Programs & Examples On #Aptitude

Ubuntu apt-get unable to fetch packages

I have been fighting the same thing for a while.

after all the research, this is the best solution.....

add the following to your resolve.conf file /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4

https://serverfault.com/questions/717226/ubuntu14-04-unable-to-apt-get-update/771826#771826

Rails: How can I set default values in ActiveRecord?

I had a similar challenge when working on a Rails 6 application.

Here's how I solved it:

I have a Users table and a Roles table. The Users table belongs to the Roles table. I also have an Admin and Student Models that inherit from the Users table.

It then required that I set a default value for the role whenever a user is created, say admin role that has an id = 1 or student role that has an id = 2.

class User::Admin < User
  before_save :default_values

  def default_values
    # set role_id to '1' except if role_id is not empty
    return self.role_id = '1' unless role_id.nil?
  end
end

This means that before an admin user is created/saved in the database the role_id is set to a default of 1 if it is not empty.

return self.role_id = '1' unless role_id.nil? 

is the same as:

return self.role_id = '1' unless self.role_id.nil?

and the same as:

self.role_id = '1' if role_id.nil?

but the first one is cleaner and more precise.

That's all.

I hope this helps

loading json data from local file into React JS

You could add your JSON file as an external using webpack config. Then you can load up that json in any of your react modules.

Take a look at this answer

How to use JavaScript variables in jQuery selectors?

  1. ES6 String Template

    Here is a simple way if you don't need IE/EDGE support

    $(`input[id=${x}]`).hide();
    

    or

    $(`input[id=${$(this).attr("name")}]`).hide();
    

    This is a es6 feature called template string

    _x000D_
    _x000D_
        (function($) {_x000D_
            $("input[type=button]").click(function() {_x000D_
                var x = $(this).attr("name");_x000D_
                $(`input[id=${x}]`).toggle(); //use hide instead of toggle_x000D_
            });_x000D_
        })(jQuery);
    _x000D_
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
        <input type="text" id="bx" />_x000D_
        <input type="button" name="bx" value="1" />_x000D_
        <input type="text" id="by" />_x000D_
        <input type="button" name="by" value="2" />_x000D_
    _x000D_
     
    _x000D_
    _x000D_
    _x000D_


  1. String Concatenation

    If you need IE/EDGE support use

    $("#" + $(this).attr("name")).hide();
    

    _x000D_
    _x000D_
        (function($) {_x000D_
            $("input[type=button]").click(function() {_x000D_
                $("#" + $(this).attr("name")).toggle(); //use hide instead of toggle_x000D_
            });_x000D_
        })(jQuery);
    _x000D_
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
        <input type="text" id="bx" />_x000D_
        <input type="button" name="bx" value="1" />_x000D_
        <input type="text" id="by" />_x000D_
        <input type="button" name="by" value="2" />_x000D_
    _x000D_
     
    _x000D_
    _x000D_
    _x000D_


  1. Selector in DOM as data attribute

    This is my preferred way as it makes you code really DRY

    // HTML
    <input type="text"   id="bx" />
    <input type="button" data-input-sel="#bx" value="1" class="js-hide-onclick"/>
    
    //JS
    $($(this).data("input-sel")).hide();
    

    _x000D_
    _x000D_
        (function($) {_x000D_
            $(".js-hide-onclick").click(function() {_x000D_
                $($(this).data("input-sel")).toggle(); //use hide instead of toggle_x000D_
            });_x000D_
        })(jQuery);
    _x000D_
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
        <input type="text" id="bx" />_x000D_
        <input type="button" data-input-sel="#bx" value="1" class="js-hide-onclick" />_x000D_
        <input type="text" id="by" />_x000D_
        <input type="button" data-input-sel="#by" value="2" class="js-hide-onclick" />_x000D_
    _x000D_
     
    _x000D_
    _x000D_
    _x000D_

How to detect installed version of MS-Office?

Despite the fact that this question has been answered long time ago, I found some interesting facts to add that are related to the answers above.

