content of the ::before pseudo element
    private getBreakpoint(): string {
        // see https://www.lullabot.com/articles/importing-css-breakpoints-into-javascript
        return window.getComputedStyle(document.body, ':before').getPropertyValue('content').replace(/[\"\']/g, '');
    }

    private update(_, recent): void {
        var current = this.getBreakpoint();
        if(recent !== current) { this.breakpointChange$.next(current); }
    }
}

// if the breakpoint changes, react on it
var $result = document.getElementById('result');
new BreakpointChangeService().subscribe(breakpoint => {
    $result.innerHTML = Date.now()+': '+breakpoint;
});

I hope this helps somebody.

Read file As String

You can use org.apache.commons.io.IOUtils.toString(InputStream is, Charset chs) to do that.

e.g.

IOUtils.toString(context.getResources().openRawResource(<your_resource_id>), StandardCharsets.UTF_8)

For adding the correct library:

Add the following to your app/build.gradle file:

dependencies {
    compile 'org.apache.directory.studio:org.apache.commons.io:2.4'
}

or for the Maven repo see -> this link

For direct jar download see-> https://commons.apache.org/proper/commons-io/download_io.cgi

jQuery '.each' and attaching '.click' event

One solution you could use is to assign a more generalized class to any div you want the click event handler bound to.

For example:

HTML:

<body>
<div id="dog" class="selected" data-selected="false">dog</div>
<div id="cat" class="selected" data-selected="true">cat</div>
<div id="mouse" class="selected" data-selected="false">mouse</div>

<div class="dog"><img/></div>
<div class="cat"><img/></div>
<div class="mouse"><img/></div>
</body>

JS:

$( ".selected" ).each(function(index) {
    $(this).on("click", function(){
        // For the boolean value
        var boolKey = $(this).data('selected');
        // For the mammal value
        var mammalKey = $(this).attr('id'); 
    });
});

How can I convert a string to upper- or lower-case with XSLT?

In XSLT 1.0 the upper-case() and lower-case() functions are not available. If you're using a 1.0 stylesheet the common method of case conversion is translate():

<xsl:variable name="lowercase" select="'abcdefghijklmnopqrstuvwxyz'" />
<xsl:variable name="uppercase" select="'ABCDEFGHIJKLMNOPQRSTUVWXYZ'" />


<xsl:template match="/">
  <xsl:value-of select="translate(doc, $lowercase, $uppercase)" />
</xsl:template>

What are some ways of accessing Microsoft SQL Server from Linux?

sql-cli is a nodejs based cross platform command line interface for sql server. You can install it via npm https://www.npmjs.org/package/sql-cli

It can connect to both on-premise and sql azure instance.

Woocommerce get products

<?php
$args     = array( 'post_type' => 'product', 'category' => 34, 'posts_per_page' => -1 );
$products = get_posts( $args ); 
?>

This should grab all the products you want, I may have the post type wrong though I can't quite remember what woo-commerce uses for the post type. It will return an array of products

Inheriting from a template class in c++

For understanding templates, it's of huge advantage to get the terminology straight because the way you speak about them determines the way to think about them.

Specifically, Area is not a template class, but a class template. That is, it is a template from which classes can be generated. Area<int> is such a class (it's not an object, but of course you can create an object from that class in the same ways you can create objects from any other class). Another such class would be Area<char>. Note that those are completely different classes, which have nothing in common except for the fact that they were generated from the same class template.

Since Area is not a class, you cannot derive the class Rectangle from it. You only can derive a class from another class (or several of them). Since Area<int> is a class, you could, for example, derive Rectangle from it:

class Rectangle:
  public Area<int>
{
  // ...
};

Since Area<int> and Area<char> are different classes, you can even derive from both at the same time (however when accessing members of them, you'll have to deal with ambiguities):

class Rectangle:
  public Area<int>,
  public Area<char>
{
  // ...
};

However you have to specify which classed to derive from when you define Rectangle. This is true no matter whether those classes are generated from a template or not. Two objects of the same class simply cannot have different inheritance hierarchies.

What you can do is to make Rectangle a template as well. If you write

template<typename T> class Rectangle:
  public Area<T>
{
  // ...
};

You have a template Rectangle from which you can get a class Rectangle<int> which derives from Area<int>, and a different class Rectangle<char> which derives from Area<char>.

It may be that you want to have a single type Rectangle so that you can pass all sorts of Rectangle to the same function (which itself doesn't need to know the Area type). Since the Rectangle<T> classes generated by instantiating the template Rectangle are formally independent of each other, it doesn't work that way. However you can make use of multiple inheritance here:

class Rectangle // not inheriting from any Area type
{
  // Area independent interface
};

template<typename T> class SpecificRectangle:
  public Rectangle,
  public Area<T>
{
  // Area dependent stuff
};

void foo(Rectangle&); // A function which works with generic rectangles

int main()
{
  SpecificRectangle<int> intrect;
  foo(intrect);

  SpecificRectangle<char> charrect;
  foo(charrect);
}

If it is important that your generic Rectangle is derived from a generic Area you can do the same trick with Area too:

class Area
{
  // generic Area interface
};

class Rectangle:
  public virtual Area // virtual because of "diamond inheritance"
{
  // generic rectangle interface
};

template<typename T> class SpecificArea:
  public virtual Area
{
  // specific implementation of Area for type T
};

template<typename T> class SpecificRectangle:
  public Rectangle, // maybe this should be virtual as well, in case the hierarchy is extended later
  public SpecificArea<T> // no virtual inheritance needed here
{
  // specific implementation of Rectangle for type T
};

Fastest way to download a GitHub project

Another faster way of downloading a GitHub project would be to use the clone functionality with the --depth argument as:

git clone --depth=1 [email protected]:organization/your-repo.git

to perform a shallow clone.

Is it more efficient to copy a vector by reserving and copying, or by creating and swapping?

you should not use swap to copy vectors, it would change the "original" vector.

pass the original as a parameter to the new instead.

Links not going back a directory?

You need to give a relative file path of <a href="../index.html">Home</a>

Alternately you can specify a link from the root of your site with <a href="/pages/en/index.html">Home</a>

.. and . have special meanings in file paths, .. means up one directory and . means current directory.

so <a href="index.html">Home</a> is the same as <a href="./index.html">Home</a>

How to pick an image from gallery (SD Card) for my app?

#initialize in main activity 
    path = Environment.getExternalStorageDirectory()
            + "/images/make_machine_example.jpg"; #
     ImageView image=(ImageView)findViewById(R.id.image);
 //--------------------------------------------------||

 public void FromCamera(View) {

    Log.i("camera", "startCameraActivity()");
    File file = new File(path);
    Uri outputFileUri = Uri.fromFile(file);
    Intent intent = new Intent(
            android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
    startActivityForResult(intent, 1);

}

public void FromCard() {
    Intent i = new Intent(Intent.ACTION_PICK,
            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    startActivityForResult(i, 2);
}

 protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == 2 && resultCode == RESULT_OK
            && null != data) {

        Uri selectedImage = data.getData();
        String[] filePathColumn = { MediaStore.Images.Media.DATA };

        Cursor cursor = getContentResolver().query(selectedImage,
                filePathColumn, null, null, null);
        cursor.moveToFirst();

        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String picturePath = cursor.getString(columnIndex);
        cursor.close();

        bitmap = BitmapFactory.decodeFile(picturePath);
        image.setImageBitmap(bitmap);

        if (bitmap != null) {
            ImageView rotate = (ImageView) findViewById(R.id.rotate);

        }

    } else {

        Log.i("SonaSys", "resultCode: " + resultCode);
        switch (resultCode) {
        case 0:
            Log.i("SonaSys", "User cancelled");
            break;
        case -1:
            onPhotoTaken();
            break;

        }

    }

}

protected void onPhotoTaken() {
    // Log message
    Log.i("SonaSys", "onPhotoTaken");
    taken = true;
    imgCapFlag = true;
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inSampleSize = 4;
    bitmap = BitmapFactory.decodeFile(path, options);
    image.setImageBitmap(bitmap);


}

How do I get DOUBLE_MAX?

Using double to store large integers is dubious; the largest integer that can be stored reliably in double is much smaller than DBL_MAX. You should use long long, and if that's not enough, you need your own arbitrary-precision code or an existing library.

Select last row in MySQL

You can use an OFFSET in a LIMIT command:

SELECT * FROM aTable LIMIT 1 OFFSET 99

in case your table has 100 rows this return the last row without relying on a primary_key

What's the net::ERR_HTTP2_PROTOCOL_ERROR about?

I got the same issue (asp, c# - HttpPostedFileBase) when posting a file that was larger than 1MB (even though application doesn't have any limitation for file size), for me the simplification of model class helped. If you got this issue, try to remove some parts of the model, and see if it will help in any way. Sounds strange, but worked for me.

Differences between ConstraintLayout and RelativeLayout

The Conclusion I can make is

1) We can do UI design without touching the xml part of code, to be honest I feel google has copied how UI is designed in iOS apps, it will make sense if you are familiar with UI development in iOS, but in relative layout its hard to set the constraints without touching the xml design.

2) Secondly it has flat view hierarchy unlike other layouts, so does better performance than relative layout which you might have seen from other answers

3) It also have extra things apart from what relative layout has, such as circular relative positioning where we can position another view relative to this one at certain radius with certain angle which cant do in relative layout

I am saying it again, designing UI using constraint layout is same as designing UI in iOS, so in future if you work on iOS you will find it easier if you have used constraint layout

Display animated GIF in iOS

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

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

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

How Should I Set Default Python Version In Windows?

