Programs & Examples On #Businessworks

TIBCO ActiveMatrix BusinessWorks

How to find the Windows version from the PowerShell command line

I searched a lot to find out the exact version, because WSUS server shows the wrong version. The best is to get revision from UBR registry KEY.

    $WinVer = New-Object –TypeName PSObject
$WinVer | Add-Member –MemberType NoteProperty –Name Major –Value $(Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion' CurrentMajorVersionNumber).CurrentMajorVersionNumber
$WinVer | Add-Member –MemberType NoteProperty –Name Minor –Value $(Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion' CurrentMinorVersionNumber).CurrentMinorVersionNumber
$WinVer | Add-Member –MemberType NoteProperty –Name Build –Value $(Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion' CurrentBuild).CurrentBuild
$WinVer | Add-Member –MemberType NoteProperty –Name Revision –Value $(Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion' UBR).UBR
$WinVer

Get query from java.sql.PreparedStatement

A bit of a hack, but it works fine for me:

Integer id = 2;
String query = "SELECT * FROM table WHERE id = ?";
PreparedStatement statement = m_connection.prepareStatement( query );
statement.setObject( 1, value );
String statementText = statement.toString();
query = statementText.substring( statementText.indexOf( ": " ) + 2 );

How do I run a Python program?

if you dont want call filename.py you can add .PY to the PATHEXT, that way you will just call filename

Android Center text on canvas

If we are using Static layout

mStaticLayout = new StaticLayout(mText, mTextPaint, mTextWidth,
                Layout.Alignment.ALIGN_CENTER, 1.0f, 0, true);

Layout.Alignment.ALIGN_CENTER this will do the trick. Static layout also has got a lot of other advantages.

Reference:Android Documentation

/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.15' not found

In my case LD_LIBRARY_PATH had /usr/lib64 first before /usr/local/lib64. (I was builing llvm 3.9).
The new gcc compiler that I installed to compile llvm 3.9 had libraries using newer GLIBCXX libraries under /usr/local/lib64 So I fixed LD_LIBRARY_PATH for the linker to see /usr/local/lib64 first.
That solved this problem.

How to always show scrollbar

Simple and easy. Add this attribute to the ScrollBar:

android:fadeScrollbars="false"

Or you can do this in :

scrollView.setScrollbarFadingEnabled(false);

Or in :

scrollView.isScrollbarFadingEnabled = false

PHP: How to use array_filter() to filter array keys?

If you are looking for a method to filter an array by a string occurring in keys, you can use:

$mArray=array('foo'=>'bar','foo2'=>'bar2','fooToo'=>'bar3','baz'=>'nope');
$mSearch='foo';
$allowed=array_filter(
    array_keys($mArray),
    function($key) use ($mSearch){
        return stristr($key,$mSearch);
    });
$mResult=array_intersect_key($mArray,array_flip($allowed));

The result of print_r($mResult) is

Array ( [foo] => bar [foo2] => bar2 [fooToo] => bar3 )

An adaption of this answer that supports regular expressions

function array_preg_filter_keys($arr, $regexp) {
  $keys = array_keys($arr);
  $match = array_filter($keys, function($k) use($regexp) {
    return preg_match($regexp, $k) === 1;
  });
  return array_intersect_key($arr, array_flip($match));
}

$mArray = array('foo'=>'yes', 'foo2'=>'yes', 'FooToo'=>'yes', 'baz'=>'nope');

print_r(array_preg_filter_keys($mArray, "/^foo/i"));

Output

Array
(
    [foo] => yes
    [foo2] => yes
    [FooToo] => yes
)

How to delete/remove nodes on Firebase

Firebase.remove() like probably most Firebase methods is asynchronous, thus you have to listen to events to know when something happened:

parent = ref.parent()
parent.on('child_removed', function (snapshot) {
    // removed!
})
ref.remove()

According to Firebase docs it should work even if you lose network connection. If you want to know when the change has been actually synchronized with Firebase servers, you can pass a callback function to Firebase.remove method:

ref.remove(function (error) {
    if (!error) {
        // removed!
    }
}

create array from mysql query php

You could also make life easier using a wrapper, e.g. with ADODb:

$myarray=$db->GetCol("SELECT type FROM cars ".
    "WHERE owner=? and selling=0", 
    array($_SESSION['username']));

A good wrapper will do all your escaping for you too, making things easier to read.

How do I add an element to a list in Groovy?

From the documentation:

We can add to a list in many ways:

assert [1,2] + 3 + [4,5] + 6 == [1, 2, 3, 4, 5, 6]
assert [1,2].plus(3).plus([4,5]).plus(6) == [1, 2, 3, 4, 5, 6]
    //equivalent method for +
def a= [1,2,3]; a += 4; a += [5,6]; assert a == [1,2,3,4,5,6]
assert [1, *[222, 333], 456] == [1, 222, 333, 456]
assert [ *[1,2,3] ] == [1,2,3]
assert [ 1, [2,3,[4,5],6], 7, [8,9] ].flatten() == [1, 2, 3, 4, 5, 6, 7, 8, 9]

def list= [1,2]
list.add(3) //alternative method name
list.addAll([5,4]) //alternative method name
assert list == [1,2,3,5,4]

list= [1,2]
list.add(1,3) //add 3 just before index 1
assert list == [1,3,2]
list.addAll(2,[5,4]) //add [5,4] just before index 2
assert list == [1,3,5,4,2]

list = ['a', 'b', 'z', 'e', 'u', 'v', 'g']
list[8] = 'x'
assert list == ['a', 'b', 'z', 'e', 'u', 'v', 'g', null, 'x']

You can also do:

def myNewList = myList << "fifth"

How to get the first and last date of the current year?

The best way to get First Date and Last Date of a year Is

SELECT CAST(CAST(YEAR(DATEADD(YEAR,-1,GETDATE())) AS VARCHAR) + '-' + '01' + '-' + '01' AS DATE) FIRST_DATE
SELECT CAST(CAST(YEAR(DATEADD(YEAR,-1,GETDATE())) AS VARCHAR) + '-' + '12' + '-' + '31' AS DATE) LAST_DATE

Loading a .json file into c# program

As mentioned in the other answer I would recommend using json.NET. You can download the package using NuGet. Then to deserialize your json files into C# objects you can do something like;

   JsonSerializer serializer = new JsonSerializer();
   MyObject obj = serializer.Deserialize<MyObject>(File.ReadAllText(@".\path\to\json\config\file.json");

The above code assumes that you have something like

public class MyObject
{
    public string prop1 { get; set; };
    public string prop2 { get; set; };
}

And your json looks like;

{
      "prop1":"value1",
      "prop2":"value2"
}

I prefer using the generic deserialize method which will deserialize json into an object assuming that you provide it with a type who's definition matches the json's. If there are discrepancies between the two it could throw, or not set values, or just ignore things in the json, depends on what the problem is. If the json definition exactly matches the C# types definition then it just works.

Can I use jQuery to check whether at least one checkbox is checked?

if(jQuery('#frmTest input[type=checkbox]:checked').length) { … }

"document.getElementByClass is not a function"

document.querySelectorAll works pretty well and allows you to further narrow down your selection.

https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll

Where does Internet Explorer store saved passwords?

No guarantee, but I suspect IE uses the older Protected Storage API.

get next sequence value from database using hibernate

Your idea with the SequenceGenerator fake entity is good.

@Id
@GenericGenerator(name = "my_seq", strategy = "sequence", parameters = {
        @org.hibernate.annotations.Parameter(name = "sequence_name", value = "MY_CUSTOM_NAMED_SQN"),
})
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "my_seq")

It is important to use the parameter with the key name "sequence_name". Run a debugging session on the hibernate class SequenceStyleGenerator, the configure(...) method at the line final QualifiedName sequenceName = determineSequenceName( params, dialect, jdbcEnvironment ); to see more details about how the sequence name is computed by Hibernate. There are some defaults in there you could also use.

After the fake entity, I created a CrudRepository:

public interface SequenceRepository extends CrudRepository<SequenceGenerator, Long> {}

In the Junit, I call the save method of the SequenceRepository.

SequenceGenerator sequenceObject = new SequenceGenerator(); SequenceGenerator result = sequenceRepository.save(sequenceObject);

If there is a better way to do this (maybe support for a generator on any type of field instead of just Id), I would be more than happy to use it instead of this "trick".

How to calculate difference between two dates in oracle 11g SQL

Oracle DateDiff is from a different product, probably mysql (which is now owned by Oracle).

The difference between two dates (in oracle's usual database product) is in days (which can have fractional parts). Factor by 24 to get hours, 24*60 to get minutes, 24*60*60 to get seconds (that's as small as dates go). The math is 100% accurate for dates within a couple of hundred years or so. E.g. to get the date one second before midnight of today, you could say

select trunc(sysdate) - 1/24/60/60 from dual;

That means "the time right now", truncated to be just the date (i.e. the midnight that occurred this morning). Then it subtracts a number which is the fraction of 1 day that measures one second. That gives you the date from the previous day with the time component of 23:59:59.

How do I bind a WPF DataGrid to a variable number of columns?

I have found a blog article by Deborah Kurata with a nice trick how to show variable number of columns in a DataGrid:

Populating a DataGrid with Dynamic Columns in a Silverlight Application using MVVM

Basically, she creates a DataGridTemplateColumn and puts ItemsControl inside that displays multiple columns.

How can I throw CHECKED exceptions from inside Java 8 streams?

The only built-in way of handling checked exceptions that can be thrown by a map operation is to encapsulate them within a CompletableFuture. (An Optional is a simpler alternative if you don't need to preserve the exception.) These classes are intended to allow you to represent contingent operations in a functional way.

A couple of non-trivial helper methods are required, but you can arrive at code that's relatively concise, while still making it apparent that your stream's result is contingent on the map operation having completed successfully. Here's what it looks like:

    CompletableFuture<List<Class<?>>> classes =
            Stream.of("java.lang.String", "java.lang.Integer", "java.lang.Double")
                  .map(MonadUtils.applyOrDie(Class::forName))
                  .map(cfc -> cfc.thenApply(Class::getSuperclass))
                  .collect(MonadUtils.cfCollector(ArrayList::new,
                                                  List::add,
                                                  (List<Class<?>> l1, List<Class<?>> l2) -> { l1.addAll(l2); return l1; },
                                                  x -> x));
    classes.thenAccept(System.out::println)
           .exceptionally(t -> { System.out.println("unable to get class: " + t); return null; });

This produces the following output:

[class java.lang.Object, class java.lang.Number, class java.lang.Number]

The applyOrDie method takes a Function that throws an exception, and converts it into a Function that returns an already-completed CompletableFuture -- either completed normally with the original function's result, or completed exceptionally with the thrown exception.

The second map operation illustrates that you've now got a Stream<CompletableFuture<T>> instead of just a Stream<T>. CompletableFuture takes care of only executing this operation if the upstream operation succeeded. The API makes this explict, but relatively painless.

Until you get to the collect phase, that is. This is where we require a pretty significant helper method. We want to "lift" a normal collection operation (in this case, toList()) "inside" the CompletableFuture -- cfCollector() lets us do that using a supplier, accumulator, combiner, and finisher that don't need to know anything at all about CompletableFuture.

The helper methods can be found on GitHub in my MonadUtils class, which is very much still a work in progress.

Read Post Data submitted to ASP.Net Form

if (!string.IsNullOrEmpty(Request.Form["username"])) { ... }

username is the name of the input on the submitting page. The password can be obtained the same way. If its not null or empty, it exists, then log in the user (I don't recall the exact steps for ASP.NET Membership, assuming that's what you're using).

How to find the port for MS SQL Server 2008?

This works for SQL Server 2005 - 2012. Look for event id = 26022 in the error log under applications. That will show the port number of sql server as well as what ip addresses are allowed to access.

.war vs .ear file

Refer: http://www.wellho.net/mouth/754_tar-jar-war-ear-sar-files.html

tar (tape archives) - Format used is file written in serial units of fileName, fileSize, fileData - no compression. can be huge

Jar (java archive) - compression techniques used - generally contains java information like class/java files. But can contain any files and directory structure

war (web application archives) - similar like jar files only have specific directory structure as per JSP/Servlet spec for deployment purposes

ear (enterprise archives) - similar like jar files. have directory structure following J2EE requirements so that it can be deployed on J2EE application servers. - can contain multiple JAR and WAR files

Google Maps API v3: Can I setZoom after fitBounds?

I have come to this page multiple times to get the answer, and while all the existing answers were super helpful, they did not solve my problem exactly.

google.maps.event.addListenerOnce(googleMap, 'zoom_changed', function() {
    var oldZoom = googleMap.getZoom();
    googleMap.setZoom(oldZoom - 1); //Or whatever
});

Basically I found that the 'zoom_changed' event prevented the UI of the map from "skipping" which happened when i waited for the 'idle' event.

Hope this helps somebody!

MSIE and addEventListener Problem in Javascript?

Using <meta http-equiv="X-UA-Compatible" content="IE=9">, IE9+ does support addEventListener by removing the "on" in the event name, like this:

 var btn1 = document.getElementById('btn1');
 btn1.addEventListener('mousedown', function() {
   console.log('mousedown');
 });

How can I wrap text in a label using WPF?

To wrap text in the label control, change the the template of label as follows:

<Style x:Key="ErrorBoxStyle" TargetType="{x:Type Label}">
    <Setter Property="BorderBrush" Value="#FFF08A73"/>
    <Setter Property="BorderThickness" Value="1"/>
    <Setter Property="Foreground" Value="Red"/>
    <Setter Property="Background" Value="#FFFFE3DF"/>
    <Setter Property="FontWeight" Value="Bold"/>
    <Setter Property="Padding" Value="5"/>
    <Setter Property="HorizontalContentAlignment" Value="Left"/>
    <Setter Property="VerticalContentAlignment" Value="Top"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Label}">
                <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true" CornerRadius="5" HorizontalAlignment="Stretch">
                     
                    <TextBlock TextWrapping="Wrap" Text="{TemplateBinding Content}"/>
                </Border>
                    
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

How do you make a div follow as you scroll?

The post is old but I found a perfect CSS for the purpose and I want to share it.

A sticky element toggles between relative and fixed, depending on the scroll position. It is positioned relative until a given offset position is met in the viewport - then it "sticks" in place (like position:fixed).

    div.sticky {
        position: -webkit-sticky; /* Safari */
        position: sticky;
        top: 0;
        background-color: green;
        border: 2px solid #4CAF50;
    }

Source: https://www.w3schools.com/css/css_positioning.asp

How to use matplotlib tight layout with Figure?

Just call fig.tight_layout() as you normally would. (pyplot is just a convenience wrapper. In most cases, you only use it to quickly generate figure and axes objects and then call their methods directly.)

There shouldn't be a difference between the QtAgg backend and the default backend (or if there is, it's a bug).

E.g.

import matplotlib.pyplot as plt

#-- In your case, you'd do something more like:
# from matplotlib.figure import Figure
# fig = Figure()
#-- ...but we want to use it interactive for a quick example, so 
#--    we'll do it this way
fig, axes = plt.subplots(nrows=4, ncols=4)

for i, ax in enumerate(axes.flat, start=1):
    ax.set_title('Test Axes {}'.format(i))
    ax.set_xlabel('X axis')
    ax.set_ylabel('Y axis')

plt.show()

Before Tight Layout

enter image description here

After Tight Layout

import matplotlib.pyplot as plt

fig, axes = plt.subplots(nrows=4, ncols=4)

for i, ax in enumerate(axes.flat, start=1):
    ax.set_title('Test Axes {}'.format(i))
    ax.set_xlabel('X axis')
    ax.set_ylabel('Y axis')

fig.tight_layout()

plt.show()

enter image description here

Bootstrap modal in React.js

I was recently looking for a nice solution to this without adding React-Bootstrap to my project (as Bootstrap 4 is about to be released).

This is my solution: https://jsfiddle.net/16j1se1q/1/

let Modal = React.createClass({
    componentDidMount(){
        $(this.getDOMNode()).modal('show');
        $(this.getDOMNode()).on('hidden.bs.modal', this.props.handleHideModal);
    },
    render(){
        return (
          <div className="modal fade">
            <div className="modal-dialog">
              <div className="modal-content">
                <div className="modal-header">
                  <button type="button" className="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
                  <h4 className="modal-title">Modal title</h4>
                </div>
                <div className="modal-body">
                  <p>One fine body&hellip;</p>
                </div>
                <div className="modal-footer">
                  <button type="button" className="btn btn-default" data-dismiss="modal">Close</button>
                  <button type="button" className="btn btn-primary">Save changes</button>
                </div>
              </div>
            </div>
          </div>
        )
    },
    propTypes:{
        handleHideModal: React.PropTypes.func.isRequired
    }
});



let App = React.createClass({
    getInitialState(){
        return {view: {showModal: false}}
    },
    handleHideModal(){
        this.setState({view: {showModal: false}})
    },
    handleShowModal(){
        this.setState({view: {showModal: true}})
    },
    render(){
    return(
        <div className="row">
            <button className="btn btn-default btn-block" onClick={this.handleShowModal}>Open Modal</button>
            {this.state.view.showModal ? <Modal handleHideModal={this.handleHideModal}/> : null}
        </div>
    );
  }
});

React.render(
   <App />,
    document.getElementById('container')
);

The main idea is to only render the Modal component into the React DOM when it is to be shown (in the App components render function). I keep some 'view' state that indicates whether the Modal is currently shown or not.