As Dirk mentioned, there seems to be a weird fashion of version control from MS, starting from Office 365 / 2019. You cannot distinguish among the three(2016, 2019, O365), by seeing at the executable paths anymore. And just like he reputed himself, looking at the builds of the executable, as a mean of telling which is what, isn't quite effective either.

After some researching, I found a feasible solution. The solution lies under the registry subkey Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Licensing\LicensingNext.

So, my logic follows below:

Case 1: If the computer has the MSOffice 2016 installed, there is no subkeys under Licensing.

Case 2: if the computer has MSOffice 2019 installed, there is the name of the value (which is one of the Office Product ID). (e.g. Standard2019Volume)

Case 3: if the computer has Office365 installed, there is a value called o365bussinessretail(which is also a product ID) along with some other values.

The possible productIds are provided here.

To distinguish the three, I just opened the key and see if fails. If the open fails, its Office 2016. Then I enumerate LicensingNext and try to see if any name has a prefix o365, if it finds it then its O365. If it does not, then its Office 2019.

Frankly speaking, I did not have enough time to test the logic under varying environment. So please, note that.

Hope this will help whoever's interest.

Using Jasmine to spy on a function without an object

If you are defining your function:

function test() {};

Then, this is equivalent to:

window.test = function() {}  /* (in the browser) */

So spyOn(window, 'test') should work.

If that is not, you should also be able to:

test = jasmine.createSpy();

If none of those are working, something else is going on with your setup.

I don't think your fakeElement technique works because of what is going on behind the scenes. The original globalMethod still points to the same code. What spying does is proxy it, but only in the context of an object. If you can get your test code to call through the fakeElement it would work, but then you'd be able to give up global fns.

Is there a way to get version from package.json in nodejs code?

To determine the package version in node code, you can use the following:

  1. const version = require('./package.json').version; for < ES6 versions

  2. import {version} from './package.json'; for ES6 version

  3. const version = process.env.npm_package_version; if application has been started using npm start, all npm_* environment variables become available.

  4. You can use following npm packages as well - root-require, pkginfo, project-version.

How to add images in select list?

not exactly an image, but i found the easiest solution was to just add some unicode code in, ? works great for me

Error: TypeError: $(...).dialog is not a function

I had a similar problem and in my case, the issue was different (I am using Django templates).

The order of JS was incorrect (I know that's the first thing you check but I was almost sure that that was not the case, but it was). The js calling the dialog was called before jqueryUI library was called.

I am using Django, so was inheriting a template and using {{super.block}} to inherit code from the block as well to the template. I had to move {{super.block}} at the end of the block which solved the issue. The js calling the dialog was declared in the Media class in Django's admin.py. I spent more than an hour to figure it out. Hope this helps someone.

SQLite with encryption/password protection

You can get sqlite3.dll file with encryption support from http://system.data.sqlite.org/.

1 - Go to http://system.data.sqlite.org/index.html/doc/trunk/www/downloads.wiki and download one of the packages. .NET version is irrelevant here.

2 - Extract SQLite.Interop.dll from package and rename it to sqlite3.dll. This DLL supports encryption via plaintext passwords or encryption keys.

The mentioned file is native and does NOT require .NET framework. It might need Visual C++ Runtime depending on the package you have downloaded.

UPDATE

This is the package that I've downloaded for 32-bit development: http://system.data.sqlite.org/blobs/1.0.94.0/sqlite-netFx40-static-binary-Win32-2010-1.0.94.0.zip

html table span entire width?

Just FYI:

html should be table & width:100%. span should be margin: auto;

addEventListener in Internet Explorer

EDIT

I wrote a snippet that emulate the EventListener interface and the ie8 one, is callable even on plain objects: https://github.com/antcolag/iEventListener/blob/master/iEventListener.js

OLD ANSWER

this is a way for emulate addEventListener or attachEvent on browsers that don't support one of those
hope will help