The Python installer installs Python Launcher for Windows. This program (py.exe) is associated with the Python file extensions and looks for a "shebang" comment to specify the python version to run. This allows many versions of Python to co-exist and allows Python scripts to explicitly specify which version to use, if desired. If it is not specified, the default is to use the latest Python version for the current architecture (x86 or x64). This default can be customized through a py.ini file or PY_PYTHON environment variable. See the docs for more details.

Newer versions of Python update the launcher. The latest version has a py -0 option to list the installed Pythons and indicate the current default.

Here's how to check if the launcher is registered correctly from the console:

C:\>assoc .py
.py=Python.File

C:\>ftype Python.File
Python.File="C:\Windows\py.exe" "%1" %*

Above, .py files are associated with the Python.File type. The command line for Python.File is the Python Launcher, which is installed in the Windows directory since it is always in the PATH.

For the association to work, run scripts from the command line with script.py, not "python script.py", otherwise python will be run instead of py. If fact it's best to remove Python directories from the PATH, so "python" won't run anything and enforce using py.

py.exe can also be run with switches to force a Python version:

py -3 script.py       # select latest Python 3.X version to be used.
py -3.6 script.py     # select version 3.6 specifically.
py -3.9-32 script.py  # select version 3.9 32-bit specifically.
py -0                 # list installed Python versions (latest PyLauncher).

Additionally, add .py;.pyw;.pyc;.pyo to the PATHEXT environment variable and then the command line can just be script with no extension.

How to convert integers to characters in C?

void main ()
 {
    int temp,integer,count=0,i,cnd=0;
    char ascii[10]={0};
    printf("enter a number");
    scanf("%d",&integer);
     if(integer>>31)
     {
     /*CONVERTING 2's complement value to normal value*/    
     integer=~integer+1;    
     for(temp=integer;temp!=0;temp/=10,count++);    
     ascii[0]=0x2D;
     count++;
     cnd=1;
     }
     else
     for(temp=integer;temp!=0;temp/=10,count++);    
     for(i=count-1,temp=integer;i>=cnd;i--)
     {

        ascii[i]=(temp%10)+0x30;
        temp/=10;
     }
    printf("\n count =%d ascii=%s ",count,ascii);

 }

Difference between /res and /assets directories

With resources, there's built-in support for providing alternatives for different languages, OS versions, screen orientations, etc., as described here. None of that is available with assets. Also, many parts of the API support the use of resource identifiers. Finally, the names of the resources are turned into constant field names that are checked at compile time, so there's less of an opportunity for mismatches between the code and the resources themselves. None of that applies to assets.

So why have an assets folder at all? If you want to compute the asset you want to use at run time, it's pretty easy. With resources, you would have to declare a list of all the resource IDs that might be used and compute an index into the the list. (This is kind of awkward and introduces opportunities for error if the set of resources changes in the development cycle.) (EDIT: you can retrieve a resource ID by name using getIdentifier, but this loses the benefits of compile-time checking.) Assets can also be organized into a folder hierarchy, which is not supported by resources. It's a different way of managing data. Although resources cover most of the cases, assets have their occasional use.

One other difference: resources defined in a library project are automatically imported to application projects that depend on the library. For assets, that doesn't happen; asset files must be present in the assets directory of the application project(s). [EDIT: With Android's new Gradle-based build system (used with Android Studio), this is no longer true. Asset directories for library projects are packaged into the .aar files, so assets defined in library projects are merged into application projects (so they do not have to be present in the application's /assets directory if they are in a referenced library).]

EDIT: Yet another difference arises if you want to package a custom font with your app. There are API calls to create a Typeface from a font file stored in the file system or in your app's assets/ directory. But there is no API to create a Typeface from a font file stored in the res/ directory (or from an InputStream, which would allow use of the res/ directory). [NOTE: With Android O (now available in alpha preview) you will be able to include custom fonts as resources. See the description here of this long-overdue feature. However, as long as your minimum API level is 25 or less, you'll have to stick with packaging custom fonts as assets rather than as resources.]

SQL "between" not inclusive

It is inclusive. You are comparing datetimes to dates. The second date is interpreted as midnight when the day starts.

One way to fix this is:

SELECT *
FROM Cases
WHERE cast(created_at as date) BETWEEN '2013-05-01' AND '2013-05-01'

Another way to fix it is with explicit binary comparisons

SELECT *
FROM Cases
WHERE created_at >= '2013-05-01' AND created_at < '2013-05-02'

Aaron Bertrand has a long blog entry on dates (here), where he discusses this and other date issues.

Why is IoC / DI not common in Python?

I think due to the dynamic nature of python people don't often see the need for another dynamic framework. When a class inherits from the new-style 'object' you can create a new variable dynamically (https://wiki.python.org/moin/NewClassVsClassicClass).

i.e. In plain python:

#application.py
class Application(object):
    def __init__(self):
        pass

#main.py
Application.postgres_connection = PostgresConnection()

#other.py
postgres_connection = Application.postgres_connection
db_data = postgres_connection.fetchone()

However have a look at https://github.com/noodleflake/pyioc this might be what you are looking for.

i.e. In pyioc

from libs.service_locator import ServiceLocator

#main.py
ServiceLocator.register(PostgresConnection)

#other.py
postgres_connection = ServiceLocator.resolve(PostgresConnection)
db_data = postgres_connection.fetchone()

What are the options for storing hierarchical data in a relational database?

I am using PostgreSQL with closure tables for my hierarchies. I have one universal stored procedure for the whole database:

CREATE FUNCTION nomen_tree() RETURNS trigger
    LANGUAGE plpgsql
    AS $_$
DECLARE
  old_parent INTEGER;
  new_parent INTEGER;
  id_nom INTEGER;
  txt_name TEXT;
BEGIN
-- TG_ARGV[0] = name of table with entities with PARENT-CHILD relationships (TBL_ORIG)
-- TG_ARGV[1] = name of helper table with ANCESTOR, CHILD, DEPTH information (TBL_TREE)
-- TG_ARGV[2] = name of the field in TBL_ORIG which is used for the PARENT-CHILD relationship (FLD_PARENT)
    IF TG_OP = 'INSERT' THEN
    EXECUTE 'INSERT INTO ' || TG_ARGV[1] || ' (child_id,ancestor_id,depth) 
        SELECT $1.id,$1.id,0 UNION ALL
      SELECT $1.id,ancestor_id,depth+1 FROM ' || TG_ARGV[1] || ' WHERE child_id=$1.' || TG_ARGV[2] USING NEW;
    ELSE                                                           
    -- EXECUTE does not support conditional statements inside
    EXECUTE 'SELECT $1.' || TG_ARGV[2] || ',$2.' || TG_ARGV[2] INTO old_parent,new_parent USING OLD,NEW;
    IF COALESCE(old_parent,0) <> COALESCE(new_parent,0) THEN
      EXECUTE '
      -- prevent cycles in the tree
      UPDATE ' || TG_ARGV[0] || ' SET ' || TG_ARGV[2] || ' = $1.' || TG_ARGV[2]
        || ' WHERE id=$2.' || TG_ARGV[2] || ' AND EXISTS(SELECT 1 FROM '
        || TG_ARGV[1] || ' WHERE child_id=$2.' || TG_ARGV[2] || ' AND ancestor_id=$2.id);
      -- first remove edges between all old parents of node and its descendants
      DELETE FROM ' || TG_ARGV[1] || ' WHERE child_id IN
        (SELECT child_id FROM ' || TG_ARGV[1] || ' WHERE ancestor_id = $1.id)
        AND ancestor_id IN
        (SELECT ancestor_id FROM ' || TG_ARGV[1] || ' WHERE child_id = $1.id AND ancestor_id <> $1.id);
      -- then add edges for all new parents ...
      INSERT INTO ' || TG_ARGV[1] || ' (child_id,ancestor_id,depth) 
        SELECT child_id,ancestor_id,d_c+d_a FROM
        (SELECT child_id,depth AS d_c FROM ' || TG_ARGV[1] || ' WHERE ancestor_id=$2.id) AS child
        CROSS JOIN
        (SELECT ancestor_id,depth+1 AS d_a FROM ' || TG_ARGV[1] || ' WHERE child_id=$2.' 
        || TG_ARGV[2] || ') AS parent;' USING OLD, NEW;
    END IF;
  END IF;
  RETURN NULL;
END;
$_$;

Then for each table where I have a hierarchy, I create a trigger

CREATE TRIGGER nomenclature_tree_tr AFTER INSERT OR UPDATE ON nomenclature FOR EACH ROW EXECUTE PROCEDURE nomen_tree('my_db.nomenclature', 'my_db.nom_helper', 'parent_id');

For populating a closure table from existing hierarchy I use this stored procedure:

CREATE FUNCTION rebuild_tree(tbl_base text, tbl_closure text, fld_parent text) RETURNS void
    LANGUAGE plpgsql
    AS $$
BEGIN
    EXECUTE 'TRUNCATE ' || tbl_closure || ';
    INSERT INTO ' || tbl_closure || ' (child_id,ancestor_id,depth) 
        WITH RECURSIVE tree AS
      (
        SELECT id AS child_id,id AS ancestor_id,0 AS depth FROM ' || tbl_base || '
        UNION ALL 
        SELECT t.id,ancestor_id,depth+1 FROM ' || tbl_base || ' AS t
        JOIN tree ON child_id = ' || fld_parent || '
      )
      SELECT * FROM tree;';
END;
$$;

Closure tables are defined with 3 columns - ANCESTOR_ID, DESCENDANT_ID, DEPTH. It is possible (and I even advice) to store records with same value for ANCESTOR and DESCENDANT, and a value of zero for DEPTH. This will simplify the queries for retrieval of the hierarchy. And they are very simple indeed:

-- get all descendants
SELECT tbl_orig.*,depth FROM tbl_closure LEFT JOIN tbl_orig ON descendant_id = tbl_orig.id WHERE ancestor_id = XXX AND depth <> 0;
-- get only direct descendants
SELECT tbl_orig.* FROM tbl_closure LEFT JOIN tbl_orig ON descendant_id = tbl_orig.id WHERE ancestor_id = XXX AND depth = 1;
-- get all ancestors
SELECT tbl_orig.* FROM tbl_closure LEFT JOIN tbl_orig ON ancestor_id = tbl_orig.id WHERE descendant_id = XXX AND depth <> 0;
-- find the deepest level of children
SELECT MAX(depth) FROM tbl_closure WHERE ancestor_id = XXX;

Cause of No suitable driver found for

"no suitable driver" usually means that the syntax for the connection URL is incorrect.