The 'componentDidMount' and 'componentWillUnmount' callbacks either hide or show the modal (once it is rendered into the React DOM) via Bootstrap javascript functions.

I think this solution nicely follows the React ethos but suggestions are welcome!

How to resize image automatically on browser width resize but keep same height?

The website you linked doesn't changes the image's width but it actually cuts it off. For that it needs to be set as a background-image.

For more info about background-image look it at http://www.w3schools.com/cssref/pr_background-image.asp

Usage:

#divID {
    background-image:url(image_url);
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

Composer: how can I install another dependency without updating old ones?

To install a new package and only that, you have two options:

  1. Using the require command, just run:

    composer require new/package
    

    Composer will guess the best version constraint to use, install the package, and add it to composer.lock.

    You can also specify an explicit version constraint by running:

    composer require new/package ~2.5
    

–OR–

  1. Using the update command, add the new package manually to composer.json, then run:

    composer update new/package
    

If Composer complains, stating "Your requirements could not be resolved to an installable set of packages.", you can resolve this by passing the flag --with-dependencies. This will whitelist all dependencies of the package you are trying to install/update (but none of your other dependencies).

Regarding the question asker's issues with Laravel and mcrypt: check that it's properly enabled in your CLI php.ini. If php -m doesn't list mcrypt then it's missing.

Important: Don't forget to specify new/package when using composer update! Omitting that argument will cause all dependencies, as well as composer.lock, to be updated.

Maximum size of an Array in Javascript

You could try something like this to test and trim the length:

http://jsfiddle.net/orolo/wJDXL/

_x000D_
_x000D_
var longArray = [1, 2, 3, 4, 5, 6, 7, 8];_x000D_
_x000D_
if (longArray.length >= 6) {_x000D_
  longArray.length = 3;_x000D_
}_x000D_
_x000D_
alert(longArray); //1, 2, 3
_x000D_
_x000D_
_x000D_

What is a Maven artifact?

An artifact is a file, usually a JAR, that gets deployed to a Maven repository.

A Maven build produces one or more artifacts, such as a compiled JAR and a "sources" JAR.

Each artifact has a group ID (usually a reversed domain name, like com.example.foo), an artifact ID (just a name), and a version string. The three together uniquely identify the artifact.

A project's dependencies are specified as artifacts.

How to map to multiple elements with Java 8 streams?

It's an interesting question, because it shows that there are a lot of different approaches to achieve the same result. Below I show three different implementations.


Default methods in Collection Framework: Java 8 added some methods to the collections classes, that are not directly related to the Stream API. Using these methods, you can significantly simplify the implementation of the non-stream implementation:

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    Map<String, DataSet> result = new HashMap<>();
    multiDataPoints.forEach(pt ->
        pt.keyToData.forEach((key, value) ->
            result.computeIfAbsent(
                key, k -> new DataSet(k, new ArrayList<>()))
            .dataPoints.add(new DataPoint(pt.timestamp, value))));
    return result.values();
}

Stream API with flatten and intermediate data structure: The following implementation is almost identical to the solution provided by Stuart Marks. In contrast to his solution, the following implementation uses an anonymous inner class as intermediate data structure.

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    return multiDataPoints.stream()
        .flatMap(mdp -> mdp.keyToData.entrySet().stream().map(e ->
            new Object() {
                String key = e.getKey();
                DataPoint dataPoint = new DataPoint(mdp.timestamp, e.getValue());
            }))
        .collect(
            collectingAndThen(
                groupingBy(t -> t.key, mapping(t -> t.dataPoint, toList())),
                m -> m.entrySet().stream().map(e -> new DataSet(e.getKey(), e.getValue())).collect(toList())));
}

Stream API with map merging: Instead of flattening the original data structures, you can also create a Map for each MultiDataPoint, and then merge all maps into a single map with a reduce operation. The code is a bit simpler than the above solution:

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    return multiDataPoints.stream()
        .map(mdp -> mdp.keyToData.entrySet().stream()
            .collect(toMap(e -> e.getKey(), e -> asList(new DataPoint(mdp.timestamp, e.getValue())))))
        .reduce(new HashMap<>(), mapMerger())
        .entrySet().stream()
        .map(e -> new DataSet(e.getKey(), e.getValue()))
        .collect(toList());
}

You can find an implementation of the map merger within the Collectors class. Unfortunately, it is a bit tricky to access it from the outside. Following is an alternative implementation of the map merger:

<K, V> BinaryOperator<Map<K, List<V>>> mapMerger() {
    return (lhs, rhs) -> {
        Map<K, List<V>> result = new HashMap<>();
        lhs.forEach((key, value) -> result.computeIfAbsent(key, k -> new ArrayList<>()).addAll(value));
        rhs.forEach((key, value) -> result.computeIfAbsent(key, k -> new ArrayList<>()).addAll(value));
        return result;
    };
}

How does the Python's range function work?

When I'm teaching someone programming (just about any language) I introduce for loops with terminology similar to this code example:

for eachItem in someList:
    doSomething(eachItem)

... which, conveniently enough, is syntactically valid Python code.

The Python range() function simply returns or generates a list of integers from some lower bound (zero, by default) up to (but not including) some upper bound, possibly in increments (steps) of some other number (one, by default).

So range(5) returns (or possibly generates) a sequence: 0, 1, 2, 3, 4 (up to but not including the upper bound).

A call to range(2,10) would return: 2, 3, 4, 5, 6, 7, 8, 9

A call to range(2,12,3) would return: 2, 5, 8, 11

Notice that I said, a couple times, that Python's range() function returns or generates a sequence. This is a relatively advanced distinction which usually won't be an issue for a novice. In older versions of Python range() built a list (allocated memory for it and populated with with values) and returned a reference to that list. This could be inefficient for large ranges which might consume quite a bit of memory and for some situations where you might want to iterate over some potentially large range of numbers but were likely to "break" out of the loop early (after finding some particular item in which you were interested, for example).

Python supports more efficient ways of implementing the same semantics (of doing the same thing) through a programming construct called a generator. Instead of allocating and populating the entire list and return it as a static data structure, Python can instantiate an object with the requisite information (upper and lower bounds and step/increment value) ... and return a reference to that.

The (code) object then keeps track of which number it returned most recently and computes the new values until it hits the upper bound (and which point it signals the end of the sequence to the caller using an exception called "StopIteration"). This technique (computing values dynamically rather than all at once, up-front) is referred to as "lazy evaluation."

Other constructs in the language (such as those underlying the for loop) can then work with that object (iterate through it) as though it were a list.

For most cases you don't have to know whether your version of Python is using the old implementation of range() or the newer one based on generators. You can just use it and be happy.

If you're working with ranges of millions of items, or creating thousands of different ranges of thousands each, then you might notice a performance penalty for using range() on an old version of Python. In such cases you could re-think your design and use while loops, or create objects which implement the "lazy evaluation" semantics of a generator, or use the xrange() version of range() if your version of Python includes it, or the range() function from a version of Python that uses the generators implicitly.

Concepts such as generators, and more general forms of lazy evaluation, permeate Python programming as you go beyond the basics. They are usually things you don't have to know for simple programming tasks but which become significant as you try to work with larger data sets or within tighter constraints (time/performance or memory bounds, for example).

[Update: for Python3 (the currently maintained versions of Python) the range() function always returns the dynamic, "lazy evaluation" iterator; the older versions of Python (2.x) which returned a statically allocated list of integers are now officially obsolete (after years of having been deprecated)].

Get String in YYYYMMDD format from JS date object?

You can create yourself function as below

function toString(o, regex) {
    try {
        if (!o) return '';
        if (typeof o.getMonth === 'function' && !!regex) {
            let splitChar = regex.indexOf('/') > -1 ? '/' : regex.indexOf('-') > -1 ? '-' : regex.indexOf('.') > -1 ? '.' : '';
            let dateSeparate = regex.split(splitChar);
            let result = '';
            for (let item of dateSeparate) {
                let val = '';
                switch (item) {
                    case 'd':
                        val = o.getDate();
                        break;
                    case 'dd':
                        val = this.date2Char(o.getDate());
                        break;
                    case 'M':
                        val = o.getMonth() + 1;
                        break;
                    case 'MM':
                        val = this.date2Char(o.getMonth() + 1);
                        break;
                    case 'yyyy':
                        val = o.getFullYear();
                        break;
                    case 'yy':
                        val = this.date2Char(o.getFullYear());
                        break;
                    default:
                        break;
                }
                result += val + splitChar;
            }
            return result.substring(0, result.length - 1);
        } else {
            return o.toString();
        }
    } catch(ex) { return ''; }
}

function concatDateToString(args) {
    if (!args.length) return '';
    let result = '';
    for (let i = 1; i < args.length; i++) {
        result += args[i] + args[0];
    }
    return result.substring(0, result.length - 1);
}

function date2Char(d){
    return this.rightString('0' + d);
}

function rightString(o) {
    return o.substr(o.length - 2);
}

Used:

var a = new Date();
console.log('dd/MM/yyyy: ' + toString(a, 'dd/MM/yyyy'));
console.log('MM/dd/yyyy: ' + toString(a, 'MM/dd/yyyy'));
console.log('dd/MM/yy: ' + toString(a, 'dd/MM/yy'));
console.log('MM/dd/yy: ' + toString(a, 'MM/dd/yy'));

Get File Path (ends with folder)

In the VBA Editor's Tools menu, click References... scroll down to "Microsoft Shell Controls And Automation" and choose it.

Sub FolderSelection()
    Dim MyPath As String
    MyPath = SelectFolder("Select Folder", "")
    If Len(MyPath) Then
        MsgBox MyPath
    Else
        MsgBox "Cancel was pressed"
    End If
End Sub

'Both arguements are optional. The first is the dialog caption and
'the second is is to specify the top-most visible folder in the
'hierarchy. The default is "My Computer."

Function SelectFolder(Optional Title As String, Optional TopFolder _
                         As String) As String
    Dim objShell As New Shell32.Shell
    Dim objFolder As Shell32.Folder

'If you use 16384 instead of 1 on the next line,
'files are also displayed
    Set objFolder = objShell.BrowseForFolder _
                            (0, Title, 1, TopFolder)
    If Not objFolder Is Nothing Then
        SelectFolder = objFolder.Items.Item.Path
    End If
End Function

Source Link.

Rails 4: assets not loading in production

If precompile is set you DO NOT need

config.assets.compile = true

as this is to serve assets live.

Our problem was we only had development secret key base set in config/secrets.yml

development:
    secret_key_base: '83d141eeb181032f4070ae7b1b27d9ff'

Need entry for production environment

Installing Node.js (and npm) on Windows 10

I had the same problem, what helped we was turning of my anti virus protection for like 10 minutes while node installed and it worked like a charm.

Get value of input field inside an iframe

Yes it should be possible, even if the site is from another domain.

For example, in an HTML page on my site I have an iFrame whose contents are sourced from another website. The iFrame content is a single select field.

I need to be able to read the selected value on my site. In other words, I need to use the select list from another domain inside my own application. I do not have control over any server settings.

Initially therefore we might be tempted to do something like this (simplified):

HTML in my site:

<iframe name='select_frame' src='http://www.othersite.com/select.php?initial_name=jim'></iframe>
<input type='button' name='save' value='SAVE'>

HTML contents of iFrame (loaded from select.php on another domain):

<select id='select_name'>
    <option value='john'>John</option>
    <option value='jim' selected>Jim</option>
</select>

jQuery:

$('input:button[name=save]').click(function() {
    var name = $('iframe[name=select_frame]').contents().find('#select_name').val();
});

However, I receive this javascript error when I attempt to read the value:

Blocked a frame with origin "http://www.myownsite.com" from accessing a frame with origin "http://www.othersite.com". Protocols, domains, and ports must match.

To get around this problem, it seems that you can indirectly source the iFrame from a script in your own site, and have that script read the contents from the other site using a method like file_get_contents() or curl etc.

So, create a script (for example: select_local.php in the current directory) on your own site with contents similar to this:

PHP content of select_local.php:

<?php
    $url = "http://www.othersite.com/select.php?" . $_SERVER['QUERY_STRING'];
    $html_select = file_get_contents($url);
    echo $html_select;
?>

Also modify the HTML to call this local (instead of the remote) script:

<iframe name='select_frame' src='select_local.php?initial_name=jim'></iframe>
<input type='button' name='save' value='SAVE'>

Now your browser should think that it is loading the iFrame content from the same domain.

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

There could be any of the following, but all of them lead into DOM not loaded before its accessed by the javascript.

So here is what you have to ensure before actually calling JS code: * Make sure the container has loaded before any javascript is called * Make sure the target URL is loaded in whatever container it has to

I came across the similar issue but on my local when I am trying to have my Javascript run well before onLoad of the main page which causes the error message. I have fixed it by simply waiting for whole page to load and then call the required function.

You could simply do this by adding a timeout function when page has loaded and call your onload event like:

window.onload = new function() { setTimeout(function() { // some onload event }, 10); }

that will ensure what you are trying will execute well after onLoad is trigger.

Best way to increase heap size in catalina.bat file

increase heap size of tomcat for window add this file in apache-tomcat-7.0.42\bin

enter image description here

heap size can be changed based on Requirements.

  set JAVA_OPTS=-Dfile.encoding=UTF-8 -Xms128m -Xmx1024m -XX:PermSize=64m -XX:MaxPermSize=256m

Converting A String To Hexadecimal In Java

new BigInteger(1, myString.getBytes(/*YOUR_CHARSET?*/)).toString(16)

Is it possible to put a ConstraintLayout inside a ScrollView?

Try giving some padding bottom to your constraint layout like below

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/top"
        android:fillViewport="true">

        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingBottom="100dp">
        </android.support.constraint.ConstraintLayout>

    </ScrollView>

Using cut command to remove multiple columns

Sometimes it's easier to think in terms of which fields to exclude.

If the number of fields not being cut (not being retained in the output) is small, it may be easier to use the --complement flag, e.g. to include all fields 1-20 except not 3, 7, and 12 -- do this:

cut -d, --complement -f3,7,12 <inputfile

Rather than

cut -d, -f-2,4-6,8-11,13-

How to remove the left part of a string?

Starting in Python 3.9, you can use removeprefix:

'Path=helloworld'.removeprefix('Path=')
# 'helloworld'

Using PHP to upload file and add the path to MySQL database

First you should use print_r($_FILES) to debug, and see what it contains. :

your uploads.php would look like:

//This is the directory where images will be saved
$target = "pics/";
$target = $target . basename( $_FILES['Filename']['name']);

//This gets all the other information from the form
$Filename=basename( $_FILES['Filename']['name']);
$Description=$_POST['Description'];


//Writes the Filename to the server
if(move_uploaded_file($_FILES['Filename']['tmp_name'], $target)) {
    //Tells you if its all ok
    echo "The file ". basename( $_FILES['Filename']['name']). " has been uploaded, and your information has been added to the directory";
    // Connects to your Database
    mysql_connect("localhost", "root", "") or die(mysql_error()) ;
    mysql_select_db("altabotanikk") or die(mysql_error()) ;

    //Writes the information to the database
    mysql_query("INSERT INTO picture (Filename,Description)
    VALUES ('$Filename', '$Description')") ;
} else {
    //Gives and error if its not
    echo "Sorry, there was a problem uploading your file.";
}



?>

EDIT: Since this is old post, currently it is strongly recommended to use either mysqli or pdo instead mysql_ functions in php

How to use confirm using sweet alert?

swal({
    title: 'Are you sure?',
    text: "You won't be able to revert this!",
    type: 'warning',
    showCancelButton: true,
    confirmButtonColor: '#3085d6',
    cancelButtonColor: '#d33',
    confirmButtonText: 'Confirm!'
}).then(function(){
    alert("The confirm button was clicked");
}).catch(function(reason){
    alert("The alert was dismissed by the user: "+reason);
});

How to convert NSNumber to NSString

or try NSString *string = [NSString stringWithFormat:@"%d", [NSNumber intValue], nil];

How to convert java.lang.Object to ArrayList?

An interesting note: it appears that attempting to cast from an object to a list on the JavaFX Application thread always results in a ClassCastException.