(function (w,d) {  // 
    var
        nc  = "", nu    = "", nr    = "", t,
        a   = "addEventListener",
        n   = a in w,
        c   = (nc = "Event")+(n?(nc+= "", "Listener") : (nc+="Listener","") ),
        u   = n?(nu = "attach", "add"):(nu = "add","attach"),
        r   = n?(nr = "detach","remove"):(nr = "remove","detach")
/*
 * the evtf function, when invoked, return "attach" or "detach" "Event" functions if we are on a new browser, otherwise add "add" or "remove" "EventListener"
 */
    function evtf(whoe){return function(evnt,func,capt){return this[whoe]((n?((t = evnt.split("on"))[1] || t[0]) : ("on"+evnt)),func, (!n && capt? (whoe.indexOf("detach") < 0 ? this.setCapture() : this.removeCapture() ) : capt  ))}}
    w[nu + nc] = Element.prototype[nu + nc] = document[nu + nc] = evtf(u+c) // (add | attach)Event[Listener]
    w[nr + nc] = Element.prototype[nr + nc] = document[nr + nc] = evtf(r+c) // (remove | detach)Event[Listener]

})(window, document)

How can I update npm on Windows?

Use Upgrade npm on Windows

This is the official document for a user to upgrade npm on Windows!

Here is my screenshot!

Enter image description here

How do I download a file with Angular2 or greater

For those using Redux Pattern

I added in the file-saver as @Hector Cuevas named in his answer. Using Angular2 v. 2.3.1, I didn't need to add in the @types/file-saver.

The following example is to download a journal as PDF.

The journal actions

public static DOWNLOAD_JOURNALS = '[Journals] Download as PDF';
public downloadJournals(referenceId: string): Action {
 return {
   type: JournalActions.DOWNLOAD_JOURNALS,
   payload: { referenceId: referenceId }
 };
}

public static DOWNLOAD_JOURNALS_SUCCESS = '[Journals] Download as PDF Success';
public downloadJournalsSuccess(blob: Blob): Action {
 return {
   type: JournalActions.DOWNLOAD_JOURNALS_SUCCESS,
   payload: { blob: blob }
 };
}

The journal effects

@Effect() download$ = this.actions$
    .ofType(JournalActions.DOWNLOAD_JOURNALS)
    .switchMap(({payload}) =>
        this._journalApiService.downloadJournal(payload.referenceId)
        .map((blob) => this._actions.downloadJournalsSuccess(blob))
        .catch((err) => handleError(err, this._actions.downloadJournalsFail(err)))
    );

@Effect() downloadJournalSuccess$ = this.actions$
    .ofType(JournalActions.DOWNLOAD_JOURNALS_SUCCESS)
    .map(({payload}) => saveBlobAs(payload.blob, 'journal.pdf'))

The journal service

public downloadJournal(referenceId: string): Observable<any> {
    const url = `${this._config.momentumApi}/api/journals/${referenceId}/download`;
    return this._http.getBlob(url);
}

The HTTP service

public getBlob = (url: string): Observable<any> => {
    return this.request({
        method: RequestMethod.Get,
        url: url,
        responseType: ResponseContentType.Blob
    });
};

The journal reducer Though this only sets the correct states used in our application I still wanted to add it in to show the complete pattern.

case JournalActions.DOWNLOAD_JOURNALS: {
  return Object.assign({}, state, <IJournalState>{ downloading: true, hasValidationErrors: false, errors: [] });
}

case JournalActions.DOWNLOAD_JOURNALS_SUCCESS: {
  return Object.assign({}, state, <IJournalState>{ downloading: false, hasValidationErrors: false, errors: [] });
}

I hope this is helpful.

How to remove specific object from ArrayList in Java?

simple use remove() function. and pass object as param u want to remove. ur arraylist.remove(obj)

Case objects vs Enumerations in Scala

Update March 2017: as commented by Anthony Accioly, the scala.Enumeration/enum PR has been closed.

Dotty (next generation compiler for Scala) will take the lead, though dotty issue 1970 and Martin Odersky's PR 1958.


Note: there is now (August 2016, 6+ years later) a proposal to remove scala.Enumeration: PR 5352

Deprecate scala.Enumeration, add @enum annotation

The syntax

@enum
 class Toggle {
  ON
  OFF
 }

is a possible implementation example, intention is to also support ADTs that conform to certain restrictions (no nesting, recursion or varying constructor parameters), e. g.:

@enum
sealed trait Toggle
case object ON  extends Toggle
case object OFF extends Toggle

Deprecates the unmitigated disaster that is scala.Enumeration.