How to rollback everything to previous commit

I searched for multiple options to get my git reset to specific commit, but most of them aren't so satisfactory.

I generally use this to reset the git to the specific commit in source tree.

  1. select commit to reset on sourcetree.

  2. In dropdowns select the active branch , first Parent Only

  3. And right click on "Reset branch to this commit" and select hard reset option (soft, mixed and hard)

  4. and then go to terminal git push -f

You should be all set!

How to add footnotes to GitHub-flavoured Markdown?

GitHub Flavored Markdown doesn't support footnotes, but you can manually fake it¹ with Unicode characters or superscript tags, e.g. <sup>1</sup>.

¹Of course this isn't ideal, as you are now responsible for maintaining the numbering of your footnotes. It works reasonably well if you only have one or two, though.

saving a file (from stream) to disk using c#

For the filestream:

//Check if the directory exists
if (!System.IO.Directory.Exists(@"C:\yourDirectory"))
{
    System.IO.Directory.CreateDirectory(@"C:\yourDirectory");
}

//Write the file
using (System.IO.StreamWriter outfile = new System.IO.StreamWriter(@"C:\yourDirectory\yourFile.txt"))
{
    outfile.Write(yourFileAsString);
}

MVC ajax post to controller action method

Your Action is expecting string parameters, but you're sending a composite object.

You need to create an object that matches what you're sending.

public class Data
{
    public string username { get;set; }
    public string password { get;set; }
}

public JsonResult Login(Data data)
{
}

EDIT

In addition, toStringify() is probably not what you want here. Just send the object itself.

data: data,

Problems using Maven and SSL behind proxy

You can import the SSL cert manually and just add it to the keystore.

For linux users,

Syntax:

keytool -trustcacerts -keystore /jre/lib/security/cacerts -storepass changeit -importcert -alias nexus -file

Example :

keytool -trustcacerts -keystore /Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home/jre/lib/security/cacerts -storepass changeit -importcert -alias nexus -file ~/Downloads/abc.com-ssl.crt

EXCEL Multiple Ranges - need different answers for each range

use

=VLOOKUP(D4,F4:G9,2)

with the range F4:G9:

0   0.1
1   0.15
5   0.2
15  0.3
30  1
100 1.3

and D4 being the value in question, e.g. 18.75 -> result: 0.3

fastest way to export blobs from table into individual files

I tried using a CLR function and it was more than twice as fast as BCP. Here's my code.

Original Method:

SET @bcpCommand = 'bcp "SELECT blobcolumn FROM blobtable WHERE ID = ' + CAST(@FileID AS VARCHAR(20)) + '" queryout "' + @FileName + '" -T -c'
EXEC master..xp_cmdshell @bcpCommand

CLR Method:

declare @file varbinary(max) = (select blobcolumn from blobtable WHERE ID = @fileid)
declare @filepath nvarchar(4000) = N'c:\temp\' + @FileName
SELECT Master.dbo.WriteToFile(@file, @filepath, 0)

C# Code for the CLR function

using System;
using System.Data;
using System.Data.SqlTypes;
using System.IO;
using Microsoft.SqlServer.Server;

namespace BlobExport
{
    public class Functions
    {
      [SqlFunction]
      public static SqlString WriteToFile(SqlBytes binary, SqlString path, SqlBoolean append)
      {        
        try
        {
          if (!binary.IsNull && !path.IsNull && !append.IsNull)
          {         
            var dir = Path.GetDirectoryName(path.Value);           
            if (!Directory.Exists(dir))              
              Directory.CreateDirectory(dir);            
              using (var fs = new FileStream(path.Value, append ? FileMode.Append : FileMode.OpenOrCreate))
            {
                byte[] byteArr = binary.Value;
                for (int i = 0; i < byteArr.Length; i++)
                {
                    fs.WriteByte(byteArr[i]);
                };
            }
            return "SUCCESS";
          }
          else
             "NULL INPUT";
        }
        catch (Exception ex)
        {          
          return ex.Message;
        }
      }
    }
}

How do you convert a DataTable into a generic list?

Output

public class ModelUser
{
    #region Model

    private string _username;
    private string _userpassword;
    private string _useremail;
    private int _userid;

    /// <summary>
    /// 
    /// </summary>
    public int userid
    {
        set { _userid = value; }
        get { return _userid; }
    }


    /// <summary>
    /// 
    /// </summary>

    public string username
    {
        set { _username = value; }
        get { return _username; }
    }

    /// <summary>
    /// 
    /// </summary>
    public string useremail
    {
        set { _useremail = value; }
        get { return _useremail; }
    }

    /// <summary>
    /// 
    /// </summary>
    public string userpassword
    {
        set { _userpassword = value; }
        get { return _userpassword; }
    }
    #endregion Model
}

public List<ModelUser> DataTableToList(DataTable dt)
{
    List<ModelUser> modelList = new List<ModelUser>();
    int rowsCount = dt.Rows.Count;
    if (rowsCount > 0)
    {
        ModelUser model;
        for (int n = 0; n < rowsCount; n++)
        {
            model = new ModelUser();

            model.userid = (int)dt.Rows[n]["userid"];
            model.username = dt.Rows[n]["username"].ToString();
            model.useremail = dt.Rows[n]["useremail"].ToString();
            model.userpassword = dt.Rows[n]["userpassword"].ToString();

            modelList.Add(model);
        }
    }
    return modelList;
}

static DataTable GetTable()
{
    // Here we create a DataTable with four columns.
    DataTable table = new DataTable();
    table.Columns.Add("userid", typeof(int));
    table.Columns.Add("username", typeof(string));
    table.Columns.Add("useremail", typeof(string));
    table.Columns.Add("userpassword", typeof(string));

    // Here we add five DataRows.
    table.Rows.Add(25, "Jame", "[email protected]", DateTime.Now.ToString());
    table.Rows.Add(50, "luci", "[email protected]", DateTime.Now.ToString());
    table.Rows.Add(10, "Andrey", "[email protected]", DateTime.Now.ToString());
    table.Rows.Add(21, "Michael", "[email protected]", DateTime.Now.ToString());
    table.Rows.Add(100, "Steven", "[email protected]", DateTime.Now.ToString());
    return table;
}

protected void Page_Load(object sender, EventArgs e)
{
    List<ModelUser> userList = new List<ModelUser>();

    DataTable dt = GetTable();

    userList = DataTableToList(dt);

    gv.DataSource = userList;
    gv.DataBind();
}[enter image description here][1]

</asp:GridView>
</div>

In c# what does 'where T : class' mean?

It's a type constraint on T, specifying that it must be a class.

The where clause can be used to specify other type constraints, e.g.:

where T : struct // T must be a struct
where T : new()  // T must have a default parameterless constructor
where T : IComparable // T must implement the IComparable interface

For more information, check out MSDN's page on the where clause, or generic parameter constraints.

IntelliJ how to zoom in / out

I assume that you have a similar view regarding the zoom functionality as I have in this picture:

enter image description here

Now if you mark one of the Zoom In/Zoom Out lines and choose Add Keyboard Shortcut:

enter image description here

You will find that this particular shortcut Numpad + is already occupied so there is a conflict:

enter image description here

So you'll just have assign this Zoom In/Zoom Out to some other keyboard shortcut:

enter image description here

Maven does not find JUnit tests to run

If you have a shared Java / Groovy application and all you have are Groovy unit tests, then Maven won't find any tests. This can be fixed by adding one unit test under src/test/java.

Just disable scroll not hide it?

I have made this one function, that solves this problem with JS. This principle can be easily extended and customized that is a big pro for me.

Using this js DOM API function:

const handleWheelScroll = (element) => (event) => {
  if (!element) {
    throw Error("Element for scroll was not found");
  }
  const { deltaY } = event;
  const { clientHeight, scrollTop, scrollHeight } = element;
  if (deltaY < 0) {
    if (-deltaY > scrollTop) {
      element.scrollBy({
        top: -scrollTop,
        behavior: "smooth",
      });
      event.stopPropagation();
      event.preventDefault();
    }
    return;
  }

  if (deltaY > scrollHeight - clientHeight - scrollTop) {
    element.scrollBy({
      top: scrollHeight - clientHeight - scrollTop,
      behavior: "smooth",
    });
    event.stopPropagation();
    event.preventDefault();
    return;
  }
};

In short, this function will stop event propagation and default behavior if the scroll would scroll something else then the given element (the one you want to scroll in).

Then you can hook and unhook this up like this:

const wheelEventHandler = handleWheelScroll(elementToScrollIn);

window.addEventListener("wheel", wheelEventHandler, {
    passive: false,
});

window.removeEventListener("wheel", wheelEventHandler);

Watch out for that it is a higher order function so you have to keep a reference to the given instance.