I had the same issue as you, and no answer helped. After playing around for a while, the only thing I could narrow it down to was the thread. Running the code to cast on any other thread other than the UI thread succeeds as expected, and as the other answers in this section suggest.

Thus, be careful that your source isn't running on the JavaFX application thread.

Set element focus in angular way

About this solution, we could just create a directive and attach it to the DOM element that has to get the focus when a given condition is satisfied. By following this approach we avoid coupling controller to DOM element ID's.

Sample code directive:

gbndirectives.directive('focusOnCondition', ['$timeout',
    function ($timeout) {
        var checkDirectivePrerequisites = function (attrs) {
          if (!attrs.focusOnCondition && attrs.focusOnCondition != "") {
                throw "FocusOnCondition missing attribute to evaluate";
          }
        }

        return {            
            restrict: "A",
            link: function (scope, element, attrs, ctrls) {
                checkDirectivePrerequisites(attrs);

                scope.$watch(attrs.focusOnCondition, function (currentValue, lastValue) {
                    if(currentValue == true) {
                        $timeout(function () {                                                
                            element.focus();
                        });
                    }
                });
            }
        };
    }
]);

A possible usage

.controller('Ctrl', function($scope) {
   $scope.myCondition = false;
   // you can just add this to a radiobutton click value
   // or just watch for a value to change...
   $scope.doSomething = function(newMyConditionValue) {
       // do something awesome
       $scope.myCondition = newMyConditionValue;
  };

});

HTML

<input focus-on-condition="myCondition">

Is it possible to assign a base class object to a derived class reference with an explicit typecast?

Another solution is to add extension method like so:

 public static void CopyProperties(this object destinationObject, object sourceObject, bool overwriteAll = true)
        {
            try
            {
                if (sourceObject != null)
                {
                    PropertyInfo[] sourceProps = sourceObject.GetType().GetProperties();
                    List<string> sourcePropNames = sourceProps.Select(p => p.Name).ToList();
                    foreach (PropertyInfo pi in destinationObject.GetType().GetProperties())
                    {
                        if (sourcePropNames.Contains(pi.Name))
                        {
                            PropertyInfo sourceProp = sourceProps.First(srcProp => srcProp.Name == pi.Name);
                            if (sourceProp.PropertyType == pi.PropertyType)
                                if (overwriteAll || pi.GetValue(destinationObject, null) == null)
                                {
                                    pi.SetValue(destinationObject, sourceProp.GetValue(sourceObject, null), null);
                                }
                        }
                    }
                }
            }
            catch (ApplicationException ex)
            {
                throw;
            }
        }

then have a constructor in each derived class that accepts base class:

  public class DerivedClass: BaseClass
    { 
        public DerivedClass(BaseClass baseModel)
        {
            this.CopyProperties(baseModel);
        }
    }

It will also optionally overwrite destination properties if already set (not null) or not.

The difference between bracket [ ] and double bracket [[ ]] for accessing the elements of a list or dataframe

[] extracts a list, [[]] extracts elements within the list

alist <- list(c("a", "b", "c"), c(1,2,3,4), c(8e6, 5.2e9, -9.3e7))

str(alist[[1]])
 chr [1:3] "a" "b" "c"

str(alist[1])
List of 1
 $ : chr [1:3] "a" "b" "c"

str(alist[[1]][1])
 chr "a"

Flattening a shallow list in Python

You almost have it! The way to do nested list comprehensions is to put the for statements in the same order as they would go in regular nested for statements.

Thus, this

for inner_list in outer_list:
    for item in inner_list:
        ...

corresponds to

[... for inner_list in outer_list for item in inner_list]

So you want

[image for menuitem in list_of_menuitems for image in menuitem]

How to redirect docker container logs to a single file?

docker logs -f <yourContainer> &> your.log &

Explanation:

  • -f (i.e.--follow): writes all existing logs and continues (follows) logging everything that comes next.
  • &> redirects both the standard output and standard error.
  • Likely you want to run that method in the background, thus the &.
  • You can separate output and stderr by: > output.log 2> error.log (instead of using &>).

How can I remove all objects but one from the workspace in R?

This takes advantage of ls()'s pattern option, in the case you have a lot of objects with the same pattern that you don't want to keep:

> foo1 <- "junk"; foo2 <- "rubbish"; foo3 <- "trash"; x <- "gold"  
> ls()
[1] "foo1" "foo2" "foo3" "x"   
> # Let's check first what we want to remove
> ls(pattern = "foo")
[1] "foo1" "foo2" "foo3"
> rm(list = ls(pattern = "foo"))
> ls()
[1] "x"

Getting the actual usedrange

This function returns the actual used range to the lower right limit. It returns "Nothing" if the sheet is empty.

'2020-01-26
Function fUsedRange() As Range
Dim lngLastRow As Long
Dim lngLastCol As Long
Dim rngLastCell As Range
    On Error Resume Next
    Set rngLastCell = ActiveSheet.Cells.Find("*", searchorder:=xlByRows, searchdirection:=xlPrevious)
    If rngLastCell Is Nothing Then  'look for data backwards in rows
        Set fUsedRange = Nothing
        Exit Function
    Else
        lngLastRow = rngLastCell.Row
    End If
    Set rngLastCell = ActiveSheet.Cells.Find("*", searchorder:=xlByColumns, searchdirection:=xlPrevious)
    If rngLastCell Is Nothing Then  'look for data backwards in columns
        Set fUsedRange = Nothing
        Exit Function
    Else
        lngLastCol = rngLastCell.Column
    End If
    Set fUsedRange = ActiveSheet.Range(Cells(1, 1), Cells(lngLastRow, lngLastCol))  'set up range
End Function

What is the default value for enum variable?

I think it's quite dangerous to rely on the order of the values in a enum and to assume that the first is always the default. This would be good practice if you are concerned about protecting the default value.

enum E
{
    Foo = 0, Bar, Baz, Quux
}

Otherwise, all it takes is a careless refactor of the order and you've got a completely different default.

Check whether a string matches a regex in JS

Use test() method :

var term = "sample1";
var re = new RegExp("^([a-z0-9]{5,})$");
if (re.test(term)) {
    console.log("Valid");
} else {
    console.log("Invalid");
}

How to change font-size of a tag using inline css?

use this attribute in style

font-size: 11px !important;//your font size

by !important it override your css

Xcode : Adding a project as a build dependency

  1. Select your project in the navigator on left.
  2. Open up the drawer in the middle pane and select your target.
  3. Select Build Phases
  4. Target Dependencies is an option at that point.

How to redirect the output of an application in background to /dev/null

These will also redirect both:

yourcommand  &> /dev/null

yourcommand  >& /dev/null

though the bash manual says the first is preferred.

Android. WebView and loadData

The safest way to load htmlContent in a Web view is to:

  1. use base64 encoding (official recommendation)
  2. specify UFT-8 for html content type, i.e., "text/html; charset=utf-8" instead of "text/html" (personal advice)

"Base64 encoding" is an official recommendation that has been written again (already present in Javadoc) in the latest 01/2019 bug in Chrominium (present in WebView M72 (72.0.3626.76)):

https://bugs.chromium.org/p/chromium/issues/detail?id=929083

Official statement from Chromium team:

"Recommended fix:
Our team recommends you encode data with Base64. We've provided examples for how to do so:

This fix is backwards compatible (it works on earlier WebView versions), and should also be future-proof (you won't hit future compatibility problems with respect to content encoding)."

Code sample:

webView.loadData(
    Base64.encodeToString(
        htmlContent.getBytes(StandardCharsets.UTF_8),
        Base64.DEFAULT), // encode in Base64 encoded 
    "text/html; charset=utf-8", // utf-8 html content (personal recommendation)
    "base64"); // always use Base64 encoded data: NEVER PUT "utf-8" here (using base64 or not): This is wrong! 

Disable Auto Zoom in Input "Text" tag - Safari on iPhone

In Angular you can use directives to prevent zooming on focus on IOS devices. No meta tag to preserve accessibility.

import { Directive, ElementRef, HostListener } from '@angular/core';

const MINIMAL_FONT_SIZE_BEFORE_ZOOMING_IN_PX = 16;

@Directive({ selector: '[noZoomiOS]' })

export class NoZoomiOSDirective {
  constructor(private el: ElementRef) {}

@HostListener('focus')
  onFocus() {
    this.setFontSize('');
  }

@HostListener('mousedown')
  onMouseDown() {
    this.setFontSize(`${MINIMAL_FONT_SIZE_BEFORE_ZOOMING_IN_PX}px`);
  }

private setFontSize(size: string) {
  const { fontSize: currentInputFontSize } = window.getComputedStyle(this.el.nativeElement, null);

  if (MINIMAL_FONT_SIZE_BEFORE_ZOOMING_IN_PX <= +currentInputFontSize.match(/\d+/)) {
      return;
   }

  const iOS = navigator.platform && /iPad|iPhone|iPod/.test(navigator.platform);
  iOS 
     && (this.el.nativeElement.style.fontSize = size);
 }
}

You can use it like this <input noZoomiOS > after you declare it in your *.module.ts

Ignoring SSL certificate in Apache HttpClient 4.3

As an addition to the answer of @mavroprovato, if you want to trust all certificates instead of just self-signed, you'd do (in the style of your code)

builder.loadTrustMaterial(null, new TrustStrategy(){
    public boolean isTrusted(X509Certificate[] chain, String authType)
        throws CertificateException {
        return true;
    }
});

or (direct copy-paste from my own code):

import javax.net.ssl.SSLContext;
import org.apache.http.ssl.TrustStrategy;
import org.apache.http.ssl.SSLContexts;

// ...

        SSLContext sslContext = SSLContexts
                .custom()
                //FIXME to contain real trust store
                .loadTrustMaterial(new TrustStrategy() {
                    @Override
                    public boolean isTrusted(X509Certificate[] chain,
                        String authType) throws CertificateException {
                        return true;
                    }
                })
                .build();

And if you want to skip hostname verification as well, you need to set

    CloseableHttpClient httpclient = HttpClients.custom().setSSLSocketFactory(
            sslsf).setSSLHostnameVerifier( NoopHostnameVerifier.INSTANCE).build();

as well. (ALLOW_ALL_HOSTNAME_VERIFIER is deprecated).

Obligatory warning: you shouldn't really do this, accepting all certificates is a bad thing. However there are some rare use cases where you want to do this.

As a note to code previously given, you'll want to close response even if httpclient.execute() throws an exception

CloseableHttpResponse response = null;
try {
    response = httpclient.execute(httpGet);
    System.out.println(response.getStatusLine());
    HttpEntity entity = response.getEntity();
    EntityUtils.consume(entity);
}
finally {
    if (response != null) {
        response.close();
    }
}

Code above was tested using

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.3</version>
</dependency>

And for the interested, here's my full test set:

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustSelfSignedStrategy;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.ssl.SSLContextBuilder;
import org.apache.http.ssl.TrustStrategy;
import org.apache.http.util.EntityUtils;
import org.junit.Test;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLHandshakeException;
import javax.net.ssl.SSLPeerUnverifiedException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

public class TrustAllCertificatesTest {
    final String expiredCertSite = "https://expired.badssl.com/";
    final String selfSignedCertSite = "https://self-signed.badssl.com/";
    final String wrongHostCertSite = "https://wrong.host.badssl.com/";

    static final TrustStrategy trustSelfSignedStrategy = new TrustSelfSignedStrategy();
    static final TrustStrategy trustAllStrategy = new TrustStrategy(){
        public boolean isTrusted(X509Certificate[] chain, String authType)
                throws CertificateException {
            return true;
        }
    };

    @Test
    public void testSelfSignedOnSelfSignedUsingCode() throws Exception {
        doGet(selfSignedCertSite, trustSelfSignedStrategy);
    }
    @Test(expected = SSLHandshakeException.class)
    public void testExpiredOnSelfSignedUsingCode() throws Exception {
        doGet(expiredCertSite, trustSelfSignedStrategy);
    }
    @Test(expected = SSLPeerUnverifiedException.class)
    public void testWrongHostOnSelfSignedUsingCode() throws Exception {
        doGet(wrongHostCertSite, trustSelfSignedStrategy);
    }

    @Test
    public void testSelfSignedOnTrustAllUsingCode() throws Exception {
        doGet(selfSignedCertSite, trustAllStrategy);
    }
    @Test
    public void testExpiredOnTrustAllUsingCode() throws Exception {
        doGet(expiredCertSite, trustAllStrategy);
    }
    @Test(expected = SSLPeerUnverifiedException.class)
    public void testWrongHostOnTrustAllUsingCode() throws Exception {
        doGet(wrongHostCertSite, trustAllStrategy);
    }

    @Test
    public void testSelfSignedOnAllowAllUsingCode() throws Exception {
        doGet(selfSignedCertSite, trustAllStrategy, NoopHostnameVerifier.INSTANCE);
    }
    @Test
    public void testExpiredOnAllowAllUsingCode() throws Exception {
        doGet(expiredCertSite, trustAllStrategy, NoopHostnameVerifier.INSTANCE);
    }
    @Test
    public void testWrongHostOnAllowAllUsingCode() throws Exception {
        doGet(expiredCertSite, trustAllStrategy, NoopHostnameVerifier.INSTANCE);
    }

    public void doGet(String url, TrustStrategy trustStrategy, HostnameVerifier hostnameVerifier) throws Exception {
        SSLContextBuilder builder = new SSLContextBuilder();
        builder.loadTrustMaterial(trustStrategy);
        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
                builder.build());
        CloseableHttpClient httpclient = HttpClients.custom().setSSLSocketFactory(
                sslsf).setSSLHostnameVerifier(hostnameVerifier).build();

        HttpGet httpGet = new HttpGet(url);
        CloseableHttpResponse response = httpclient.execute(httpGet);
        try {
            System.out.println(response.getStatusLine());
            HttpEntity entity = response.getEntity();
            EntityUtils.consume(entity);
        } finally {
            response.close();
        }
    }
    public void doGet(String url, TrustStrategy trustStrategy) throws Exception {

        SSLContextBuilder builder = new SSLContextBuilder();
        builder.loadTrustMaterial(trustStrategy);
        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
                builder.build());
        CloseableHttpClient httpclient = HttpClients.custom().setSSLSocketFactory(
                sslsf).build();

        HttpGet httpGet = new HttpGet(url);
        CloseableHttpResponse response = httpclient.execute(httpGet);
        try {
            System.out.println(response.getStatusLine());
            HttpEntity entity = response.getEntity();
            EntityUtils.consume(entity);
        } finally {
            response.close();
        }
    }
}

(working test project in github)

Is it possible to have a multi-line comments in R?

No multi-line comments in R as of version 2.12 and unlikely to change. In most environments, you can comment blocks by highlighting and toggle-comment. In emacs, this is 'M-x ;'.

How do I make the first letter of a string uppercase in JavaScript?

CSS only

If the transformation is needed only for displaying on a web page:

p::first-letter {
  text-transform: uppercase;
}
  • Despite being called "::first-letter", it applies to the first character, i.e. in case of string %a, this selector would apply to % and as such a would not be capitalized.
  • In IE9+ or IE5.5+ it's supported in legacy notation with only one colon (:first-letter).

ES2015 one-liner

const capitalizeFirstChar = str => str.charAt(0).toUpperCase() + str.substring(1);

Remarks

  • In the benchmark I performed, there was no significant difference between string.charAt(0) and string[0]. Note however, that string[0] would be undefined for an empty string, so the function would have to be rewritten to use "string && string[0]", which is way too verbose, compared to the alternative.
  • string.substring(1) is faster than string.slice(1).

Benchmark between substring() and slice()

The difference is rather minuscule nowadays (run the test yourself):

  • 21,580,613.15 ops/s ±1.6% for substring(),
  • 21,096,394.34 ops/s ±1.8% (2.24% slower) for slice().

Solutions' comparison

Have a fixed position div that needs to scroll if content overflows

The solutions here didn't work for me as I'm styling react components.

What worked though for the sidebar was

.sidebar{
position: sticky;
top: 0;
}

Hope this helps someone.

How can you represent inheritance in a database?

Alternatively, consider using a document databases (such as MongoDB) which natively support rich data structures and nesting.

Convert string to hex-string in C#

According to this snippet here, this approach should be good for long strings:

private string StringToHex(string hexstring)
{
    StringBuilder sb = new StringBuilder();
    foreach (char t in hexstring)
    { 
        //Note: X for upper, x for lower case letters
        sb.Append(Convert.ToInt32(t).ToString("x")); 
    }
    return sb.ToString();
}

usage:

string result = StringToHex("Hello world"); //returns "48656c6c6f20776f726c64"

Another approach in one line

string input = "Hello world";
string result = String.Concat(input.Select(x => ((int)x).ToString("x")));

Checking for empty or null JToken in a JObject

As of C# 7 you could also use this:

if (clientsParsed["objects"] is JArray clients) 
{
    foreach (JObject item in clients.Children())
    {
        if (item["thisParameter"] as JToken itemToken) 
        {
            command.Parameters["@MyParameter"].Value = JTokenToSql(itemToken);
        }
    }
}

The is Operator checks the Type and if its corrects the Value is inside the clients variable.

How do you handle a form change in jQuery?

Looking at the updated question try something like

$('input, textarea, select').each(function(){
    $(this).data("val", $(this).val());
});
$('#button').click(function() {
    $('input, textarea, select').each(function(){
        if($(this).data("val")!==$(this).val()) alert("Things Changed");
    });
});

For the original question use something like

$('input').change(function() {
    alert("Things have changed!");
});

codeigniter, result() vs. result_array()

result() is recursive in that it returns an std class object where as result_array() just returns a pure array, so result_array() would be choice regarding performance. There is very little difference in speed though.

How can I test that a variable is more than eight characters in PowerShell?

You can also use -match against a Regular expression. Ex:

if ($dbUserName -match ".{8}" )
{
    Write-Output " Please enter more than 8 characters "
    $dbUserName=read-host " Re-enter database user name"
}

Also if you're like me and like your curly braces to be in the same horizontal position for your code blocks, you can put that on a new line, since it's expecting a code block it will look on next line. In some commands where the first curly brace has to be in-line with your command, you can use a grave accent marker (`) to tell powershell to treat the next line as a continuation.

Update elements in a JSONObject

public static JSONObject updateJson(JSONObject obj, String keyString, String newValue) throws Exception {
            JSONObject json = new JSONObject();
            // get the keys of json object
            Iterator iterator = obj.keys();
            String key = null;
            while (iterator.hasNext()) {
                key = (String) iterator.next();
                // if the key is a string, then update the value
                if ((obj.optJSONArray(key) == null) && (obj.optJSONObject(key) == null)) {
                    if ((key.equals(keyString))) {
                        // put new value
                        obj.put(key, newValue);
                        return obj;
                    }
                }

                // if it's jsonobject
                if (obj.optJSONObject(key) != null) {
                    updateJson(obj.getJSONObject(key), keyString, newValue);
                }

                // if it's jsonarray
                if (obj.optJSONArray(key) != null) {
                    JSONArray jArray = obj.getJSONArray(key);
                    for (int i = 0; i < jArray.length(); i++) {
                        updateJson(jArray.getJSONObject(i), keyString, newValue);
                    }
                }
            }
            return obj;
        }

Unsupported operand type(s) for +: 'int' and 'str'

try,

str_list = " ".join([str(ele) for ele in numlist])

this statement will give you each element of your list in string format

print("The list now looks like [{0}]".format(str_list))

and,

change print(numlist.pop(2)+" has been removed") to

print("{0} has been removed".format(numlist.pop(2)))

as well.

Django CharField vs TextField

CharField has max_length of 255 characters while TextField can hold more than 255 characters. Use TextField when you have a large string as input. It is good to know that when the max_length parameter is passed into a TextField it passes the length validation to the TextArea widget.

Bubble Sort Homework

I consider adding my solution because ever solution here is having

  1. greater time
  2. greater space complexity
  3. or doing too much operations

then is should be

So, here is my solution:


def countInversions(arr):
    count = 0
    n = len(arr)
    for i in range(n):
        _count = count
        for j in range(0, n - i - 1):
            if arr[j] > arr[j + 1]:
                count += 1
                arr[j], arr[j + 1] = arr[j + 1], arr[j]
        if _count == count:
            break
    return count

How can you customize the numbers in an ordered list?

This is the solution I have working in Firefox 3, Opera and Google Chrome. The list still displays in IE7 (but without the close bracket and left align numbers):

_x000D_
_x000D_
ol {_x000D_
  counter-reset: item;_x000D_
  margin-left: 0;_x000D_
  padding-left: 0;_x000D_
}_x000D_
li {_x000D_
  display: block;_x000D_
  margin-bottom: .5em;_x000D_
  margin-left: 2em;_x000D_
}_x000D_
li::before {_x000D_
  display: inline-block;_x000D_
  content: counter(item) ") ";_x000D_
  counter-increment: item;_x000D_
  width: 2em;_x000D_
  margin-left: -2em;_x000D_
}
_x000D_
<ol>_x000D_
  <li>One</li>_x000D_
  <li>Two</li>_x000D_
  <li>Three</li>_x000D_
  <li>Four</li>_x000D_
  <li>Five</li>_x000D_
  <li>Six</li>_x000D_
  <li>Seven</li>_x000D_
  <li>Eight</li>_x000D_
  <li>Nine<br>Items</li>_x000D_
  <li>Ten<br>Items</li>_x000D_
</ol>
_x000D_
_x000D_
_x000D_

EDIT: Included multiple line fix by strager

Also is there a CSS solution to change from numbers to alphabetic/roman lists instead of using the type attribute on the ol element.

Refer to list-style-type CSS property. Or when using counters the second argument accepts a list-style-type value. For example the following will use upper roman:

li::before {
  content: counter(item, upper-roman) ") ";
  counter-increment: item;
/* ... */

Unable to load script.Make sure you are either running a Metro server or that your bundle 'index.android.bundle' is packaged correctly for release

In Some Cases You Might Want To Close the port Of React-native bundler and Rerun the App With the same process

1.sudo kill -9 $(sudo lsof -t -i:9001)

2.npm start inside the project

3. react-native run-android

JPA Hibernate Persistence exception [PersistenceUnit: default] Unable to build Hibernate SessionFactory

I found some issue about that kind of error

  1. Database username or password not match in the mysql or other other database. Please set application.properties like this

  

# =============================== # = DATA SOURCE # =============================== # Set here configurations for the database connection # Connection url for the database please let me know "[email protected]" spring.datasource.url = jdbc:mysql://localhost:3306/bookstoreapiabc # Username and secret spring.datasource.username = root spring.datasource.password = # Keep the connection alive if idle for a long time (needed in production) spring.datasource.testWhileIdle = true spring.datasource.validationQuery = SELECT 1 # =============================== # = JPA / HIBERNATE # =============================== # Use spring.jpa.properties.* for Hibernate native properties (the prefix is # stripped before adding them to the entity manager). # Show or not log for each sql query spring.jpa.show-sql = true # Hibernate ddl auto (create, create-drop, update): with "update" the database # schema will be automatically updated accordingly to java entities found in # the project spring.jpa.hibernate.ddl-auto = update # Allows Hibernate to generate SQL optimized for a particular DBMS spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect

Issue no 2.

Your local server has two database server and those database server conflict. this conflict like this mysql server & xampp or lampp or wamp server. Please one of the database like mysql server because xampp or lampp server automatically install mysql server on this machine

tomcat - CATALINA_BASE and CATALINA_HOME variables

CATALINA_HOME vs CATALINA_BASE

If you're running multiple instances, then you need both variables, otherwise only CATALINA_HOME.

In other words: CATALINA_HOME is required and CATALINA_BASE is optional.

CATALINA_HOME represents the root of your Tomcat installation.

Optionally, Tomcat may be configured for multiple instances by defining $CATALINA_BASE for each instance. If multiple instances are not configured, $CATALINA_BASE is the same as $CATALINA_HOME.

See: Apache Tomcat 7 - Introduction

Running with separate CATALINA_HOME and CATALINA_BASE is documented in RUNNING.txt which say:

The CATALINA_HOME and CATALINA_BASE environment variables are used to specify the location of Apache Tomcat and the location of its active configuration, respectively.

You cannot configure CATALINA_HOME and CATALINA_BASE variables in the setenv script, because they are used to find that file.

For example:

(4.1) Tomcat can be started by executing one of the following commands:

  %CATALINA_HOME%\bin\startup.bat         (Windows)

  $CATALINA_HOME/bin/startup.sh           (Unix)

or

  %CATALINA_HOME%\bin\catalina.bat start  (Windows)

  $CATALINA_HOME/bin/catalina.sh start    (Unix)

Multiple Tomcat Instances

In many circumstances, it is desirable to have a single copy of a Tomcat binary distribution shared among multiple users on the same server. To make this possible, you can set the CATALINA_BASE environment variable to the directory that contains the files for your 'personal' Tomcat instance.

When running with a separate CATALINA_HOME and CATALINA_BASE, the files and directories are split as following:

In CATALINA_BASE:

  • bin - Only: setenv.sh (*nix) or setenv.bat (Windows), tomcat-juli.jar
  • conf - Server configuration files (including server.xml)
  • lib - Libraries and classes, as explained below
  • logs - Log and output files
  • webapps - Automatically loaded web applications
  • work - Temporary working directories for web applications
  • temp - Directory used by the JVM for temporary files>

In CATALINA_HOME:

  • bin - Startup and shutdown scripts
  • lib - Libraries and classes, as explained below
  • endorsed - Libraries that override standard "Endorsed Standards". By default it's absent.

How to check

The easiest way to check what's your CATALINA_BASE and CATALINA_HOME is by running startup.sh, for example:

$ /usr/share/tomcat7/bin/startup.sh
Using CATALINA_BASE:   /usr/share/tomcat7
Using CATALINA_HOME:   /usr/share/tomcat7

You may also check where the Tomcat files are installed, by dpkg tool as below (Debian/Ubuntu):

dpkg -L tomcat7-common

How to get exact browser name and version?

  • There is a conflict between (Safari) and (Opera) and (Chrome) !!!

  • The above codes couldn't work properly

This is my code, and it works very well without any conflict:

function ExactBrowserName()
{

$ExactBrowserNameUA=$_SERVER['HTTP_USER_AGENT'];

if (strpos(strtolower($ExactBrowserNameUA), "safari/") and strpos(strtolower($ExactBrowserNameUA), "opr/")) {
    // OPERA
    $ExactBrowserNameBR="Opera";
} elseIf (strpos(strtolower($ExactBrowserNameUA), "safari/") and strpos(strtolower($ExactBrowserNameUA), "chrome/")) {
    // CHROME
    $ExactBrowserNameBR="Chrome";
} elseIf (strpos(strtolower($ExactBrowserNameUA), "msie")) {
    // INTERNET EXPLORER
    $ExactBrowserNameBR="Internet Explorer";
} elseIf (strpos(strtolower($ExactBrowserNameUA), "firefox/")) {
    // FIREFOX
    $ExactBrowserNameBR="Firefox";
} elseIf (strpos(strtolower($ExactBrowserNameUA), "safari/") and strpos(strtolower($ExactBrowserNameUA), "opr/")==false and strpos(strtolower($ExactBrowserNameUA), "chrome/")==false) {
    // SAFARI
    $ExactBrowserNameBR="Safari";
} else {
    // OUT OF DATA
    $ExactBrowserNameBR="OUT OF DATA";
};

return $ExactBrowserNameBR;
}

How does numpy.newaxis work and when to use it?

What is np.newaxis?

The np.newaxis is just an alias for the Python constant None, which means that wherever you use np.newaxis you could also use None:

>>> np.newaxis is None
True

It's just more descriptive if you read code that uses np.newaxis instead of None.

How to use np.newaxis?

The np.newaxis is generally used with slicing. It indicates that you want to add an additional dimension to the array. The position of the np.newaxis represents where I want to add dimensions.

>>> import numpy as np
>>> a = np.arange(10)
>>> a
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> a.shape
(10,)

In the first example I use all elements from the first dimension and add a second dimension:

>>> a[:, np.newaxis]
array([[0],
       [1],
       [2],
       [3],
       [4],
       [5],
       [6],
       [7],
       [8],
       [9]])
>>> a[:, np.newaxis].shape
(10, 1)

The second example adds a dimension as first dimension and then uses all elements from the first dimension of the original array as elements in the second dimension of the result array:

>>> a[np.newaxis, :]  # The output has 2 [] pairs!
array([[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]])
>>> a[np.newaxis, :].shape
(1, 10)

Similarly you can use multiple np.newaxis to add multiple dimensions:

>>> a[np.newaxis, :, np.newaxis]  # note the 3 [] pairs in the output
array([[[0],
        [1],
        [2],
        [3],
        [4],
        [5],
        [6],
        [7],
        [8],
        [9]]])
>>> a[np.newaxis, :, np.newaxis].shape
(1, 10, 1)

Are there alternatives to np.newaxis?

There is another very similar functionality in NumPy: np.expand_dims, which can also be used to insert one dimension:

>>> np.expand_dims(a, 1)  # like a[:, np.newaxis]
>>> np.expand_dims(a, 0)  # like a[np.newaxis, :]

But given that it just inserts 1s in the shape you could also reshape the array to add these dimensions:

>>> a.reshape(a.shape + (1,))  # like a[:, np.newaxis]
>>> a.reshape((1,) + a.shape)  # like a[np.newaxis, :]

Most of the times np.newaxis is the easiest way to add dimensions, but it's good to know the alternatives.

When to use np.newaxis?

In several contexts is adding dimensions useful:

  • If the data should have a specified number of dimensions. For example if you want to use matplotlib.pyplot.imshow to display a 1D array.

  • If you want NumPy to broadcast arrays. By adding a dimension you could for example get the difference between all elements of one array: a - a[:, np.newaxis]. This works because NumPy operations broadcast starting with the last dimension 1.

  • To add a necessary dimension so that NumPy can broadcast arrays. This works because each length-1 dimension is simply broadcast to the length of the corresponding1 dimension of the other array.


1 If you want to read more about the broadcasting rules the NumPy documentation on that subject is very good. It also includes an example with np.newaxis:

>>> a = np.array([0.0, 10.0, 20.0, 30.0])
>>> b = np.array([1.0, 2.0, 3.0])
>>> a[:, np.newaxis] + b
array([[  1.,   2.,   3.],
       [ 11.,  12.,  13.],
       [ 21.,  22.,  23.],
       [ 31.,  32.,  33.]])

C# int to enum conversion

I'm pretty sure you can do explicit casting here.

foo f = (foo)value;

So long as you say the enum inherits(?) from int, which you have.

enum foo : int

EDIT Yes it turns out that by default, an enums underlying type is int. You can however use any integral type except char.

You can also cast from a value that's not in the enum, producing an invalid enum. I suspect this works by just changing the type of the reference and not actually changing the value in memory.

enum (C# Reference)
Enumeration Types (C# Programming Guide)

How to find the socket connection state in C?

On Windows you can query the precise state of any port on any network-adapter using: GetExtendedTcpTable

You can filter it to only those related to your process, etc and do as you wish periodically monitoring as needed. This is "an alternative" approach.

You could also duplicate the socket handle and set up an IOCP/Overlapped i/o wait on the socket and monitor it that way as well.

Can I give the col-md-1.5 in bootstrap?

Bootstrap 4 uses flex-box and you can create your own column definitions

This is close to a 1.5, tweak to your own needs.

.col-1-5 {
    flex: 0 0 12.3%;
    max-width: 12.3%;
    position: relative;
    width: 100%;
    padding-right: 15px;
    padding-left: 15px;
}

jQuery get mouse position within an element

This solution supports all major browsers including IE. It also takes care of scrolling. First, it retrieves the position of the element relative to the page efficiently, and without using a recursive function. Then it gets the x and y of the mouse click relative to the page and does the subtraction to get the answer which is the position relative to the element (the element can be an image or div for example):

function getXY(evt) {
    var element = document.getElementById('elementId');  //replace elementId with your element's Id.
    var rect = element.getBoundingClientRect();
    var scrollTop = document.documentElement.scrollTop?
                    document.documentElement.scrollTop:document.body.scrollTop;
    var scrollLeft = document.documentElement.scrollLeft?                   
                    document.documentElement.scrollLeft:document.body.scrollLeft;
    var elementLeft = rect.left+scrollLeft;  
    var elementTop = rect.top+scrollTop;

        if (document.all){ //detects using IE   
            x = event.clientX+scrollLeft-elementLeft; //event not evt because of IE
            y = event.clientY+scrollTop-elementTop;
        }
        else{
            x = evt.pageX-elementLeft;
            y = evt.pageY-elementTop;
    }

Uncaught SyntaxError: Unexpected token :

My mistake was forgetting single/double quotation around url in javascript:

so wrong code was:

window.location = https://google.com;

and correct code:

window.location = "https://google.com";

Rename multiple files in cmd

I found the following in a small comment in Supperuser.com:

@JacksOnF1re - New information/technique added to my answer. You can actually delete your Copy of prefix using an obscure forward slash technique: ren "Copy of .txt" "////////"

Of How does the Windows RENAME command interpret wildcards? See in this thread, the answer of dbenham.