I hook the addEventListener part in mouse enter and unhook the removeEventListener in mouse leave events in jQuery, but you can use it as you like.

How can I get the status code from an http error in Axios?

I am using this interceptors to get the error response.

const HttpClient = axios.create({
  baseURL: env.baseUrl,
});

HttpClient.interceptors.response.use((response) => {
  return response;
}, (error) => {
  return Promise.resolve({ error });
});

Print in one line dynamically

"By the way...... How to refresh it every time so it print mi in one place just change the number."

It's really tricky topic. What zack suggested ( outputting console control codes ) is one way to achieve that.

You can use (n)curses, but that works mainly on *nixes.

On Windows (and here goes interesting part) which is rarely mentioned (I can't understand why) you can use Python bindings to WinAPI (http://sourceforge.net/projects/pywin32/ also with ActivePython by default) - it's not that hard and works well. Here's a small example:

import win32console, time

output_handle = win32console.GetStdHandle(  win32console.STD_OUTPUT_HANDLE )
info = output_handle.GetConsoleScreenBufferInfo()
pos = info["CursorPosition"]

for i in "\\|/-\\|/-":
    output_handle.WriteConsoleOutputCharacter( i, pos )
    time.sleep( 1 )

Or, if you want to use print (statement or function, no difference):

import win32console, time

output_handle = win32console.GetStdHandle(  win32console.STD_OUTPUT_HANDLE )
info = output_handle.GetConsoleScreenBufferInfo()
pos = info["CursorPosition"]

for i in "\\|/-\\|/-":
    print i
    output_handle.SetConsoleCursorPosition( pos )
    time.sleep( 1 )

win32console module enables you to do many more interesting things with windows console... I'm not a big fan of WinAPI, but recently I realized that at least half of my antipathy towards it was caused by writing WinAPI code in C - pythonic bindings are much easier to use.

All other answers are great and pythonic, of course, but... What if I wanted to print on previous line? Or write multiline text, than clear it and write the same lines again? My solution makes that possible.

Apache Prefork vs Worker MPM

Take a look at this for more detail. It refers to how Apache handles multiple requests. Preforking, which is the default, starts a number of Apache processes (2 by default here, though I believe one can configure this through httpd.conf). Worker MPM will start a new thread per request, which I would guess, is more memory efficient. Historically, Apache has used prefork, so it's a better-tested model. Threading was only added in 2.0.

CASE IN statement with multiple values

If you have more numbers or if you intend to add new test numbers for CASE then you can use a more flexible approach:

DECLARE @Numbers TABLE
(
    Number VARCHAR(50) PRIMARY KEY
    ,Class TINYINT NOT NULL
);
INSERT @Numbers
VALUES ('1121231',1);
INSERT @Numbers
VALUES ('31242323',1);
INSERT @Numbers
VALUES ('234523',2);
INSERT @Numbers
VALUES ('2342423',2);

SELECT c.*, n.Class
FROM   tblClient c  
LEFT OUTER JOIN   @Numbers n ON c.Number = n.Number;

Also, instead of table variable you can use a regular table.

How to increase Java heap space for a tomcat app

Your change may well be working. Does your application need a lot of memory - the stack trace shows some Image related features.

I'm guessing that the error either happens right away, with a large file, or happens later after several requests.

If the error happens right away, then you can increase memory still further, or investigate find out why so much memory is needed for one file.

If the error happens after several requests, then you could have a memory leak - where objects are not being reclaimed by the garbage collector. Using a tool like JProfiler can help you monitor how much memory is being used by your VM and can help you see what is using that memory and why objects are not being reclaimed by the garbage collector.

How to set CATALINA_HOME variable in windows 7?

Setting the JAVA_HOME, CATALINA_HOME Environment Variable on Windows

One can do using command prompt:

  1. set JAVA_HOME=C:\ "top level directory of your java install"
  2. set CATALINA_HOME=C:\ "top level directory of your Tomcat install"
  3. set PATH=%PATH%;%JAVA_HOME%\bin;%CATALINA_HOME%\bin

OR you can do the same:

  1. Go to system properties
  2. Go to environment variables and add a new variable with the name JAVA_HOME and provide variable value as C:\ "top level directory of your java install"
  3. Go to environment variables and add a new variable with the name CATALINA_HOME and provide variable value as C:\ "top level directory of your Tomcat install"
  4. In path variable add a new variable value as ;%CATALINA_HOME%\bin;

Static Vs. Dynamic Binding in Java

In the case of the static binding type of object determined at the compile-time whereas in the dynamic binding type of the object is determined at the runtime.



class Dainamic{

    void run2(){
        System.out.println("dainamic_binding");
    }

}


public class StaticDainamicBinding extends Dainamic {

    void run(){
        System.out.println("static_binding");
    }

    @Override
    void run2() {
        super.run2();
    }

    public static void main(String[] args) {
        StaticDainamicBinding st_vs_dai = new StaticDainamicBinding();
        st_vs_dai.run();
        st_vs_dai.run2();
    }

}

Two divs side by side - Fluid display

This is easy with a flexbox:

_x000D_
_x000D_
#wrapper {_x000D_
  display: flex;_x000D_
}_x000D_
_x000D_
#left {_x000D_
  flex: 0 0 65%;_x000D_
}_x000D_
_x000D_
#right {_x000D_
  flex: 1;_x000D_
}
_x000D_
<div id="wrapper">_x000D_
  <div id="left">Left side div</div>_x000D_
  <div id="right">Right side div</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to get name of the computer in VBA?

Looks like I'm late to the game, but this is a common question...

This is probably the code you want.

Please note that this code is in the public domain, from Usenet, MSDN, and the Excellerando blog.

Public Function ComputerName() As String
'' Returns the host name

'' Uses late-binding: bad for performance and stability, useful for 
'' code portability. The correct declaration is:

'   Dim objNetwork  As IWshRuntimeLibrary.WshNetwork
'   Set objNetwork = New IWshRuntimeLibrary.WshNetwork

    Dim objNetwork As Object
    Set objNetwork = CreateObject("WScript.Network")

    ComputerName = objNetwork.ComputerName
    
    Set objNetwork = Nothing

End Function

You'll probably need this, too:

Public Function UserName(Optional WithDomain As Boolean = False) As String
'' Returns the user's network name

'' Uses late-binding: bad for performance and stability, useful for
'' code portability. The correct declaration is:

'   Dim objNetwork  As IWshRuntimeLibrary.WshNetwork
'   Set objNetwork = New IWshRuntimeLibrary.WshNetwork


    Dim objNetwork As Object
    Set objNetwork = CreateObject("WScript.Network")

    If WithDomain Then
        UserName = objNetwork.UserDomain & "\" & objNetwork.UserName
    Else
        UserName = objNetwork.UserName
    End If
    
    Set objNetwork = Nothing

End Function

What is the difference between a string and a byte string?

The only thing that a computer can store is bytes.

To store anything in a computer, you must first encode it, i.e. convert it to bytes. For example:

  • If you want to store music, you must first encode it using MP3, WAV, etc.
  • If you want to store a picture, you must first encode it using PNG, JPEG, etc.
  • If you want to store text, you must first encode it using ASCII, UTF-8, etc.

MP3, WAV, PNG, JPEG, ASCII and UTF-8 are examples of encodings. An encoding is a format to represent audio, images, text, etc in bytes.

In Python, a byte string is just that: a sequence of bytes. It isn't human-readable. Under the hood, everything must be converted to a byte string before it can be stored in a computer.

On the other hand, a character string, often just called a "string", is a sequence of characters. It is human-readable. A character string can't be directly stored in a computer, it has to be encoded first (converted into a byte string). There are multiple encodings through which a character string can be converted into a byte string, such as ASCII and UTF-8.

'I am a string'.encode('ASCII')

The above Python code will encode the string 'I am a string' using the encoding ASCII. The result of the above code will be a byte string. If you print it, Python will represent it as b'I am a string'. Remember, however, that byte strings aren't human-readable, it's just that Python decodes them from ASCII when you print them. In Python, a byte string is represented by a b, followed by the byte string's ASCII representation.

A byte string can be decoded back into a character string, if you know the encoding that was used to encode it.

b'I am a string'.decode('ASCII')

The above code will return the original string 'I am a string'.

Encoding and decoding are inverse operations. Everything must be encoded before it can be written to disk, and it must be decoded before it can be read by a human.

Service Reference Error: Failed to generate code for the service reference

Restarting Visual Studio did the trick for me. I am using VS 2015.

MVVM Passing EventArgs As Command Parameter

I know this is a fairly old question, but I ran into the same problem today and wasn't too interested in referencing all of MVVMLight just so I can use event triggers with event args. I have used MVVMLight in the past and it's a great framework, but I just don't want to use it for my projects any more.

What I did to resolve this problem was create an ULTRA minimal, EXTREMELY adaptable custom trigger action that would allow me to bind to the command and provide an event args converter to pass on the args to the command's CanExecute and Execute functions. You don't want to pass the event args verbatim, as that would result in view layer types being sent to the view model layer (which should never happen in MVVM).

Here is the EventCommandExecuter class I came up with:

public class EventCommandExecuter : TriggerAction<DependencyObject>
{
    #region Constructors

    public EventCommandExecuter()
        : this(CultureInfo.CurrentCulture)
    {
    }

    public EventCommandExecuter(CultureInfo culture)
    {
        Culture = culture;
    }

    #endregion

    #region Properties

    #region Command

    public ICommand Command
    {
        get { return (ICommand)GetValue(CommandProperty); }
        set { SetValue(CommandProperty, value); }
    }

    public static readonly DependencyProperty CommandProperty =
        DependencyProperty.Register("Command", typeof(ICommand), typeof(EventCommandExecuter), new PropertyMetadata(null));

    #endregion

    #region EventArgsConverterParameter

    public object EventArgsConverterParameter
    {
        get { return (object)GetValue(EventArgsConverterParameterProperty); }
        set { SetValue(EventArgsConverterParameterProperty, value); }
    }

    public static readonly DependencyProperty EventArgsConverterParameterProperty =
        DependencyProperty.Register("EventArgsConverterParameter", typeof(object), typeof(EventCommandExecuter), new PropertyMetadata(null));

    #endregion

    public IValueConverter EventArgsConverter { get; set; }

    public CultureInfo Culture { get; set; }

    #endregion

    protected override void Invoke(object parameter)
    {
        var cmd = Command;

        if (cmd != null)
        {
            var param = parameter;

            if (EventArgsConverter != null)
            {
                param = EventArgsConverter.Convert(parameter, typeof(object), EventArgsConverterParameter, CultureInfo.InvariantCulture);
            }

            if (cmd.CanExecute(param))
            {
                cmd.Execute(param);
            }
        }
    }
}

This class has two dependency properties, one to allow binding to your view model's command, the other allows you to bind the source of the event if you need it during event args conversion. You can also provide culture settings if you need to (they default to the current UI culture).

This class allows you to adapt the event args so that they may be consumed by your view model's command logic. However, if you want to just pass the event args on verbatim, simply don't specify an event args converter.

The simplest usage of this trigger action in XAML is as follows:

<i:Interaction.Triggers>
    <i:EventTrigger EventName="NameChanged">
        <cmd:EventCommandExecuter Command="{Binding Path=Update, Mode=OneTime}" EventArgsConverter="{x:Static c:NameChangedArgsToStringConverter.Default}"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

If you needed access to the source of the event, you would bind to the owner of the event

<i:Interaction.Triggers>
    <i:EventTrigger EventName="NameChanged">
        <cmd:EventCommandExecuter 
            Command="{Binding Path=Update, Mode=OneTime}" 
            EventArgsConverter="{x:Static c:NameChangedArgsToStringConverter.Default}"
            EventArgsConverterParameter="{Binding ElementName=SomeEventSource, Mode=OneTime}"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

(this assumes that the XAML node you're attaching the triggers to has been assigned x:Name="SomeEventSource"

This XAML relies on importing some required namespaces

xmlns:cmd="clr-namespace:MyProject.WPF.Commands"
xmlns:c="clr-namespace:MyProject.WPF.Converters"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"

and creating an IValueConverter (called NameChangedArgsToStringConverter in this case) to handle the actual conversion logic. For basic converters I usually create a default static readonly converter instance, which I can then reference directly in XAML as I have done above.

The benefit of this solution is that you really only need to add a single class to any project to use the interaction framework much the same way that you would use it with InvokeCommandAction. Adding a single class (of about 75 lines) should be much more preferable to an entire library to accomplish identical results.

NOTE

this is somewhat similar to the answer from @adabyron but it uses event triggers instead of behaviours. This solution also provides an event args conversion ability, not that @adabyron's solution could not do this as well. I really don't have any good reason why I prefer triggers to behaviours, just a personal choice. IMO either strategy is a reasonable choice.

How do I correct the character encoding of a file?

I found this question when searching for a solution to a code page issue i had with Chinese characters, but in the end my problem was just an issue with Windows not displaying them correctly in the UI.

In case anyone else has that same issue, you can fix it simply by changing the local in windows to China and then back again.

I found the solution here:

http://answers.microsoft.com/en-us/windows/forum/windows_7-desktop/how-can-i-get-chinesejapanese-characters-to/fdb1f1da-b868-40d1-a4a4-7acadff4aafa?page=2&auth=1

Also upvoted Gabriel's answer as looking at the data in notepad++ was what tipped me off about windows.

Communication between multiple docker-compose projects

version: '2'
services:
  bot:
    build: .
    volumes:
      - '.:/home/node'
      - /home/node/node_modules
    networks:
      - my-rede
    mem_limit: 100m
    memswap_limit: 100m
    cpu_quota: 25000
    container_name: 236948199393329152_585042339404185600_bot
    command: node index.js
    environment:
      NODE_ENV: production
networks:
  my-rede:
    external:
      name: name_rede_externa

Calendar date to yyyy-MM-dd format in java

I found this code where date is compared in a format to compare with date field in database...may be this might be helpful to you...

When you convert the string to date using simpledateformat, it is hard to compare with the Date field in mysql databases.

So convert the java string date in the format using select STR_to_DATE('yourdate','%m/%d/%Y') --> in this format, then you will get the exact date format of mysql date field.

http://javainfinite.com/java/java-convert-string-to-date-and-compare/

Best way to get whole number part of a Decimal number

You just need to cast it, as such:

int intPart = (int)343564564.4342

If you still want to use it as a decimal in later calculations, then Math.Truncate (or possibly Math.Floor if you want a certain behaviour for negative numbers) is the function you want.

Why does sudo change the PATH?

Er, it's not really a test if you don't add something to your path:

bill@bill-desktop:~$ ls -l /opt/pkg/bin
total 12
-rwxr-xr-x 1 root root   28 2009-01-22 18:58 foo
bill@bill-desktop:~$ which foo
/opt/pkg/bin/foo
bill@bill-desktop:~$ sudo su
root@bill-desktop:/home/bill# which foo
root@bill-desktop:/home/bill# 

Add element to a list In Scala

Since you want to append elements to existing list, you can use var List[Int] and then keep on adding elements to the same list. Note -> You have to make sure that you insert an element into existing list as follows:-

var l: List[int] = List() // creates an empty list

l = 3 :: l // adds 3 to the head of the list

l = 4 :: l // makes int 4 as the head of the list

// Now when you will print l, you will see two elements in the list ( 4, 3)

How to correctly use the extern keyword in C

If each file in your program is first compiled to an object file, then the object files are linked together, you need extern. It tells the compiler "This function exists, but the code for it is somewhere else. Don't panic."

Import MySQL database into a MS SQL Server

I suggest you to use mysqldump like so:

mysqldump --compatible=mssql

phpMyAdmin is still a web-app and could potentially have some limitations for large databases (script execution time, allocatable memory and so on).

ImportError: No module named matplotlib.pyplot

I had a similar issue that I resolved and here is my issue:

I set everything up on python3 but I was using python to call my file for example: I was typing "python mnist.py" ...since I have everything on python3 it was thinking I was trying to use python 2.7

The correction: "python3 mnist.py" - the 3 made all the difference

I'm by no means an expert in python or pip, but there is definitely a difference between pip and pip3 (pip is tied to python 2.7) (pip3 is tied to python 3.6)

so when installing for 2.7 do: pip install when installing for 3.6 do: pip3 install

and when running your code for 2.7 do: python when running your code for 3.6 do: python3

I hope this helps someone!

MySQL - How to parse a string value to DATETIME format inside an INSERT statement?

Use MySQL's STR_TO_DATE() function to parse the string that you're attempting to insert:

INSERT INTO tblInquiry (fldInquiryReceivedDateTime) VALUES
  (STR_TO_DATE('5/15/2012 8:06:26 AM', '%c/%e/%Y %r'))

How do I do a HTTP GET in Java?

If you want to stream any webpage, you can use the method below.

import java.io.*;
import java.net.*;

public class c {

   public static String getHTML(String urlToRead) throws Exception {
      StringBuilder result = new StringBuilder();
      URL url = new URL(urlToRead);
      HttpURLConnection conn = (HttpURLConnection) url.openConnection();
      conn.setRequestMethod("GET");
      try (var reader = new BufferedReader(
                  new InputStreamReader(conn.getInputStream()))) {
          for (String line; (line = reader.readLine()) != null; ) {
              result.append(line);
          }
      }
      return result.toString();
   }

   public static void main(String[] args) throws Exception
   {
     System.out.println(getHTML(args[0]));
   }
}

What's the difference between Thread start() and Runnable run()

If you do run() in main method, the thread of main method will invoke the run method instead of the thread you require to run.

The start() method creates new thread and for which the run() method has to be done

Undefined function mysql_connect()

My guess is your PHP installation wasn't compiled with MySQL support.

Check your configure command (php -i | grep mysql). You should see something like '--with-mysql=shared,/usr'.

You can check for complete instructions at http://php.net/manual/en/mysql.installation.php. Although, I would rather go with the solution proposed by @wanovak.

Still, I think you need MySQL support in order to use PDO.

Google server putty connect 'Disconnected: No supported authentication methods available (server sent: publickey)

Apparently running sudo chmod -R a+rw on your home folder causes this to happen as well.

HTTP Error 500.19 and error code : 0x80070021

I also was getting the same problem but after brain storming with IIS and google for many hours. I found out the solution. This error is because some settings are disabled in IIS applicationHost.config.

Below are the steps to solution:

  1. Go to C:\Windows\System32\inetsrv\config\applicationHost.config and open in notepad
  2. Change the following key value present in

    • <section name="handlers" overrideModeDefault="Deny" /> change this value from "Deny" to "Allow"

    • <section name="modules" allowDefinition="MachineToApplication" overrideModeDefault="Deny" /> change this value from "Deny" to "Allow"

It worked for me.

Trim spaces from start and end of string

Note: As of 2015, all major browsers (including IE>=9) support String.prototype.trim(). This means that for most use cases simply doing str.trim() is the best way of achieving what the question asks.


Steven Levithan analyzed many different implementation of trim in Javascript in terms of performance.