My problem was slightly different, I wanted to add a Prefix to the file and remove from the beginning what I don't need. In my case I had several hundred of enumerated files such as:

SKMBT_C36019101512510_001.jpg
SKMBT_C36019101512510_002.jpg
SKMBT_C36019101512510_003.jpg
SKMBT_C36019101512510_004.jpg
:
:

Now I wanted to respectively rename them all to (Album 07 picture #):

A07_P001.jpg
A07_P002.jpg
A07_P003.jpg
A07_P004.jpg
:
:

I did it with a single command line and it worked like charm:

ren "SKMBT_C36019101512510_*.*" "/////////////////A06_P*.*"

Note:

  1. Quoting (") the "<Name Scheme>" is not an option, it does not work otherwise, in our example: "SKMBT_C36019101512510_*.*" and "/////////////////A06_P*.*" were quoted.
  2. I had to exactly count the number of characters I want to remove and leave space for my new characters: The A06_P actually replaced 2510_ and the SKMBT_C3601910151 was removed, by using exactly the number of slashes ///////////////// (17 characters).
  3. I recommend copying your files (making a backup), before applying the above.

Get img thumbnails from Vimeo?

In javascript (uses jQuery):

function vimeoLoadingThumb(id){    
    var url = "http://vimeo.com/api/v2/video/" + id + ".json?callback=showThumb";

    var id_img = "#vimeo-" + id;

    var script = document.createElement( 'script' );
    script.src = url;

    $(id_img).before(script);
}


function showThumb(data){
    var id_img = "#vimeo-" + data[0].id;
    $(id_img).attr('src',data[0].thumbnail_medium);
}

To display it :

<img id="vimeo-{{ video.id_video }}" src="" alt="{{ video.title }}" />
<script type="text/javascript">
  vimeoLoadingThumb({{ video.id_video }});
</script>

Converting URL to String and back again

There is a nicer way of getting the string version of the path from the NSURL in Swift:

let path:String = url.path

Asp.Net WebApi2 Enable CORS not working with AspNet.WebApi.Cors 5.2.3

I just added custom headers to the Web.config and it worked like a charm.

On configuration - system.webServer:

<httpProtocol>
  <customHeaders>
    <add name="Access-Control-Allow-Origin" value="*" />
    <add name="Access-Control-Allow-Headers" value="Content-Type" />
  </customHeaders>
</httpProtocol>

I have the front end app and the backend on the same solution. For this to work, I need to set the web services project (Backend) as the default for this to work.

I was using ReST, haven't tried with anything else.

Best way to extract a subvector from a vector?

Posting this late just for others..I bet the first coder is done by now. For simple datatypes no copy is needed, just revert to good old C code methods.

std::vector <int>   myVec;
int *p;
// Add some data here and set start, then
p=myVec.data()+start;

Then pass the pointer p and a len to anything needing a subvector.

notelen must be!! len < myVec.size()-start

String's Maximum length in Java - calling length() method

Considering the String class' length method returns an int, the maximum length that would be returned by the method would be Integer.MAX_VALUE, which is 2^31 - 1 (or approximately 2 billion.)

In terms of lengths and indexing of arrays, (such as char[], which is probably the way the internal data representation is implemented for Strings), Chapter 10: Arrays of The Java Language Specification, Java SE 7 Edition says the following:

The variables contained in an array have no names; instead they are referenced by array access expressions that use nonnegative integer index values. These variables are called the components of the array. If an array has n components, we say n is the length of the array; the components of the array are referenced using integer indices from 0 to n - 1, inclusive.

Furthermore, the indexing must be by int values, as mentioned in Section 10.4:

Arrays must be indexed by int values;

Therefore, it appears that the limit is indeed 2^31 - 1, as that is the maximum value for a nonnegative int value.

However, there probably are going to be other limitations, such as the maximum allocatable size for an array.

How to terminate a python subprocess launched with shell=True

Send the signal to all the processes in group

    self.proc = Popen(commands, 
            stdout=PIPE, 
            stderr=STDOUT, 
            universal_newlines=True, 
            preexec_fn=os.setsid)

    os.killpg(os.getpgid(self.proc.pid), signal.SIGHUP)
    os.killpg(os.getpgid(self.proc.pid), signal.SIGTERM)

Update a local branch with the changes from a tracked remote branch

You have set the upstream of that branch

(see:

git branch -f --track my_local_branch origin/my_remote_branch
# OR (if my_local_branch is currently checked out):
$ git branch --set-upstream-to my_local_branch origin/my_remote_branch

(git branch -f --track won't work if the branch is checked out: use the second command git branch --set-upstream-to instead, or you would get "fatal: Cannot force update the current branch.")

That means your branch is already configured with:

branch.my_local_branch.remote origin
branch.my_local_branch.merge my_remote_branch

Git already has all the necessary information.
In that case:

# if you weren't already on my_local_branch branch:
git checkout my_local_branch 
# then:
git pull

is enough.


If you hadn't establish that upstream branch relationship when it came to push your 'my_local_branch', then a simple git push -u origin my_local_branch:my_remote_branch would have been enough to push and set the upstream branch.
After that, for the subsequent pulls/pushes, git pull or git push would, again, have been enough.

Java String.split() Regex

    String str = "a + b - c * d / e < f > g >= h <= i == j";
    String reg = "\\s*[a-zA-Z]+";

    String[] res = str.split(reg);
    for (String out : res) {
        if (!"".equals(out)) {
            System.out.print(out);
        }
    }

Output : + - * / < > >= <= ==

How to write "Html.BeginForm" in Razor

The following code works fine:

@using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
{
    @Html.ValidationSummary(true)
    <fieldset>
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />
    </fieldset>
}

and generates as expected:

<form action="/Upload/Upload" enctype="multipart/form-data" method="post">    
    <fieldset>
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />
    </fieldset>
</form>

On the other hand if you are writing this code inside the context of other server side construct such as an if or foreach you should remove the @ before the using. For example:

@if (SomeCondition)
{
    using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
    {
        @Html.ValidationSummary(true)
        <fieldset>
            Select a file <input type="file" name="file" />
            <input type="submit" value="Upload" />
        </fieldset>
    }
}

As far as your server side code is concerned, here's how to proceed:

[HttpPost]
public ActionResult Upload(HttpPostedFileBase file) 
{
    if (file != null && file.ContentLength > 0) 
    {
        var fileName = Path.GetFileName(file.FileName);
        var path = Path.Combine(Server.MapPath("~/content/pics"), fileName);
        file.SaveAs(path);
    }
    return RedirectToAction("Upload");
}

print variable and a string in python

Assuming you use Python 2.7 (not 3):

print "I have", card.price (as mentioned above).

print "I have %s" % card.price (using string formatting)

print " ".join(map(str, ["I have", card.price])) (by joining lists)

There are a lot of ways to do the same, actually. I would prefer the second one.

Convert number to month name in PHP

This for all needs of date-time converting

 <?php
 $newDate = new DateTime('2019-03-27 03:41:41');
 echo $newDate->format('M d, Y, h:i:s a');
 ?>

PDF Blob - Pop up window not showing content

If you set { responseType: 'blob' }, no need to create Blob on your own. You can simply create url based with response content:

$http({
    url: "...",
    method: "POST",
    responseType: "blob"
}).then(function(response) {
    var fileURL = URL.createObjectURL(response.data);
    window.open(fileURL);
});

pandas groupby sort descending order

This kind of operation is covered under hierarchical indexing. Check out the examples here

When you groupby, you're making new indices. If you also pass a list through .agg(). you'll get multiple columns. I was trying to figure this out and found this thread via google.

It turns out if you pass a tuple corresponding to the exact column you want sorted on.

Try this:

# generate toy data 
ex = pd.DataFrame(np.random.randint(1,10,size=(100,3)), columns=['features', 'AUC', 'recall'])

# pass a tuple corresponding to which specific col you want sorted. In this case, 'mean' or 'AUC' alone are not unique. 
ex.groupby('features').agg(['mean','std']).sort_values(('AUC', 'mean'))

This will output a df sorted by the AUC-mean column only.

Div Height in Percentage

It doesn't take the 50% of the whole page is because the "whole page" is only how tall your contents are. Change the enclosing html and body to 100% height and it will work.

html, body{
    height: 100%;
}
div{
    height: 50%;
}

http://jsfiddle.net/DerekL/5YukJ/1/

enter image description here

^ Your document is only 20px high. 50% of 20px is 10px, and it is not what you expected.

enter image description here

^ Now if you change the height of the document to the height of the whole page (150px), 50% of 150px is 75px, then it will work.

What is a segmentation fault?

A segmentation fault or access violation occurs when a program attempts to access a memory location that is not exist, or attempts to access a memory location in a way that is not allowed.

 /* "Array out of bounds" error 
   valid indices for array foo
   are 0, 1, ... 999 */
   int foo[1000];
   for (int i = 0; i <= 1000 ; i++) 
   foo[i] = i;

Here i[1000] not exist, so segfault occurs.

Causes of segmentation fault:

it arise primarily due to errors in use of pointers for virtual memory addressing, particularly illegal access.

De-referencing NULL pointers – this is special-cased by memory management hardware.

Attempting to access a nonexistent memory address (outside process’s address space).

Attempting to access memory the program does not have rights to (such as kernel structures in process context).

Attempting to write read-only memory (such as code segment).

Android replace the current fragment with another fragment

Use android.support.v4.app for FragmentManager & FragmentTransaction in your code, it has worked for me.

DetailsFragment detailsFragment = new DetailsFragment();
android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
android.support.v4.app.FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.details,detailsFragment);
fragmentTransaction.commit();

jQuery attr() change img src

  1. Function imageMorph will create a new img element therefore the id is removed. Changed to

    $("#wrapper > img")

  2. You should use live() function for click event if you want you rocket lanch again.

Updated demo: http://jsfiddle.net/ynhat/QQRsW/4/

How to find the process id of a running Java process on Windows? And how to kill the process alone?

  1. Open Git Bash
  2. Type ps -ef | grep java
  3. Find the pid of running jdk
  4. kill -9 [pid]

Using the last-child selector

The :last-child pseudoclass still cannot be reliably used across browsers. In particular, Internet Explorer versions < 9, and Safari < 3.2 definitely don't support it, although Internet Explorer 7 and Safari 3.2 do support :first-child, curiously.

Your best bet is to explicitly add a last-child (or similar) class to that item, and apply li.last-child instead.

Convert Java Date to UTC String

tl;dr

You asked:

I was looking for a one-liner like:

Ask and ye shall receive. Convert from terrible legacy class Date to its modern replacement, Instant.

myJavaUtilDate.toInstant().toString()

2020-05-05T19:46:12.912Z

java.time

In Java 8 and later we have the new java.time package built in (Tutorial). Inspired by Joda-Time, defined by JSR 310, and extended by the ThreeTen-Extra project.

The best solution is to sort your date-time objects rather than strings. But if you must work in strings, read on.

An Instant represents a moment on the timeline, basically in UTC (see class doc for precise details). The toString implementation uses the DateTimeFormatter.ISO_INSTANT format by default. This format includes zero, three, six or nine digits digits as needed to display fraction of a second up to nanosecond precision.

String output = Instant.now().toString(); // Example: '2015-12-03T10:15:30.120Z'

If you must interoperate with the old Date class, convert to/from java.time via new methods added to the old classes. Example: Date::toInstant.

myJavaUtilDate.toInstant().toString()

You may want to use an alternate formatter if you need a consistent number of digits in the fractional second or if you need no fractional second.

Another route if you want to truncate fractions of a second is to use ZonedDateTime instead of Instant, calling its method to change the fraction to zero.

Note that we must specify a time zone for ZonedDateTime (thus the name). In our case that means UTC. The subclass of ZoneID, ZoneOffset, holds a convenient constant for UTC. If we omit the time zone, the JVM’s current default time zone is implicitly applied.

String output = ZonedDateTime.now( ZoneOffset.UTC ).withNano( 0 ).toString();  // Example: 2015-08-27T19:28:58Z

Table of date-time types in Java, both modern and legacy


About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.

Where to obtain the java.time classes?


Joda-Time

UPDATE: The Joda -Time project is now in maintenance mode, with the team advising migration to the java.time classes.

I was looking for a one-liner

Easy if using the Joda-Time 2.3 library. ISO 8601 is the default formatting.

Time Zone

In the code example below, note that I am specifying a time zone rather than depending on the default time zone. In this case, I'm specifying UTC per your question. The Z on the end, spoken as "Zulu", means no time zone offset from UTC.

Example Code

// import org.joda.time.*;

String output = new DateTime( DateTimeZone.UTC );

Output…

2013-12-12T18:29:50.588Z

What does the regex \S mean in JavaScript?

\s matches whitespace (spaces, tabs and new lines). \S is negated \s.

Best way to center a <div> on a page vertically and horizontally?

Sorry for late reply best way is

  div {
      position: fixed;
      top: 50%;
      left: 50%;
      margin-top: -50px;
      margin-left: -100px;
    }

margin-top and margin-left should be according to your div box size

Display two fields side by side in a Bootstrap Form

@KyleMit's answer on Bootstrap 4 has changed a little

<div class="input-group">
    <input type="text" class="form-control">
    <div class="input-group-prepend">
        <span class="input-group-text">-</span>
    </div>
    <input type="text" class="form-control">
</div>

Android WebView not loading URL

Add Permission Internet permission in manifest.

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

This code it working

  public class WebActivity extends Activity {
  WebView wv;

 String url="http://www.teluguoneradio.com/rssHostDescr.php?hostId=147";

 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_web);
    wv=(WebView)findViewById(R.id.webUrl_WEB);



WebSettings webSettings = wv.getSettings();
    wv.getSettings().setLoadWithOverviewMode(true);
    wv.getSettings().setUseWideViewPort(true);
    wv.getSettings().setBuiltInZoomControls(true);
    wv.getSettings().setPluginState(PluginState.ON);


    wv.setWebViewClient(new myWebClient());

    wv.loadUrl(url);
}




public class myWebClient extends WebViewClient {
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        // TODO Auto-generated method stub
        super.onPageStarted(view, url, favicon);
    }

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        // TODO Auto-generated method stub

        view.loadUrl(url);
        return true;

    }
}

New lines (\r\n) are not working in email body

You need to use <br> instead of \r\n . For this you can use built in function call nl2br So your code should be like this

 $message = nl2br("CCCC\r\nCCCC CCCC \r CCC \n CCC \r\n CCC \n\r CCCC");

What is the lifetime of a static variable in a C++ function?

The lifetime of function static variables begins the first time[0] the program flow encounters the declaration and it ends at program termination. This means that the run-time must perform some book keeping in order to destruct it only if it was actually constructed.

Additionally, since the standard says that the destructors of static objects must run in the reverse order of the completion of their construction[1], and the order of construction may depend on the specific program run, the order of construction must be taken into account.

Example

struct emitter {
    string str;
    emitter(const string& s) : str(s) { cout << "Created " << str << endl; }
    ~emitter() { cout << "Destroyed " << str << endl; }
};

void foo(bool skip_first) 
{
    if (!skip_first)
        static emitter a("in if");
    static emitter b("in foo");
}

int main(int argc, char*[])
{
    foo(argc != 2);
    if (argc == 3)
        foo(false);
}

Output:

C:>sample.exe
Created in foo
Destroyed in foo

C:>sample.exe 1
Created in if
Created in foo
Destroyed in foo
Destroyed in if

C:>sample.exe 1 2
Created in foo
Created in if
Destroyed in if
Destroyed in foo

[0] Since C++98[2] has no reference to multiple threads how this will be behave in a multi-threaded environment is unspecified, and can be problematic as Roddy mentions.

[1] C++98 section 3.6.3.1 [basic.start.term]

[2] In C++11 statics are initialized in a thread safe way, this is also known as Magic Statics.

C# : Out of Memory exception

While the GC compacts the small object heap as part of an optimization strategy to eliminate memory holes, the GC never compacts the large object heap for performance reasons**(the cost of compaction is too high for large objects (greater than 85KB in size))**. Hence if you are running a program that uses many large objects in an x86 system, you might encounter OutOfMemory exceptions. If you are running that program in an x64 system, you might have a fragmented heap.

regex with space and letters only?

Allowed only characters & spaces. Ex : Jayant Lonari

if (!/^[a-zA-Z\s]+$/.test(NAME)) {
    //Throw Error
}

How to use jQuery with Angular?

If you use angular-cli you can do :

  1. Install the dependency :

    npm install jquery --save

    npm install @types/jquery --save-dev

  2. Import the file :

    Add "../node_modules/jquery/dist/jquery.min.js" to the "script" section in .angular-cli.json file

  3. Declare jquery :

    Add "$" to the "types" section of tsconfig.app.json

You can find more details on official angular cli doc

How to include a font .ttf using CSS?

I know this is an old post but this solved my problem.