His recommendation is:

function trim1 (str) {
    return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '');
}

for "general-purpose implementation which is fast cross-browser", and

function trim11 (str) {
    str = str.replace(/^\s+/, '');
    for (var i = str.length - 1; i >= 0; i--) {
        if (/\S/.test(str.charAt(i))) {
            str = str.substring(0, i + 1);
            break;
        }
    }
    return str;
}

"if you want to handle long strings exceptionally fast in all browsers".

References

I have Python on my Ubuntu system, but gcc can't find Python.h

I found the answer in ubuntuforums (ubuntuforums), you can just add this to your gcc '$(python-config --includes)'

gcc $(python-config --includes) urfile.c

Difference between BYTE and CHAR in column datatypes

I am not sure since I am not an Oracle user, but I assume that the difference lies when you use multi-byte character sets such as Unicode (UTF-16/32). In this case, 11 Bytes could account for less than 11 characters.

Also those field types might be treated differently in regard to accented characters or case, for example 'binaryField(ete) = "été"' will not match while 'charField(ete) = "été"' might (again not sure about Oracle).

NLS_NUMERIC_CHARACTERS setting for decimal

Jaanna, the session parameters in Oracle SQL Developer are dependent on your client computer, while the NLS parameters on PL/SQL is from server.

For example the NLS_NUMERIC_CHARACTERS on client computer can be ',.' while it's '.,' on server.

So when you run script from PL/SQL and Oracle SQL Developer the decimal separator can be completely different for the same script, unless you alter session with your expected NLS_NUMERIC_CHARACTERS in the script.

One way to easily test your session parameter is to do:

select to_number(5/2) from dual;

Why is an OPTIONS request sent and can I disable it?

Have gone through this issue, below is my conclusion to this issue and my solution.

According to the CORS strategy (highly recommend you read about it) You can't just force the browser to stop sending OPTIONS request if it thinks it needs to.

There are two ways you can work around it:

  1. Make sure your request is a "simple request"
  2. Set Access-Control-Max-Age for the OPTIONS request

Simple request

A simple cross-site request is one that meets all the following conditions:

The only allowed methods are:

  • GET
  • HEAD
  • POST

Apart from the headers set automatically by the user agent (e.g. Connection, User-Agent, etc.), the only headers which are allowed to be manually set are:

  • Accept
  • Accept-Language
  • Content-Language
  • Content-Type

The only allowed values for the Content-Type header are:

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

A simple request will not cause a pre-flight OPTIONS request.

Set a cache for the OPTIONS check

You can set a Access-Control-Max-Age for the OPTIONS request, so that it will not check the permission again until it is expired.

Access-Control-Max-Age gives the value in seconds for how long the response to the preflight request can be cached for without sending another preflight request.

Limitation Noted

  • For Chrome, the maximum seconds for Access-Control-Max-Age is 600 which is 10 minutes, according to chrome source code
  • Access-Control-Max-Age only works for one resource every time, for example, GET requests with same URL path but different queries will be treated as different resources. So the request to the second resource will still trigger a preflight request.

Binding to static property

If you are using local resources you can refer to them as below:

<TextBlock Text="{Binding Source={x:Static prop:Resources.PerUnitOfMeasure}}" TextWrapping="Wrap" TextAlignment="Center"/>

How to put/get multiple JSONObjects to JSONArray?

From android API Level 19, when I want to instance JSONArray object I put JSONObject directly as parameter like below:

JSONArray jsonArray=new JSONArray(jsonObject);

JSONArray has constructor to accept object.

What are passive event listeners?

Passive event listeners are an emerging web standard, new feature shipped in Chrome 51 that provide a major potential boost to scroll performance. Chrome Release Notes.

It enables developers to opt-in to better scroll performance by eliminating the need for scrolling to block on touch and wheel event listeners.

Problem: All modern browsers have a threaded scrolling feature to permit scrolling to run smoothly even when expensive JavaScript is running, but this optimization is partially defeated by the need to wait for the results of any touchstart and touchmove handlers, which may prevent the scroll entirely by calling preventDefault() on the event.

Solution: {passive: true}

By marking a touch or wheel listener as passive, the developer is promising the handler won't call preventDefault to disable scrolling. This frees the browser up to respond to scrolling immediately without waiting for JavaScript, thus ensuring a reliably smooth scrolling experience for the user.

document.addEventListener("touchstart", function(e) {
    console.log(e.defaultPrevented);  // will be false
    e.preventDefault();   // does nothing since the listener is passive
    console.log(e.defaultPrevented);  // still false
}, Modernizr.passiveeventlisteners ? {passive: true} : false);

DOM Spec , Demo Video , Explainer Doc

History or log of commands executed in Git

A log of your commands may be available in your shell history.

history

If seeing the list of executed commands fly by isn't for you, export the list into a file.

history > path/to/file

You can restrict the exported dump to only show commands with "git" in them by piping it with grep

history | grep "git " > path/to/file

The history may contain lines formatted as such

518  git status -s
519  git commit -am "injects sriracha to all toppings, as required"

Using the number you can re-execute the command with an exclamation mark

$ !518
git status -s

Include another HTML file in a HTML file

I have one more solution to do this

Using Ajax in javascript

here is the explained code in Github repo https://github.com/dupinder/staticHTML-Include

basic idea is:

index.html

<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8'>
    <meta http-equiv='X-UA-Compatible' content='IE=edge'>
    <title>Page Title</title>
    <meta name='viewport' content='width=device-width, initial-scale=1'>
    <script src='main.js'></script>


</head>
<body>
    <header></header>

    <footer></footer>
</body>
</html>

main.js

fetch("./header.html")
  .then(response => {
    return response.text()
  })
  .then(data => {
    document.querySelector("header").innerHTML = data;
  });

fetch("./footer.html")
  .then(response => {
    return response.text()
  })
  .then(data => {
    document.querySelector("footer").innerHTML = data;
  });

Android XML Percent Symbol

You can escape the % in xml with %%, but you need to set the text in code, not in layout xml.

What is the Sign Off feature in Git for?

Sign-off is a line at the end of the commit message which certifies who is the author of the commit. Its main purpose is to improve tracking of who did what, especially with patches.

Example commit:

Add tests for the payment processor.

Signed-off-by: Humpty Dumpty <[email protected]>

It should contain the user real name if used for an open-source project.

If branch maintainer need to slightly modify patches in order to merge them, he could ask the submitter to rediff, but it would be counter-productive. He can adjust the code and put his sign-off at the end so the original author still gets credit for the patch.

Add tests for the payment processor.

Signed-off-by: Humpty Dumpty <[email protected]>

[Project Maintainer: Renamed test methods according to naming convention.]
Signed-off-by: Project Maintainer <[email protected]>

Source: http://gerrit.googlecode.com/svn/documentation/2.0/user-signedoffby.html

Why is __dirname not defined in node REPL?

I was running a script from batch file as SYSTEM user and all variables like process.cwd() , path.resolve() and all other methods would give me path to C:\Windows\System32 folder instead of actual path. During experiments I noticed that when an error is thrown the stack contains a true path to the node file.

Here's a very hacky way to get true path by triggering an error and extracting path from e.stack. Do not use.

// this should be the name of currently executed file
const currentFilename = 'index.js';

function veryHackyGetFolder() {
  try {
    throw new Error();
  } catch(e) {
    const fullMsg = e.stack.toString();
    const beginning = fullMsg.indexOf('file:///') + 8;
    const end = fullMsg.indexOf('\/' + currentFilename);
    const dir = fullMsg.substr(beginning, end - beginning).replace(/\//g, '\\');
    return dir;
  }
}

Usage

const dir = veryHackyGetFolder();

How do I run Java .class files?

You have to put java in lower case and you have to add .class!

java HelloWorld2.class

Inserting data to table (mysqli insert)

Warning: Never ever refer to w3schools for learning purposes. They have so many mistakes in their tutorials.

According to the mysqli_query documentation, the first parameter must be a connection string:

$link = mysqli_connect("localhost","root","","web_table");

mysqli_query($link,"INSERT INTO web_formitem (`ID`, `formID`, `caption`, `key`, `sortorder`, `type`, `enabled`, `mandatory`, `data`)
VALUES (105, 7, 'Tip izdelka (6)', 'producttype_6', 42, 5, 1, 0, 0)") 
or die(mysqli_error($link));

Note: Add backticks ` for column names in your insert query as some of your column names are reserved words.

Counting the number of files in a directory using Java

Since Java 8, you can do that in three lines:

try (Stream<Path> files = Files.list(Paths.get("your/path/here"))) {
    long count = files.count();
}

Regarding the 5000 child nodes and inode aspects:

This method will iterate over the entries but as Varkhan suggested you probably can't do better besides playing with JNI or direct system commands calls, but even then, you can never be sure these methods don't do the same thing!

However, let's dig into this a little:

Looking at JDK8 source, Files.list exposes a stream that uses an Iterable from Files.newDirectoryStream that delegates to FileSystemProvider.newDirectoryStream.

On UNIX systems (decompiled sun.nio.fs.UnixFileSystemProvider.class), it loads an iterator: A sun.nio.fs.UnixSecureDirectoryStream is used (with file locks while iterating through the directory).

So, there is an iterator that will loop through the entries here.

Now, let's look to the counting mechanism.

The actual count is performed by the count/sum reducing API exposed by Java 8 streams. In theory, this API can perform parallel operations without much effort (with multihtreading). However the stream is created with parallelism disabled so it's a no go...

The good side of this approach is that it won't load the array in memory as the entries will be counted by an iterator as they are read by the underlying (Filesystem) API.

Finally, for the information, conceptually in a filesystem, a directory node is not required to hold the number of the files that it contains, it can just contain the list of it's child nodes (list of inodes). I'm not an expert on filesystems, but I believe that UNIX filesystems work just like that. So you can't assume there is a way to have this information directly (i.e: there can always be some list of child nodes hidden somewhere).

How to put comments in Django templates

In contrast to traditional html comments like this:

<!-- not so secret secrets -->

Django template comments are not rendered in the final html. So you can feel free to stuff implementation details in there like so:

Multi-line:

{% comment %}
    The other half of the flexbox is defined 
    in a different file `sidebar.html`
    as <div id="sidebar-main">.
{% endcomment %}

Single line:

{# jquery latest #}

{#
    beware, this won't be commented out... 
    actually renders as regular body text on the page
#}

I find single line comments especially helpful for <a href="{% url 'view_name' %}" views that have not been created yet.

Real escape string and PDO

PDO offers an alternative designed to replace mysql_escape_string() with the PDO::quote() method.

Here is an excerpt from the PHP website:

<?php
    $conn = new PDO('sqlite:/home/lynn/music.sql3');

    /* Simple string */
    $string = 'Nice';
    print "Unquoted string: $string\n";
    print "Quoted string: " . $conn->quote($string) . "\n";
?>

The above code will output:

Unquoted string: Nice
Quoted string: 'Nice'

Python dictionary: are keys() and values() always the same order?

I wasn't satisfied with these answers since I wanted to ensure the exported values had the same ordering even when using different dicts.

Here you specify the key order upfront, the returned values will always have the same order even if the dict changes, or you use a different dict.

keys = dict1.keys()
ordered_keys1 = [dict1[cur_key] for cur_key in keys]
ordered_keys2 = [dict2[cur_key] for cur_key in keys]

How do I wait for an asynchronously dispatched block to finish?

dispatch_semaphore_t sema = dispatch_semaphore_create(0);
[object blockToExecute:^{
    // ... your code to execute
    dispatch_semaphore_signal(sema);
}];

while (dispatch_semaphore_wait(semaphore, DISPATCH_TIME_NOW)) {
    [[NSRunLoop currentRunLoop]
        runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0]];
}

This did it for me.

Append data to a POST NSURLRequest

Any one looking for a swift solution

let url = NSURL(string: "http://www.apple.com/")
let request = NSMutableURLRequest(URL: url!)
request.HTTPBody = "company=Locassa&quality=AWESOME!".dataUsingEncoding(NSUTF8StringEncoding)

Why do I get "warning longer object length is not a multiple of shorter object length"?

I had a similar issue and using %in% operator instead of the == (equality) operator was the solution:

# %in%

Hope it helps.

ImportError: No module named sqlalchemy

Probably a stupid mistake; but, I experienced this problem and the issue turned out to be that "pip3 install sqlalchemy" installs libraries in user specific directories.

On my Linux machine, I was logged in as user1 executing a python script in user2's directory. I installed sqlalchemy as user1 and it by default placed the files in user1's directory. After installing sqlalchemy in user2's directory the problem went away.

How to write to a JSON file in the correct format

To make this work on Ubuntu Linux:

  1. I installed the Ubuntu package ruby-json:

    apt-get install ruby-json
    
  2. I wrote the script in ${HOME}/rubybin/jsonDEMO

  3. $HOME/.bashrc included:

    ${HOME}/rubybin:${PATH}
    

(On this occasion I also typed the above on the bash command line.)

Then it worked when I entered on the command line:

jsonDemo

JavaScript Number Split into individual digits

_x000D_
_x000D_
// Split positive integer n < 1e21 into digits:_x000D_
function digits(n) {_x000D_
  return Array.from(String(n), Number);_x000D_
}_x000D_
_x000D_
// Example:_x000D_
console.log(digits(1234)); // [1, 2, 3, 4]
_x000D_
_x000D_
_x000D_

Split a python list into other "sublists" i.e smaller lists

chunks = [data[100*i:100*(i+1)] for i in range(len(data)/100 + 1)]

This is equivalent to the accepted answer. For example, shortening to batches of 10 for readability:

data = range(35)
print [data[x:x+10] for x in xrange(0, len(data), 10)]
print [data[10*i:10*(i+1)] for i in range(len(data)/10 + 1)]

Outputs:

[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12, 13, 14, 15, 16, 17, 18, 19], [20, 21, 22, 23, 24, 25, 26, 27, 28, 29], [30, 31, 32, 33, 34]]
[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12, 13, 14, 15, 16, 17, 18, 19], [20, 21, 22, 23, 24, 25, 26, 27, 28, 29], [30, 31, 32, 33, 34]]

Interface vs Base class

An inheritor of a base class should have an "is a" relationship. Interface represents An "implements a" relationship. So only use a base class when your inheritors will maintain the is a relationship.

Change text color with Javascript?

<div id="about">About Snakelane</div>

<input type="image" src="http://www.blakechris.com/snakelane/assets/about.png" onclick="init()" id="btn">
<script>
var about;   
function init() { 
    about = document.getElementById("about");
    about.style.color = 'blue';
}

Open a selected file (image, pdf, ...) programmatically from my Android Application?

Use this code ,which helped me to open all types of files ...

 private void openFile(File url) {

    try {

        Uri uri = Uri.fromFile(url);

        Intent intent = new Intent(Intent.ACTION_VIEW);
        if (url.toString().contains(".doc") || url.toString().contains(".docx")) {
            // Word document
            intent.setDataAndType(uri, "application/msword");
        } else if (url.toString().contains(".pdf")) {
            // PDF file
            intent.setDataAndType(uri, "application/pdf");
        } else if (url.toString().contains(".ppt") || url.toString().contains(".pptx")) {
            // Powerpoint file
            intent.setDataAndType(uri, "application/vnd.ms-powerpoint");
        } else if (url.toString().contains(".xls") || url.toString().contains(".xlsx")) {
            // Excel file
            intent.setDataAndType(uri, "application/vnd.ms-excel");
        } else if (url.toString().contains(".zip")) {
            // ZIP file
            intent.setDataAndType(uri, "application/zip");
        } else if (url.toString().contains(".rar")){
            // RAR file
            intent.setDataAndType(uri, "application/x-rar-compressed");
        } else if (url.toString().contains(".rtf")) {
            // RTF file
            intent.setDataAndType(uri, "application/rtf");
        } else if (url.toString().contains(".wav") || url.toString().contains(".mp3")) {
            // WAV audio file
            intent.setDataAndType(uri, "audio/x-wav");
        } else if (url.toString().contains(".gif")) {
            // GIF file
            intent.setDataAndType(uri, "image/gif");
        } else if (url.toString().contains(".jpg") || url.toString().contains(".jpeg") || url.toString().contains(".png")) {
            // JPG file
            intent.setDataAndType(uri, "image/jpeg");
        } else if (url.toString().contains(".txt")) {
            // Text file
            intent.setDataAndType(uri, "text/plain");
        } else if (url.toString().contains(".3gp") || url.toString().contains(".mpg") ||
                url.toString().contains(".mpeg") || url.toString().contains(".mpe") || url.toString().contains(".mp4") || url.toString().contains(".avi")) {
            // Video files
            intent.setDataAndType(uri, "video/*");
        } else {
            intent.setDataAndType(uri, "*/*");
        }

        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    } catch (ActivityNotFoundException e) {
        Toast.makeText(context, "No application found which can open the file", Toast.LENGTH_SHORT).show();
    }
}

node.js string.replace doesn't work?

If you just want to clobber all of the instances of a substring out of a string without using regex you can using:

    var replacestring = "A B B C D"
    const oldstring = "B";
    const newstring = "E";
    while (replacestring.indexOf(oldstring) > -1) {
        replacestring = replacestring.replace(oldstring, newstring);
    }        
    //result: "A E E C D"

Import existing Gradle Git project into Eclipse

Open eclipse and right click in the package explorer ? import Select gradle Browse to the location where you checked out Click “Build Model” Select all the projects and hit finish

Multiple "order by" in LINQ

use the following line on your DataContext to log the SQL activity on the DataContext to the console - then you can see exactly what your linq statements are requesting from the database:

_db.Log = Console.Out

The following LINQ statements:

var movies = from row in _db.Movies 
             orderby row.CategoryID, row.Name
             select row;

AND

var movies = _db.Movies.OrderBy(m => m.CategoryID).ThenBy(m => m.Name);

produce the following SQL:

SELECT [t0].ID, [t0].[Name], [t0].CategoryID
FROM [dbo].[Movies] as [t0]
ORDER BY [t0].CategoryID, [t0].[Name]

Whereas, repeating an OrderBy in Linq, appears to reverse the resulting SQL output:

var movies = from row in _db.Movies 
             orderby row.CategoryID
             orderby row.Name
             select row;

AND

var movies = _db.Movies.OrderBy(m => m.CategoryID).OrderBy(m => m.Name);

produce the following SQL (Name and CategoryId are switched):

SELECT [t0].ID, [t0].[Name], [t0].CategoryID
FROM [dbo].[Movies] as [t0]
ORDER BY [t0].[Name], [t0].CategoryID

what is the use of xsi:schemaLocation?

The Java XML parser that spring uses will read the schemaLocation values and try to load them from the internet, in order to validate the XML file. Spring, in turn, intercepts those load requests and serves up versions from inside its own JAR files.

If you omit the schemaLocation, then the XML parser won't know where to get the schema in order to validate the config.

Git reset --hard and push to remote repository

Instead of fixing your "master" branch, it's way easier to swap it with your "desired-master" by renaming the branches. See https://stackoverflow.com/a/2862606/2321594. This way you wouldn't even leave any trace of multiple revert logs.

how to read System environment variable in Spring applicationContext

In your bean definition, make sure to include "searchSystemEnvironment" and set it to "true". And if you're using it to build a path to a file, specify it as a file:/// url.