_x000D_
_x000D_
@font-face{_x000D_
  font-family: "Font Name";_x000D_
  src: url("../fonts/font-name.ttf") format("truetype");_x000D_
}
_x000D_
_x000D_
_x000D_

notice src:url("../fonts/font-name.ttf"); we use two periods to go back to the root directory and then into the fonts folder or wherever your file is located.

hope this helps someone down the line:) happy coding

Chrome ignores autocomplete="off"

To prevent autocomplete, just set an empty space as the input value:

<input type="text" name="name" value="  ">

ORA-00904: invalid identifier

Also make sure the user issuing the query has been granted the necessary permissions.

For queries on tables you need to grant SELECT permission.
For queries on other object types (e.g. stored procedures) you need to grant EXECUTE permission.

popup form using html/javascript/css

Here is a resource you can edit and use Download Source Code or see live demo here http://purpledesign.in/blog/pop-out-a-form-using-jquery-and-javascript/

Add a Button or link to your page like this

<p><a href="#inline">click to open</a></p>

“#inline” here should be the “id” of the that will contain the form.

<div id="inline">
 <h2>Send us a Message</h2>
 <form id="contact" name="contact" action="#" method="post">
 <label for="email">Your E-mail</label>
 <input type="email" id="email" name="email" class="txt">
 <br>
 <label for="msg">Enter a Message</label>
 <textarea id="msg" name="msg" class="txtarea"></textarea>
<button id="send">Send E-mail</button>
 </form>
</div>

Include these script to listen of the event of click. If you have an action defined in your form you can use “preventDefault()” method

<script type="text/javascript">
 $(document).ready(function() {
$(".modalbox").fancybox();
$("#contact").submit(function() { return false; });
$("#send").on("click", function(){
var emailval = $("#email").val();
var msgval = $("#msg").val();
var msglen = msgval.length;
var mailvalid = validateEmail(emailval);
if(mailvalid == false) {
$("#email").addClass("error");
}
else if(mailvalid == true){
 $("#email").removeClass("error");
 }

 if(msglen < 4) {
 $("#msg").addClass("error");
 }
 else if(msglen >= 4){
 $("#msg").removeClass("error");
 }

 if(mailvalid == true && msglen >= 4) {
 // if both validate we attempt to send the e-mail
 // first we hide the submit btn so the user doesnt click twice
 $("#send").replaceWith("<em>sending...</em>");
 //This will post it to the php page
 $.ajax({
 type: 'POST',
 url: 'sendmessage.php',
 data: $("#contact").serialize(),
 success: function(data) {
 if(data == "true") {
 $("#contact").fadeOut("fast", function(){
//Display a message on successful posting for 1 sec
 $(this).before("<p><strong>Success! Your feedback has been sent, thanks :)</strong></p>");
 setTimeout("$.fancybox.close()", 1000);
 });
 }
 }
 });
 }
 });
 });
</script>

You can add anything you want to do in your PHP file.

printf formatting (%d versus %u)

The difference is simple: they cause different warning messages to be emitted when compiling:

1156942.c:7:31: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int *’ [-Wformat=]
     printf("memory address = %d\n", &a); // prints "memory add=-12"
                               ^
1156942.c:8:31: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 2 has type ‘int *’ [-Wformat=]
     printf("memory address = %u\n", &a); // prints "memory add=65456"
                               ^

If you pass your pointer as a void* and use %p as the conversion specifier, then you get no error message:

#include <stdio.h>

int main()
{
    int a = 5;
    // check the memory address
    printf("memory address = %d\n", &a); /* wrong */
    printf("memory address = %u\n", &a); /* wrong */
    printf("memory address = %p\n", (void*)&a); /* right */
}

Randomize numbers with jQuery?

Coding in Perl, I used the rand() function that generates the number at random and wanted only 1, 2, or 3 to be randomly selected. Due to Perl printing out the number one when doing "1 + " ... so I also did a if else statement that if the number generated zero, run the function again, and it works like a charm.

printing out the results will always give a random number of either 1, 2, or 3.

That is just another idea and sure people will say that is newbie stuff but at the same time, I am a newbie but it works. My issue was when printing out my stuff, it kept spitting out that 1 being used to start at 1 and not zero for indexing.

What use is find_package() if you need to specify CMAKE_MODULE_PATH anyway?

Command find_package has two modes: Module mode and Config mode. You are trying to use Module mode when you actually need Config mode.

Module mode

Find<package>.cmake file located within your project. Something like this:

CMakeLists.txt
cmake/FindFoo.cmake
cmake/FindBoo.cmake

CMakeLists.txt content:

list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
find_package(Foo REQUIRED) # FOO_INCLUDE_DIR, FOO_LIBRARIES
find_package(Boo REQUIRED) # BOO_INCLUDE_DIR, BOO_LIBRARIES

include_directories("${FOO_INCLUDE_DIR}")
include_directories("${BOO_INCLUDE_DIR}")
add_executable(Bar Bar.hpp Bar.cpp)
target_link_libraries(Bar ${FOO_LIBRARIES} ${BOO_LIBRARIES})

Note that CMAKE_MODULE_PATH has high priority and may be usefull when you need to rewrite standard Find<package>.cmake file.

Config mode (install)

<package>Config.cmake file located outside and produced by install command of other project (Foo for example).

foo library:

> cat CMakeLists.txt 
cmake_minimum_required(VERSION 2.8)
project(Foo)

add_library(foo Foo.hpp Foo.cpp)
install(FILES Foo.hpp DESTINATION include)
install(TARGETS foo DESTINATION lib)
install(FILES FooConfig.cmake DESTINATION lib/cmake/Foo)

Simplified version of config file:

> cat FooConfig.cmake 
add_library(foo STATIC IMPORTED)
find_library(FOO_LIBRARY_PATH foo HINTS "${CMAKE_CURRENT_LIST_DIR}/../../")
set_target_properties(foo PROPERTIES IMPORTED_LOCATION "${FOO_LIBRARY_PATH}")

By default project installed in CMAKE_INSTALL_PREFIX directory:

> cmake -H. -B_builds
> cmake --build _builds --target install
-- Install configuration: ""
-- Installing: /usr/local/include/Foo.hpp
-- Installing: /usr/local/lib/libfoo.a
-- Installing: /usr/local/lib/cmake/Foo/FooConfig.cmake

Config mode (use)

Use find_package(... CONFIG) to include FooConfig.cmake with imported target foo:

> cat CMakeLists.txt 
cmake_minimum_required(VERSION 2.8)
project(Boo)

# import library target `foo`
find_package(Foo CONFIG REQUIRED)

add_executable(boo Boo.cpp Boo.hpp)
target_link_libraries(boo foo)
> cmake -H. -B_builds -DCMAKE_VERBOSE_MAKEFILE=ON
> cmake --build _builds
Linking CXX executable Boo
/usr/bin/c++ ... -o Boo /usr/local/lib/libfoo.a

Note that imported target is highly configurable. See my answer.

Update

How to use BOOLEAN type in SELECT statement

How about using an expression which evaluates to TRUE (or FALSE)?

select get_something('NAME', 1 = 1) from dual

Upload a file to Amazon S3 with NodeJS

Thanks to David as his solution helped me come up with my solution for uploading multi-part files from my Heroku hosted site to S3 bucket. I did it using formidable to handle incoming form and fs to get the file content. Hopefully, it may help you.

api.service.ts

public upload(files): Observable<any> {  
    const formData: FormData = new FormData(); 
    files.forEach(file => {
      // create a new multipart-form for every file 
      formData.append('file', file, file.name);           
    });   
    return this.http.post(uploadUrl, formData).pipe(
      map(this.extractData),
      catchError(this.handleError)); 
  }
}

server.js

app.post('/api/upload', upload);
app.use('/api/upload', router);

upload.js

const IncomingForm = require('formidable').IncomingForm;
const fs = require('fs');
const AWS = require('aws-sdk');

module.exports = function upload(req, res) {
    var form = new IncomingForm();

    const bucket = new AWS.S3(
      {
        signatureVersion: 'v4',
        accessKeyId: process.env.AWS_ACCESS_KEY_ID,
        secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
        region: 'us-east-1'       
      }
    ); 

    form.on('file', (field, file) => {

        const fileContent = fs.readFileSync(file.path);

        const s3Params = {
            Bucket: process.env.AWS_S3_BUCKET,
            Key: 'folder/' + file.name,
            Expires: 60,             
            Body: fileContent,
            ACL: 'public-read'
        };

        bucket.upload(s3Params, function(err, data) {
            if (err) {
                throw err;
            }            
            console.log('File uploaded to: ' + data.Location);
            fs.unlink(file.path, function (err) {
              if (err) {
                  console.error(err);
              }
              console.log('Temp File Delete');
          });
        });
    });              

    // The second callback is called when the form is completely parsed. 
    // In this case, we want to send back a success status code.
    form.on('end', () => {        
      res.status(200).json('upload ok');
    });

    form.parse(req);
}

upload-image.component.ts

import { Component, OnInit, ViewChild, Output, EventEmitter, Input } from '@angular/core';
import { ApiService } from '../api.service';
import { MatSnackBar } from '@angular/material/snack-bar';

@Component({
  selector: 'app-upload-image',
  templateUrl: './upload-image.component.html',
  styleUrls: ['./upload-image.component.css']
})

export class UploadImageComponent implements OnInit {
  public files: Set<File> = new Set();
  @ViewChild('file', { static: false }) file;
  public uploadedFiles: Array<string> = new Array<string>();
  public uploadedFileNames: Array<string> = new Array<string>();
  @Output() filesOutput = new EventEmitter<Array<string>>();
  @Input() CurrentImage: string;
  @Input() IsPublic: boolean;
  @Output() valueUpdate = new EventEmitter();
  strUploadedFiles:string = '';
  filesUploaded: boolean = false;     

  constructor(private api: ApiService, public snackBar: MatSnackBar,) { }

  ngOnInit() {    
  }

  updateValue(val) {  
    this.valueUpdate.emit(val);  
  }  

  reset()
  {
    this.files = new Set();
    this.uploadedFiles = new Array<string>();
    this.uploadedFileNames = new Array<string>();
    this.filesUploaded = false;
  }

  upload() { 

    this.api.upload(this.files).subscribe(res => {   
      this.filesOutput.emit(this.uploadedFiles); 
      if (res == 'upload ok')
      {
        this.reset(); 
      }     
    }, err => {
      console.log(err);
    });
  }

  onFilesAdded() {
    var txt = '';
    const files: { [key: string]: File } = this.file.nativeElement.files;

    for (let key in files) {
      if (!isNaN(parseInt(key))) {

        var currentFile = files[key];
        var sFileExtension = currentFile.name.split('.')[currentFile.name.split('.').length - 1].toLowerCase();
        var iFileSize = currentFile.size;

        if (!(sFileExtension === "jpg" 
              || sFileExtension === "png") 
              || iFileSize > 671329) {
            txt = "File type : " + sFileExtension + "\n\n";
            txt += "Size: " + iFileSize + "\n\n";
            txt += "Please make sure your file is in jpg or png format and less than 655 KB.\n\n";
            alert(txt);
            return false;
        }

        this.files.add(files[key]);
        this.uploadedFiles.push('https://gourmet-philatelist-assets.s3.amazonaws.com/folder/' + files[key].name);
        this.uploadedFileNames.push(files[key].name);
        if (this.IsPublic && this.uploadedFileNames.length == 1)
        {
          this.filesUploaded = true;
          this.updateValue(files[key].name);
          break;
        } 
        else if (!this.IsPublic && this.uploadedFileNames.length == 3)
        {
          this.strUploadedFiles += files[key].name;          
          this.updateValue(this.strUploadedFiles); 
          this.filesUploaded = true;
          break;
        }
        else
        {
          this.strUploadedFiles += files[key].name + ",";          
          this.updateValue(this.strUploadedFiles); 
        }      
      }
    }    
  }

  addFiles() {
    this.file.nativeElement.click();  
  }

  openSnackBar(message: string, action: string) {
    this.snackBar.open(message, action, {
      duration: 2000,
      verticalPosition: 'top'
    });
  }   

}

upload-image.component.html

<input type="file" #file style="display: none" (change)="onFilesAdded()" multiple />
&nbsp;<button mat-raised-button color="primary" 
         [disabled]="filesUploaded" (click)="$event.preventDefault(); addFiles()">
  Add Files
</button>
&nbsp;<button class="btn btn-success" [disabled]="uploadedFileNames.length == 0" (click)="$event.preventDefault(); upload()">
  Upload
</button>

How to change status bar color in Flutter?

This one will also work

SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle.dark);
SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle.light);

need to test if sql query was successful

if you're not using the -> format, you can do this:

$a = "SQL command...";
if ($b = mysqli_query($con,$a)) {
  // results was successful
} else {
  // result was not successful
}

OWIN Startup Class Missing

While I can't fully explain why this solved the issue for me, I ran into a problem like this after I changed my API project to build to separate \debug and \release folders. Once I reverted that change back to build to a single \bin folder things started working.

I wrote up my experience here: Can't get the OWIN Startup class to run in IIS Express after renaming ASP.NET project file

Combining Two Images with OpenCV

You can also use OpenCV's inbuilt functions cv2.hconcat and cv2.vconcat which like their names suggest are used to join images horizontally and vertically respectively.

import cv2

img1 = cv2.imread('opencv/lena.jpg')
img2 = cv2.imread('opencv/baboon.jpg')

v_img = cv2.vconcat([img1, img2])
h_img = cv2.hconcat([img1, img2])

cv2.imshow('Horizontal', h_img)
cv2.imshow('Vertical', v_img)
cv2.waitKey(0)
cv2.destroyAllWindows()

Horizontal Concatenation

Horizontal

Vertical Concatenation

Vertical

CASE (Contains) rather than equal statement

CASE WHEN ', ' + dbo.Table.Column +',' LIKE '%, lactulose,%' 
  THEN 'BP Medication' ELSE '' END AS [BP Medication]

The leading ', ' and trailing ',' are added so that you can handle the match regardless of where it is in the string (first entry, last entry, or anywhere in between).

That said, why are you storing data you want to search on as a comma-separated string? This violates all kinds of forms and best practices. You should consider normalizing your schema.

In addition: don't use 'single quotes' as identifier delimiters; this syntax is deprecated. Use [square brackets] (preferred) or "double quotes" if you must. See "string literals as column aliases" here: http://msdn.microsoft.com/en-us/library/bb510662%28SQL.100%29.aspx

EDIT If you have multiple values, you can do this (you can't short-hand this with the other CASE syntax variant or by using something like IN()):

CASE 
  WHEN ', ' + dbo.Table.Column +',' LIKE '%, lactulose,%' 
  WHEN ', ' + dbo.Table.Column +',' LIKE '%, amlodipine,%' 
  THEN 'BP Medication' ELSE '' END AS [BP Medication]

If you have more values, it might be worthwhile to use a split function, e.g.

USE tempdb;
GO

CREATE FUNCTION dbo.SplitStrings(@List NVARCHAR(MAX))
RETURNS TABLE
AS
   RETURN ( SELECT DISTINCT Item FROM
       ( SELECT Item = x.i.value('(./text())[1]', 'nvarchar(max)')
         FROM ( SELECT [XML] = CONVERT(XML, '<i>'
         + REPLACE(@List,',', '</i><i>') + '</i>').query('.')
           ) AS a CROSS APPLY [XML].nodes('i') AS x(i) ) AS y
       WHERE Item IS NOT NULL
   );
GO

CREATE TABLE dbo.[Table](ID INT, [Column] VARCHAR(255));
GO

INSERT dbo.[Table] VALUES
(1,'lactulose, Lasix (furosemide), oxazepam, propranolol, rabeprazole, sertraline,'),
(2,'lactulite, Lasix (furosemide), lactulose, propranolol, rabeprazole, sertraline,'),
(3,'lactulite, Lasix (furosemide), oxazepam, propranolol, rabeprazole, sertraline,'),
(4,'lactulite, Lasix (furosemide), lactulose, amlodipine, rabeprazole, sertraline,');

SELECT t.ID
  FROM dbo.[Table] AS t
  INNER JOIN dbo.SplitStrings('lactulose,amlodipine') AS s
  ON ', ' + t.[Column] + ',' LIKE '%, ' + s.Item + ',%'
  GROUP BY t.ID;
GO

Results:

ID
----
1
2
4

Get the latest date from grouped MySQL data

This should work:

SELECT model, date FROM doc GROUP BY model ORDER BY date DESC

It just sort the dates from last to first and by grouping it only grabs the first one.

How do I display local image in markdown?

The following works with a relative path to an image into a subfolder next to the document (currently only tested on a Windows System):

![image info](./pictures/image.png)

How to install pywin32 module in windows 7

I had the exact same problem. The problem was that Anaconda had not registered Python in the windows registry.