So for example, if you have a config file located in

/testapp/config/my.app.config.properties

then set an environment variable like so:

MY_ENV_VAR_PATH=/testapp/config

and your app can load the file using a bean definition like this:

e.g.

<bean class="org.springframework.web.context.support.ServletContextPropertyPlaceholderConfigurer">
    <property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
    <property name="searchSystemEnvironment" value="true" />
    <property name="searchContextAttributes" value="true" />
    <property name="contextOverride" value="true" />
    <property name="ignoreResourceNotFound" value="true" />
    <property name="locations">
        <list>
            <value>file:///${MY_ENV_VAR_PATH}/my.app.config.properties</value>
        </list>
    </property>
</bean>

NPM: npm-cli.js not found when running npm

In my case, I was using nvm-windows 1.1.6 , and I updated my nodejs version using nvm install latest, which eventually told me that nodejs and npm are installed, however when I tried to do npm install, I received

Error: Cannot find module 'C:\Program Files\nodejs\node_modules\npm\bin\npm-cli.js'

upon checking nvm-windows structure, I found that C:\Program Files\nodejs was symlinked to %APPDATA%\nvm\NODE_VERSION, (NODE_VERSION was v9.7.1 in my case) which has the folder node_modules having nothing inside, caused this error. The solution was to copy the npm folder from one of my previous versions' node_modules folder and paste it in. I then updated my npm with npm install npm@next -g and everything started working again.

ERROR 2006 (HY000): MySQL server has gone away

This is more of a rare issue but I have seen this if someone has copied the entire /var/lib/mysql directory as a way of migrating their DB to another server. The reason it doesn't work is because the database was running and using log files. It doesn't work sometimes if there are logs in /var/log/mysql. The solution is to copy the /var/log/mysql files as well.

TypeError: $(...).DataTable is not a function

There can be two reasons for that error:

First

You are loding jQuery.DataTables.js before jquery.js so for that :-

You need to load jQuery.js before you load jQuery.DataTables.js

Second

You are using two versions of jQuery.js on the same page so for that :-

Try to use the higher version and make sure both links have same version of jQuery

Increase days to php current Date()

php supports c style date functions. You can add or substract date-periods with English-language style phrases via the strtotime function. examples...

$Today=date('y:m:d');

// add 3 days to date
$NewDate=Date('y:m:d', strtotime('+3 days'));

// subtract 3 days from date
$NewDate=Date('y:m:d', strtotime('-3 days'));

// PHP returns last sunday's date
$NewDate=Date('y:m:d', strtotime('Last Sunday'));

// One week from last sunday
$NewDate=Date('y:m:d', strtotime('+7 days Last Sunday'));

or

<select id="date_list" class="form-control" style="width:100%;">
<?php
$max_dates = 15;
$countDates = 0;
while ($countDates < $max_dates) {
    $NewDate=Date('F d, Y', strtotime("+".$countDates." days"));
    echo "<option>" . $NewDate . "</option>";
    $countDates += 1;
}
?>

Exception : javax.net.ssl.SSLPeerUnverifiedException: peer not authenticated

In my case I was using a JDK 8 client and the server was using insecure old ciphers. The server is Apache and I added this line to the Apache config:

SSLCipherSuite ALL:!ADH:RC4+RSA:+HIGH:!MEDIUM:!LOW:!SSLv2:!EXPORT

You should use a tool like this to verify your SSL configuration is currently secure: https://www.ssllabs.com/ssltest/analyze.html

Rename multiple files in cmd

I tried pasting Endoro's command (Thanks Endoro) directly into the command prompt to add a prefix to files but encountered an error. Solution was to reduce %% to %, so:

for /f "delims=" %i in ('dir /b /a-d *.*') do ren "%~i" "Service.Enviro.%~ni%~xi"

ng serve not detecting file changes automatically

Giving full permission for the project folder worked for me

running multiple bash commands with subprocess

import subprocess
cmd = "vsish -e ls /vmkModules/lsom/disks/  | cut -d '/' -f 1  | while read diskID  ; do echo $diskID; vsish -e cat /vmkModules/lsom/disks/$diskID/virstoStats | grep -iE 'Delete pending |trims currently queued' ;  echo '====================' ;done ;"


def subprocess_cmd(command):
    process = subprocess.Popen(command,stdout=subprocess.PIPE, shell=True)
    proc_stdout = process.communicate()[0].strip()
    for line in proc_stdout.decode().split('\n'):
        print (line)

subprocess_cmd(cmd)

MySQL: Error Code: 1118 Row size too large (> 8126). Changing some columns to TEXT or BLOB

Changing into MyISAM is not the solution. For innodb following worked for me.

set followings on my.cnf

innodb_strict_mode=0

DTO and DAO concepts and MVC

DTO is an abbreviation for Data Transfer Object, so it is used to transfer the data between classes and modules of your application.

  • DTO should only contain private fields for your data, getters, setters, and constructors.
  • DTO is not recommended to add business logic methods to such classes, but it is OK to add some util methods.

DAO is an abbreviation for Data Access Object, so it should encapsulate the logic for retrieving, saving and updating data in your data storage (a database, a file-system, whatever).

Here is an example of how the DAO and DTO interfaces would look like:

interface PersonDTO {
    String getName();
    void setName(String name);
    //.....
}

interface PersonDAO {
    PersonDTO findById(long id);
    void save(PersonDTO person);
    //.....
}

The MVC is a wider pattern. The DTO/DAO would be your model in the MVC pattern.
It tells you how to organize the whole application, not just the part responsible for data retrieval.

As for the second question, if you have a small application it is completely OK, however, if you want to follow the MVC pattern it would be better to have a separate controller, which would contain the business logic for your frame in a separate class and dispatch messages to this controller from the event handlers.
This would separate your business logic from the view.

How to change the commit author for one specific commit?

OPTIONAL: Make sure to stash your local changes if you don't want to send them to remote.

$ git status
$ git stash

Update the author for the last commit.

$ git log   // Old author in local and remote
$ git commit --amend --author="Author Name <[email protected]>"
$ git log   // New Author in local
$ git push origin <branch> --force-with-lease 
$ git log   // New Author in remote

Then, if you used git stash then recovers your staged changes

$ git stash pop
$ git status

Then, you should to update the configuration for the next commits of the current project.

$ git config user.name "Author Name"
$ git config user.email "<[email protected]>"

And check or also edit this with git config --edit


Clarification: In the rare case that you lose commits using $ ggpush -f you can recover them with reflog. Anyway using --force-with-lease you are protected even more than if you use only -f

GL

image processing to improve tesseract OCR accuracy

Text Recognition depends on a variety of factors to produce a good quality output. OCR output highly depends on the quality of input image. This is why every OCR engine provides guidelines regarding the quality of input image and its size. These guidelines help OCR engine to produce accurate results.

I have written a detailed article on image processing in python. Kindly follow the link below for more explanation. Also added the python source code to implement those process.

Please write a comment if you have a suggestion or better idea on this topic to improve it.

https://medium.com/cashify-engineering/improve-accuracy-of-ocr-using-image-preprocessing-8df29ec3a033

window.close() doesn't work - Scripts may close only the windows that were opened by it

The below code worked for me :)

window.open('your current page URL', '_self', '');
window.close();

Placeholder in IE9

HTML5 Placeholder jQuery Plugin
- by Mathias Bynens (a collaborator on HTML5 Boilerplate and jsPerf)

https://github.com/mathiasbynens/jquery-placeholder

Demo & Examples

http://mathiasbynens.be/demo/placeholder

p.s
I have used this plugin many times and it works a treat. Also it doesn't submit the placeholder text as a value when you submit your form (... a real pain I found with other plugins).

How to use a typescript enum value in an Angular2 ngSwitch statement

You can create a reference to the enum in your component class (I just changed the initial character to be lower-case) and then use that reference from the template (plunker):

import {Component} from 'angular2/core';

enum CellType {Text, Placeholder}
class Cell {
  constructor(public text: string, public type: CellType) {}
}
@Component({
  selector: 'my-app',
  template: `
    <div [ngSwitch]="cell.type">
      <div *ngSwitchCase="cellType.Text">
        {{cell.text}}
      </div>
      <div *ngSwitchCase="cellType.Placeholder">
        Placeholder
      </div>
    </div>
    <button (click)="setType(cellType.Text)">Text</button>
    <button (click)="setType(cellType.Placeholder)">Placeholder</button>
  `,
})
export default class AppComponent {

  // Store a reference to the enum
  cellType = CellType;
  public cell: Cell;

  constructor() {
    this.cell = new Cell("Hello", CellType.Text)
  }

  setType(type: CellType) {
    this.cell.type = type;
  }
}

java.net.SocketException: Connection reset

Check your server's Java version. Happened to me because my Weblogic 10.3.6 was on JDK 1.7.0_75 which was on TLSv1. The rest endpoint I was trying to consume was shutting down anything below TLSv1.2.

By default Weblogic was trying to negotiate the strongest shared protocol. See details here: Issues with setting https.protocols System Property for HTTPS connections.

I added verbose SSL logging to identify the supported TLS. This indicated TLSv1 was being used for the handshake.
-Djavax.net.debug=ssl:handshake:verbose:keymanager:trustmanager -Djava.security.debug=access:stack

I resolved this by pushing the feature out to our JDK8-compatible product, JDK8 defaults to TLSv1.2. For those restricted to JDK7, I also successfully tested a workaround for Java 7 by upgrading to TLSv1.2. I used this answer: How to enable TLS 1.2 in Java 7