1) pip install pywin
2) execute this script to register Python in the windows registry
3) download the appropriate package form Corey Goldberg's answer and python will be detected

add/remove active class for ul list with jquery?

you can use siblings and removeClass method

$('.nav-link li').click(function() {
    $(this).addClass('active').siblings().removeClass('active');
});

Python code to remove HTML tags from a string

Python has several XML modules built in. The simplest one for the case that you already have a string with the full HTML is xml.etree, which works (somewhat) similarly to the lxml example you mention:

def remove_tags(text):
    return ''.join(xml.etree.ElementTree.fromstring(text).itertext())

How to check if the URL contains a given string?

You would use indexOf like this:

if(window.location.href.indexOf("franky") != -1){....}

Also notice the addition of href for the string otherwise you would do:

if(window.location.toString().indexOf("franky") != -1){....}

Get the element triggering an onclick event in jquery?

It's top google stackoverflow question, but all answers are not jQuery related!

$(".someclass").click(
    function(event)
    {
        console.log(event, this);
    }
);

'event' contains 2 important values:

event.currentTarget - element to which event is triggered ('.someclass' element)

event.target - element clicked (in case when inside '.someclass' [div] are other elements and you clicked on of them)

this - is set to triggered element ('.someclass'), but it's JavaScript element, not jQuery element, so if you want to use some jQuery function on it, you must first change it to jQuery element: $(this)

When your refresh the page and reload the scripts again; this method not work. You have to use jquery "unbind" method.

How to check for valid email address?

Email addresses are incredibly complicated. Here's a sample regex that will match every RFC822-valid address: http://www.ex-parrot.com/pdw/Mail-RFC822-Address.html

You'll notice that it's probably longer than the rest of your program. There are even whole modules for Perl with the purpose of validating email addresses. So you probably won't get anything that's 100% perfect as a regex while also being readable. Here's a sample recursive descent parser: http://cpansearch.perl.org/src/ABIGAIL/RFC-RFC822-Address-2009110702/lib/RFC/RFC822/Address.pm

but you'll need to decide whether you need perfect parsing or simple code.

What is the printf format specifier for bool?

In the tradition of itoa():

#define btoa(x) ((x)?"true":"false")

bool x = true;
printf("%s\n", btoa(x));

Java HTTP Client Request with defined timeout

The said method with highest up's by Laz is deprecated from version 4.3 onwards. Hence it would be better to user the Request Config Object and then build the HTTP Client

    private CloseableHttpClient createHttpClient()
        {
        CloseableHttpClient httpClient;
        CommonHelperFunctions helperFunctions = new CommonHelperFunctions();
        PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
        cm.setMaxTotal(306);
        cm.setDefaultMaxPerRoute(108);
        RequestConfig requestConfig = RequestConfig.custom()
            .setConnectTimeout(15000)
            .setSocketTimeout(15000).build();
        httpClient = HttpClients.custom()
            .setConnectionManager(cm)
            .setDefaultRequestConfig(requestConfig).build();
        return httpClient;
        }

The PoolingHttpClientConnectionManager is user to set the max default number of connections and the max number of conncetions per route. I have set it as 306 and 108 respectively. The default values will not be sufficient for most of the cases.

For setting Timeout: I have used the RequestConfig object. You can also set the property Connection Request Timeout for setting timeout for waiting for connection from Connection manager.

What's the meaning of exception code "EXC_I386_GPFLT"?

I'm seeing this error code in rotation crashes on Xcode 12.0 Beta 6, only on the iOS 14 simulator. It doesn't crash on my real device running iOS 13 though! So if you're running beta stuff and seeing rotation crashes in the simulator, maybe you just need to run on a real device with a non-beta iOS version.

Contain form within a bootstrap popover?

like this Working demo http://jsfiddle.net/7e2XU/21/show/# * Update: http://jsfiddle.net/kz5kjmbt/

 <div class="container">
    <div class="row" style="padding-top: 240px;"> <a href="#" class="btn btn-large btn-primary" rel="popover" data-content='
<form id="mainForm" name="mainForm" method="post" action="">
    <p>
        <label>Name :</label>
        <input type="text" id="txtName" name="txtName" />
    </p>
    <p>
        <label>Address 1 :</label>
        <input type="text" id="txtAddress" name="txtAddress" />
    </p>
    <p>
        <label>City :</label>
        <input type="text" id="txtCity" name="txtCity" />
    </p>
    <p>
        <input type="submit" name="Submit" value="Submit" />
    </p>
</form>
 data-placement="top" data-original-title="Fill in form">Open form</a>

    </div>
</div>

JavaScript code:

    $('a[rel=popover]').popover({
      html: 'true',
      placement: 'right'
    })

ScreenShot

working updated fiddle screenshot

Paging UICollectionView by cells, not screen

Approach 1: Collection View

flowLayout is UICollectionViewFlowLayout property

override func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {

    if let collectionView = collectionView {

        targetContentOffset.memory = scrollView.contentOffset
        let pageWidth = CGRectGetWidth(scrollView.frame) + flowLayout.minimumInteritemSpacing

        var assistanceOffset : CGFloat = pageWidth / 3.0

        if velocity.x < 0 {
            assistanceOffset = -assistanceOffset
        }

        let assistedScrollPosition = (scrollView.contentOffset.x + assistanceOffset) / pageWidth

        var targetIndex = Int(round(assistedScrollPosition))


        if targetIndex < 0 {
            targetIndex = 0
        }
        else if targetIndex >= collectionView.numberOfItemsInSection(0) {
            targetIndex = collectionView.numberOfItemsInSection(0) - 1
        }

        print("targetIndex = \(targetIndex)")

        let indexPath = NSIndexPath(forItem: targetIndex, inSection: 0)

        collectionView.scrollToItemAtIndexPath(indexPath, atScrollPosition: .Left, animated: true)
    }
}

Approach 2: Page View Controller

You could use UIPageViewController if it meets your requirements, each page would have a separate view controller.

How to put sshpass command inside a bash script?

Do which sshpass in your command line to get the absolute path to sshpass and replace it in the bash script.

You should also probably do the same with the command you are trying to run.

The problem might be that it is not finding it.

One time page refresh after first page load

When I meet this problem, I search to here but most of answers are trying to modify existing url. Here is another answer which works for me using localStorage.

<script type='text/javascript'>

(function()
{
  if( window.localStorage )
  {
    if( !localStorage.getItem('firstLoad') )
    {
      localStorage['firstLoad'] = true;
      window.location.reload();
    }  
    else
      localStorage.removeItem('firstLoad');
  }
})();

</script>

Saving response from Requests to file

You can use the response.text to write to a file:

import requests

files = {'f': ('1.pdf', open('1.pdf', 'rb'))}
response = requests.post("https://pdftables.com/api?&format=xlsx-single",files=files)
response.raise_for_status() # ensure we notice bad responses
file = open("resp_text.txt", "w")
file.write(response.text)
file.close()
file = open("resp_content.txt", "w")
file.write(response.text)
file.close()

How to auto adjust the <div> height according to content in it?

I've used the following in the DIV that needs to be resized:

overflow: hidden;
height: 1%;

Delete an element from a dictionary

… how can I delete an item from a dictionary to return a copy (i.e., not modifying the original)?

A dict is the wrong data structure to use for this.

Sure, copying the dict and popping from the copy works, and so does building a new dict with a comprehension, but all that copying takes time—you've replaced a constant-time operation with a linear-time one. And all those copies alive at once take space—linear space per copy.

Other data structures, like hash array mapped tries, are designed for exactly this kind of use case: adding or removing an element returns a copy in logarithmic time, sharing most of its storage with the original.1

Of course there are some downsides. Performance is logarithmic rather than constant (although with a large base, usually 32-128). And, while you can make the non-mutating API identical to dict, the "mutating" API is obviously different. And, most of all, there's no HAMT batteries included with Python.2

The pyrsistent library is a pretty solid implementation of HAMT-based dict-replacements (and various other types) for Python. It even has a nifty evolver API for porting existing mutating code to persistent code as smoothly as possible. But if you want to be explicit about returning copies rather than mutating, you just use it like this:

>>> from pyrsistent import m
>>> d1 = m(a=1, b=2)
>>> d2 = d1.set('c', 3)
>>> d3 = d1.remove('a')
>>> d1
pmap({'a': 1, 'b': 2})
>>> d2
pmap({'c': 3, 'a': 1, 'b': 2})
>>> d3
pmap({'b': 2})

That d3 = d1.remove('a') is exactly what the question is asking for.

If you've got mutable data structures like dict and list embedded in the pmap, you'll still have aliasing issues—you can only fix that by going immutable all the way down, embedding pmaps and pvectors.


1. HAMTs have also become popular in languages like Scala, Clojure, Haskell because they play very nicely with lock-free programming and software transactional memory, but neither of those is very relevant in Python.

2. In fact, there is an HAMT in the stdlib, used in the implementation of contextvars. The earlier withdrawn PEP explains why. But this is a hidden implementation detail of the library, not a public collection type.

Prevent a webpage from navigating away using JavaScript

Unlike other methods presented here, this bit of code will not cause the browser to display a warning asking the user if he wants to leave; instead, it exploits the evented nature of the DOM to redirect back to the current page (and thus cancel navigation) before the browser has a chance to unload it from memory.

Since it works by short-circuiting navigation directly, it cannot be used to prevent the page from being closed; however, it can be used to disable frame-busting.

(function () {
    var location = window.document.location;

    var preventNavigation = function () {
        var originalHashValue = location.hash;

        window.setTimeout(function () {
            location.hash = 'preventNavigation' + ~~ (9999 * Math.random());
            location.hash = originalHashValue;
        }, 0);
    };

    window.addEventListener('beforeunload', preventNavigation, false);
    window.addEventListener('unload', preventNavigation, false);
})();

Disclaimer: You should never do this. If a page has frame-busting code on it, please respect the wishes of the author.

Auto-refreshing div with jQuery - setTimeout or another method?

$(document).ready(function() {
  $.ajaxSetup({ cache: false }); // This part addresses an IE bug.  without it, IE will only load the first number and will never refresh
  setInterval(function() {
    $('#notice_div').load('response.php');
  }, 3000); // the "3000" 
});

How to set environment via `ng serve` in Angular 6

You can use command ng serve -c dev for development environment ng serve -c prod for production environment

while building also same applies. You can use ng build -c dev for dev build

app.config for a class library

You generally should not add an app.config file to a class library project; it won't be used without some painful bending and twisting on your part. It doesn't hurt the library project at all - it just won't do anything at all.

Instead, you configure the application which is using your library; so the configuration information required would go there. Each application that might use your library likely will have different requirements, so this actually makes logical sense, too.

Count number of columns in a table row

Why not use reduce so that we can take colspan into account? :)

function getColumns(table) {
    var cellsArray = [];
    var cells = table.rows[0].cells;

    // Cast the cells to an array
    // (there are *cooler* ways of doing this, but this is the fastest by far)
    // Taken from https://stackoverflow.com/a/15144269/6424295
    for(var i=-1, l=cells.length; ++i!==l; cellsArray[i]=cells[i]);

    return cellsArray.reduce(
        (cols, cell) =>
            // Check if the cell is visible and add it / ignore it
            (cell.offsetParent !== null) ? cols += cell.colSpan : cols,
        0
    );
}

How to preview a part of a large pandas DataFrame, in iPython notebook?

You can just use nrows. For instance

pd.read_csv('data.csv',nrows=6)

will show the first 6 rows from data.csv.

How to use sha256 in php5.3.0

A way better solution is to just use the excelent compatibility script from Anthony Ferrara:

https://github.com/ircmaxell/password_compat

Please, and also, when checking the password, always add a way (preferibly async, so it doesn't impact the check process for timming attacks) to update the hash if needed.

css h1 - only as wide as the text

An easy fix for this is to float your H1 element left:

.centercol h1{
    background: #F2EFE9;
    border-left: 3px solid #C6C1B8;
    color: #006BB6;
    display: block;
    float: left;
    font-weight: normal;
    font-size: 18px;
    padding: 3px 3px 3px 6px;
}

I have put together a simple jsfiddle example that shows the effect of the "float: left" style on the width of your H1 element for anyone looking for a more generic answer:

http://jsfiddle.net/zmEBt/1/

How do I access an access array item by index in handlebars?

Try this:

<ul id="luke_should_be_here">
{{people.1.name}}
</ul>

How can I initialize C++ object member variables in the constructor?

I know this is 5 years later, but the replies above don't address what was wrong with your software. (Well, Yuushi's does, but I didn't realise until I had typed this - doh!). They answer the question in the title How can I initialize C++ object member variables in the constructor? This is about the other questions: Am I using the right approach but the wrong syntax? Or should I be coming at this from a different direction?

Programming style is largely a matter of opinion, but an alternative view to doing as much as possible in a constructor is to keep constructors down to a bare minimum, often having a separate initialization function. There is no need to try to cram all initialization into a constructor, never mind trying to force things at times into the constructors initialization list.

So, to the point, what was wrong with your software?

private:
    ThingOne* ThingOne;
    ThingTwo* ThingTwo;

Note that after these lines, ThingOne (and ThingTwo) now have two meanings, depending on context.

Outside of BigMommaClass, ThingOne is the class you created with #include "ThingOne.h"

Inside BigMommaClass, ThingOne is a pointer.

That is assuming the compiler can even make sense of the lines and doesn't get stuck in a loop thinking that ThingOne is a pointer to something which is itself a pointer to something which is a pointer to ...

Later, when you write

this->ThingOne = ThingOne(100);
this->ThingTwo = ThingTwo(numba1, numba2);

bear in mind that inside of BigMommaClass your ThingOne is a pointer.

If you change the declarations of the pointers to include a prefix (p)

private:
    ThingOne* pThingOne;
    ThingTwo* pThingTwo;

Then ThingOne will always refer to the class and pThingOne to the pointer.

It is then possible to rewrite

this->ThingOne = ThingOne(100);
this->ThingTwo = ThingTwo(numba1, numba2);

as

pThingOne = new ThingOne(100);
pThingTwo = new ThingTwo(numba1, numba2);

which corrects two problems: the double meaning problem, and the missing new. (You can leave this-> if you like!)

With that in place, I can add the following lines to a C++ program of mine and it compiles nicely.

class ThingOne{public:ThingOne(int n){};};
class ThingTwo{public:ThingTwo(int x, int y){};};

class BigMommaClass {

    public:
            BigMommaClass(int numba1, int numba2);

    private:
            ThingOne* pThingOne;
            ThingTwo* pThingTwo;
};

BigMommaClass::BigMommaClass(int numba1, int numba2)
{
    pThingOne = new ThingOne(numba1 + numba2);
    pThingTwo = new ThingTwo(numba1, numba2);
};

When you wrote

this->ThingOne = ThingOne(100);
this->ThingTwo = ThingTwo(numba1, numba2);

the use of this-> tells the compiler that the left hand side ThingOne is intended to mean the pointer. However we are inside BigMommaClass at the time and it's not necessary.

The problem is with the right hand side of the equals where ThingOne is intended to mean the class. So another way to rectify your problems would have been to write

this->ThingOne = new ::ThingOne(100);
this->ThingTwo = new ::ThingTwo(numba1, numba2);

or simply

ThingOne = new ::ThingOne(100);
ThingTwo = new ::ThingTwo(numba1, numba2);

using :: to change the compiler's interpretation of the identifier.

Delete last N characters from field in a SQL Server database

I got the answer to my own question, ant this is:

select reverse(stuff(reverse('a,b,c,d,'), 1, N, ''))

Where N is the number of characters to remove. This avoids to write the complex column/string twice

Update Angular model after setting input value with jQuery

I made modifications on only controller initialization by adding listener on action button:

$(document).on('click', '#action-button', function () {
        $timeout(function () {
             angular.element($('#input')).triggerHandler('input');
        });
});

Other solutions did not work in my case.

How can I check if given int exists in array?

int index = std::distance(std::begin(myArray), std::find(begin(myArray), end(std::myArray), VALUE));

Returns an invalid index (length of the array) if not found.

Passing 'this' to an onclick event

The code that you have would work, but is executed from the global context, which means that this refers to the global object.

<script type="text/javascript">
var foo = function(param) {
    param.innerHTML = "Not a button";
};
</script>
<button onclick="foo(this)" id="bar">Button</button>

You can also use the non-inline alternative, which attached to and executed from the specific element context which allows you to access the element from this.

<script type="text/javascript">
document.getElementById('bar').onclick = function() {
    this.innerHTML = "Not a button";
};
</script>
<button id="bar">Button</button>

Yarn: How to upgrade yarn version using terminal?

npm install --global yarn
npm upgrade --global yarn 

This should work.

What are these attributes: `aria-labelledby` and `aria-hidden`

The primary consumers of these properties are user agents such as screen readers for blind people. So in the case with a Bootstrap modal, the modal's div has role="dialog". When the screen reader notices that a div becomes visible which has this role, it'll speak the label for that div.

There are lots of ways to label things (and a few new ones with ARIA), but in some cases it is appropriate to use an existing element as a label (semantic) without using the <label> HTML tag. With HTML modals the label is usually a <h> header. So in the Bootstrap modal case, you add aria-labelledby=[IDofModalHeader], and the screen reader will speak that header when the modal appears.

Generally speaking a screen reader is going to notice whenever DOM elements become visible or invisible, so the aria-hidden property is frequently redundant and can probably be skipped in most cases.

LIKE vs CONTAINS on SQL Server

Having run both queries on a SQL Server 2012 instance, I can confirm the first query was fastest in my case.

The query with the LIKE keyword showed a clustered index scan.

The CONTAINS also had a clustered index scan with additional operators for the full text match and a merge join.

Plan

Size of character ('a') in C/C++

As Paul stated, it's because 'a' is an int in C but a char in C++.

I cover that specific difference between C and C++ in something I wrote a few years ago, at: http://david.tribble.com/text/cdiffs.htm

How to write files to assets folder or raw folder in android?

Why not update the files on the local file system instead? You can read/write files into your applications sandboxed area.

http://developer.android.com/guide/topics/data/data-storage.html#filesInternal

Other alternatives you may want to look into are Shared Perferences and using Cache Files (all described at the link above)

SQL Query for Selecting Multiple Records

You're looking for the IN() clause:

SELECT * FROM `Buses` WHERE `BusID` IN (1,2,3,5,7,9,11,44,88,etc...);

What's is the difference between include and extend in use case diagram?

Let's make this clearer. We use include every time we want to express the fact that the existence of one case depends on the existence of another.

EXAMPLES:

A user can do shopping online only after he has logged in his account. In other words, he can't do any shopping until he has logged in his account.

A user can't download from a site before the material had been uploaded. So, I can't download if nothing has been uploaded.

Do you get it?

It's about conditioned consequence. I can't do this if previously I didn't do that.

At least, I think this is the right way we use Include. I tend to think the example with Laptop and warranty from right above is the most convincing!

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

How about:

public override int GetHashCode()
{
    return string.Format("{0}_{1}_{2}", prop1, prop2, prop3).GetHashCode();
}

Assuming performance is not an issue :)

How to Convert Boolean to String

Just wanted to update, in PHP >= 5.50 you can do boolval() to do the same thing

Reference Here.

Java: Replace all ' in a string with \'

You have to first escape the backslash because it's a literal (yielding \\), and then escape it again because of the regular expression (yielding \\\\). So, Try:

 s.replaceAll("'", "\\\\'");

output:

You\'ll be totally awesome, I\'m really terrible

In java how to get substring from a string till a character c?

Here is code which returns a substring from a String until any of a given list of characters:

/**
 * Return a substring of the given original string until the first appearance
 * of any of the given characters.
 * <p>
 * e.g. Original "ab&cd-ef&gh"
 * 1. Separators {'&', '-'}
 * Result: "ab"
 * 2. Separators {'~', '-'}
 * Result: "ab&cd"
 * 3. Separators {'~', '='}
 * Result: "ab&cd-ef&gh"
 *
 * @param original   the original string
 * @param characters the separators until the substring to be considered
 * @return the substring or the original string of no separator exists
 */
public static String substringFirstOf(String original, List<Character> characters) {
    return characters.stream()
            .map(original::indexOf)
            .filter(min -> min > 0)
            .reduce(Integer::min)
            .map(position -> original.substring(0, position))
            .orElse(original);
}

increment date by one month

 <?php
              $selectdata ="select fromd,tod  from register where username='$username'";
            $q=mysqli_query($conm,$selectdata);
            $row=mysqli_fetch_array($q);

            $startdate=$row['fromd']; 
            $stdate=date('Y', strtotime($startdate));  

            $endate=$row['tod']; 
            $enddate=date('Y', strtotime($endate));  

            $years = range ($stdate,$enddate);
            echo '<select name="years" class="form-control">';
            echo '<option>SELECT</option>';
            foreach($years as $year)
              {   echo '<option value="'.$year.'"> '.$year.' </option>';  }
                echo '</select>'; ?>

Changes in import statement python3

For relative imports see the documentation. A relative import is when you import from a module relative to that module's location, instead of absolutely from sys.path.

As for import *, Python 2 allowed star imports within functions, for instance:

>>> def f():
...     from math import *
...     print sqrt

A warning is issued for this in Python 2 (at least recent versions). In Python 3 it is no longer allowed and you can only do star imports at the top level of a module (not inside functions or classes).

Automatically size JPanel inside JFrame

As other posters have said, you need to change the LayoutManager being used. I always preferred using a GridLayout so your code would become:

MainPanel mainPanel = new MainPanel();
JFrame mainFrame = new JFrame();
mainFrame.setLayout(new GridLayout());
mainFrame.pack();
mainFrame.setVisible(true);

GridLayout seems more conceptually correct to me when you want your panel to take up the entire screen.

Combining CSS Pseudo-elements, ":after" the ":last-child"

An old thread, nonetheless someone may benefit from this:

li:not(:last-child)::after { content: ","; }
li:last-child::after { content: "."; }

This should work in CSS3 and [untested] CSS2.

How do I convert NSMutableArray to NSArray?

Objective-C

Below is way to convert NSMutableArray to NSArray:

//oldArray is having NSMutableArray data-type.
//Using Init with Array method.
NSArray *newArray1 = [[NSArray alloc]initWithArray:oldArray];

//Make copy of array
NSArray *newArray2 = [oldArray copy];

//Make mutablecopy of array
NSArray *newArray3 = [oldArray mutableCopy];

//Directly stored NSMutableArray to NSArray.
NSArray *newArray4 = oldArray;

Swift

In Swift 3.0 there is new data type Array. Declare Array using let keyword then it would become NSArray And if declare using var keyword then it's become NSMutableArray.

Sample code:

let newArray = oldArray as Array

How to use operator '-replace' in PowerShell to replace strings of texts with special characters and replace successfully

'-replace' does a regex search and you have special characters in that last one (like +) So you might use the non-regex replace version like this:

$c = $c.replace('AccountKey=eKkij32jGEIYIEqAR5RjkKgf4OTiMO6SAyF68HsR/Zd/KXoKvSdjlUiiWyVV2+OUFOrVsd7jrzhldJPmfBBpQA==','DdOegAhDmLdsou6Ms6nPtP37bdw6EcXucuT47lf9kfClA6PjGTe3CfN+WVBJNWzqcQpWtZf10tgFhKrnN48lXA==')

Is there a JSON equivalent of XQuery/XPath?

Just to add to the choices, there's also XPath. XPath 3.1 handles JSON as well as XML. In XPath 3.1 your required query is ?0?Objects?*[?id=3]

How do you implement a good profanity filter?

Don't. It just leads to problems. One clbuttic personal experience I have with profanity filters is the time where I was kick/banned from an IRC channel for mentioning that I was "heading over the bridge to Hancock for a couple hours" or something to that effect.

Check if value exists in the array (AngularJS)

You can use indexOf(). Like:

var Color = ["blue", "black", "brown", "gold"];
var a = Color.indexOf("brown");
alert(a);

The indexOf() method searches the array for the specified item, and returns its position. And return -1 if the item is not found.


If you want to search from end to start, use the lastIndexOf() method:

    var Color = ["blue", "black", "brown", "gold"];
    var a = Color.lastIndexOf("brown");
    alert(a);

The search will start at the specified position, or at the end if no start position is specified, and end the search at the beginning of the array.

Returns -1 if the item is not found.

Undefined reference to pthread_create in Linux

in eclipse

properties->c/c++Build->setting->GCC C++ linker->libraries in top part add "pthread"

How do I run a program with commandline arguments using GDB within a Bash script?

You could create a file with context:

run arg1 arg2 arg3 etc

program input

And call gdb like

gdb prog < file

What does "The following object is masked from 'package:xxx'" mean?

The message means that both the packages have functions with the same names. In this particular case, the testthat and assertive packages contain five functions with the same name.

When two functions have the same name, which one gets called?

R will look through the search path to find functions, and will use the first one that it finds.

search()
 ##  [1] ".GlobalEnv"        "package:assertive" "package:testthat" 
 ##  [4] "tools:rstudio"     "package:stats"     "package:graphics" 
 ##  [7] "package:grDevices" "package:utils"     "package:datasets" 
 ## [10] "package:methods"   "Autoloads"         "package:base"

In this case, since assertive was loaded after testthat, it appears earlier in the search path, so the functions in that package will be used.

is_true
## function (x, .xname = get_name_in_parent(x)) 
## {
##     x <- coerce_to(x, "logical", .xname)
##     call_and_name(function(x) {
##         ok <- x & !is.na(x)
##         set_cause(ok, ifelse(is.na(x), "missing", "false"))
##     }, x)
## }
<bytecode: 0x0000000004fc9f10>
<environment: namespace:assertive.base>

The functions in testthat are not accessible in the usual way; that is, they have been masked.

What if I want to use one of the masked functions?

You can explicitly provide a package name when you call a function, using the double colon operator, ::. For example:

testthat::is_true
## function () 
## {
##     function(x) expect_true(x)
## }
## <environment: namespace:testthat>

How do I suppress the message?

If you know about the function name clash, and don't want to see it again, you can suppress the message by passing warn.conflicts = FALSE to library.

library(testthat)
library(assertive, warn.conflicts = FALSE)
# No output this time

Alternatively, suppress the message with suppressPackageStartupMessages:

library(testthat)
suppressPackageStartupMessages(library(assertive))
# Also no output

Impact of R's Startup Procedures on Function Masking

If you have altered some of R's startup configuration options (see ?Startup) you may experience different function masking behavior than you might expect. The precise order that things happen as laid out in ?Startup should solve most mysteries.

For example, the documentation there says:

Note that when the site and user profile files are sourced only the base package is loaded, so objects in other packages need to be referred to by e.g. utils::dump.frames or after explicitly loading the package concerned.

Which implies that when 3rd party packages are loaded via files like .Rprofile you may see functions from those packages masked by those in default packages like stats, rather than the reverse, if you loaded the 3rd party package after R's startup procedure is complete.

How do I list all the masked functions?

First, get a character vector of all the environments on the search path. For convenience, we'll name each element of this vector with its own value.

library(dplyr)
envs <- search() %>% setNames(., .)

For each environment, get the exported functions (and other variables).

fns <- lapply(envs, ls)

Turn this into a data frame, for easy use with dplyr.

fns_by_env <- data_frame(
  env = rep.int(names(fns), lengths(fns)),
  fn  = unlist(fns)
)

Find cases where the object appears more than once.

fns_by_env %>% 
  group_by(fn) %>% 
  tally() %>% 
  filter(n > 1) %>% 
  inner_join(fns_by_env)

To test this, try loading some packages with known conflicts (e.g., Hmisc, AnnotationDbi).

How do I prevent name conflict bugs?

The conflicted package throws an error with a helpful error message, whenever you try to use a variable with an ambiguous name.

library(conflicted)
library(Hmisc)
units
## Error: units found in 2 packages. You must indicate which one you want with ::
##  * Hmisc::units
##  * base::units

Spring MVC - How to return simple String as JSON in Rest Controller

Make simple:

    @GetMapping("/health")
    public ResponseEntity<String> healthCheck() {
        LOG.info("REST request health check");
        return new ResponseEntity<>("{\"status\" : \"UP\"}", HttpStatus.OK);
    }

Insert a background image in CSS (Twitter Bootstrap)

body {
    background-image: url(your image link);
    background-position: center center;
    background-repeat: no-repeat;
    background-attachment:fixed;
    background-size: cover;
    background-color: #464646;
}

SASS :not selector

I tried re-creating this, and .someclass.notip was being generated for me but .someclass:not(.notip) was not, for as long as I did not have the @mixin tip() defined. Once I had that, it all worked.

http://sassmeister.com/gist/9775949

$dropdown-width: 100px;
$comp-tip: true;

@mixin tip($pos:right) {

}

@mixin dropdown-pos($pos:right) {
  &:not(.notip) {
    @if $comp-tip == true{
      @if $pos == right {
        top:$dropdown-width * -0.6;
        background-color: #f00;
        @include tip($pos:$pos);
      }
    }
  }
  &.notip {
    @if $pos == right {
      top: 0;
      left:$dropdown-width * 0.8;
      background-color: #00f;
    }
  }
}

.someclass { @include dropdown-pos(); }

EDIT: http://sassmeister.com/ is a good place to debug your SASS because it gives you error messages. Undefined mixin 'tip'. it what I get when I remove @mixin tip($pos:right) { }

Generate random number between two numbers in JavaScript

Math is not my strong point, but I've been working on a project where I needed to generate a lot of random numbers between both positive and negative.

function randomBetween(min, max) {
    if (min < 0) {
        return min + Math.random() * (Math.abs(min)+max);
    }else {
        return min + Math.random() * max;
    }
}

E.g

randomBetween(-10,15)//or..
randomBetween(10,20)//or...
randomBetween(-200,-100)

Of course, you can also add some validation to make sure you don't do this with anything other than numbers. Also make sure that min is always less than or equal to max.

Difference between Pig and Hive? Why have both?

You can achieve similar results with pig/hive queries. The main difference lies within approach to understanding/writing/creating queries.

Pig tends to create a flow of data: small steps where in each you do some processing
Hive gives you SQL-like language to operate on your data, so transformation from RDBMS is much easier (Pig can be easier for someone who had not earlier experience with SQL)

It is also worth noting, that for Hive you can nice interface to work with this data (Beeswax for HUE, or Hive web interface), and it also gives you metastore for information about your data (schema, etc) which is useful as a central information about your data.

I use both Hive and Pig, for different queries (I use that one where I can write query faster/easier, I do it this way mostly ad-hoc queries) - they can use the same data as an input. But currently I'm doing much of my work through Beeswax.

PHP ternary operator vs null coalescing operator

Null Coalescing operator performs just two tasks: it checks whether the variable is set and whether it is null. Have a look at the following example:

<?php
# case 1:
$greeting = 'Hola';
echo $greeting ?? 'Hi There'; # outputs: 'Hola'

# case 2:
$greeting = null;
echo $greeting ?? 'Hi There'; # outputs: 'Hi There'

# case 3:
unset($greeting);
echo $greeting ?? 'Hi There'; # outputs: 'Hi There'

The above code example states that Null Coalescing operator treats a non-existing variable and a variable which is set to NULL in the same way.

Null Coalescing operator is an improvement over the ternary operator. Have a look at the following code snippet comparing the two:

<?php /* example: checking for the $_POST field that goes by the name of 'fullname'*/
# in ternary operator
echo "Welcome ", (isset($_POST['fullname']) && !is_null($_POST['fullname']) ? $_POST['fullname'] : 'Mr. Whosoever.'); # outputs: Welcome Mr. Whosoever.
# in null coalecing operator
echo "Welcome ", ($_POST['fullname'] ?? 'Mr. Whosoever.'); # outputs: Welcome Mr. Whosoever.

So, the difference between the two is that Null Coalescing operator operator is designed to handle undefined variables better than the ternary operator. Whereas, the ternary operator is a shorthand for if-else.

Null Coalescing operator is not meant to replace ternary operator, but in some use cases like in the above example, it allows you to write clean code with less hassle.

Credits: http://dwellupper.io/post/6/php7-null-coalescing-operator-usage-and-examples

C++/CLI Converting from System::String^ to std::string

Don't roll your own, use these handy (and extensible) wrappers provided by Microsoft.

For example:

#include <msclr\marshal_cppstd.h>

System::String^ managed = "test";
std::string unmanaged = msclr::interop::marshal_as<std::string>(managed);

Content Security Policy: The page's settings blocked the loading of a resource

I managed to allow all my requisite sites with this header:

header("Content-Security-Policy: default-src *; style-src 'self' 'unsafe-inline'; font-src 'self' data:; script-src 'self' 'unsafe-inline' 'unsafe-eval' stackexchange.com");                    

Left/Right float button inside div

Change display:inline to display:inline-block

.test {
  width:200px;
  display:inline-block;
  overflow: auto;
  white-space: nowrap;
  margin:0px auto;
  border:1px red solid;
}

how to drop database in sqlite?

You can drop tables by issuing an SQL Command as you would normally. If you want to drop the whole database you'll have to delete the file. You can delete the file located under

data/data/com.your.app.name/database/[databasefilename]

you can do this from the eclipse view called "FileBrowser" out of the "Android" Category for example. Or directly on your emulator or phone.

How to write Unicode characters to the console?

This works for me:

Console.OutputEncoding = System.Text.Encoding.Default;

To display some of the symbols, it's required to set Command Prompt's font to Lucida Console:

  1. Open Command Prompt;

  2. Right click on the top bar of the Command Prompt;

  3. Click Properties;

  4. If the font is set to Raster Fonts, change it to Lucida Console.