Advantages of @enum over scala.Enumeration:

  • Actually works
  • Java interop
  • No erasure issues
  • No confusing mini-DSL to learn when defining enumerations

Disadvantages: None.

This addresses the issue of not being able to have one codebase that supports Scala-JVM, Scala.js and Scala-Native (Java source code not supported on Scala.js/Scala-Native, Scala source code not able to define enums that are accepted by existing APIs on Scala-JVM).

Android ImageView Animation

Don't hard code image bounds. Just use:

RotateAnimation anim = new RotateAnimation( fromAngle, toAngle, imageView.getDrawable().getBounds().width()/2, imageView.getDrawable().getBounds().height()/2);

How do I use a regex in a shell script?

To complement the existing helpful answers:

Using Bash's own regex-matching operator, =~, is a faster alternative in this case, given that you're only matching a single value already stored in a variable:

set -- '12-34-5678' # set $1 to sample value

kREGEX_DATE='^[0-9]{2}[-/][0-9]{2}[-/][0-9]{4}$' # note use of [0-9] to avoid \d
[[ $1 =~ $kREGEX_DATE ]]
echo $? # 0 with the sample value, i.e., a successful match

Note, however, that the caveat re using flavor-specific regex constructs such as \d equally applies: While =~ supports EREs (extended regular expressions), it also supports the host platform's specific extension - it's a rare case of Bash's behavior being platform-dependent.

To remain portable (in the context of Bash), stick to the POSIX ERE specification.

Note that =~ even allows you to define capture groups (parenthesized subexpressions) whose matches you can later access through Bash's special ${BASH_REMATCH[@]} array variable.

Further notes:

  • $kREGEX_DATE is used unquoted, which is necessary for the regex to be recognized as such (quoted parts would be treated as literals).

  • While not always necessary, it is advisable to store the regex in a variable first, because Bash has trouble with regex literals containing \.

    • E.g., on Linux, where \< is supported to match word boundaries, [[ 3 =~ \<3 ]] && echo yes doesn't work, but re='\<3'; [[ 3 =~ $re ]] && echo yes does.
  • I've changed variable name REGEX_DATE to kREGEX_DATE (k signaling a (conceptual) constant), so as to ensure that the name isn't an all-uppercase name, because all-uppercase variable names should be avoided to prevent conflicts with special environment and shell variables.

Is there a Newline constant defined in Java like Environment.Newline in C#?

Be aware that this property isn't as useful as many people think it is. Just because your app is running on a Windows machine, for example, doesn't mean the file it's reading will be using Windows-style line separators. Many web pages contain a mixture of "\n" and "\r\n", having been cobbled together from disparate sources. When you're reading text as a series of logical lines, you should always look for all three of the major line-separator styles: Windows ("\r\n"), Unix/Linux/OSX ("\n") and pre-OSX Mac ("\r").

When you're writing text, you should be more concerned with how the file will be used than what platform you're running on. For example, if you expect people to read the file in Windows Notepad, you should use "\r\n" because it only recognizes the one kind of separator.

WordPress path url in js script file

If the javascript file is loaded from the admin dashboard, this javascript function will give you the root of your WordPress installation. I use this a lot when I'm building plugins that need to make ajax requests from the admin dashboard.

function getHomeUrl() {
  var href = window.location.href;
  var index = href.indexOf('/wp-admin');
  var homeUrl = href.substring(0, index);
  return homeUrl;
}

How do I sort an observable collection?

A variation is where you sort the collection in place using a selection sort algorithm. Elements are moved into place using the Move method. Each move will fire the CollectionChanged event with NotifyCollectionChangedAction.Move (and also PropertyChanged with property name Item[]).

This algorithm has some nice properties:

  • The algorithm can be implemented as a stable sort.
  • The number of items moved in the collection (e.g. CollectionChanged events fired) is almost always less than other similar algorithms like insertion sort and bubble sort.

The algorithm is quite simple. The collection is iterated to find the smallest element which is then moved to the start of the collection. The process is repeated starting at the second element and so on until all elements have been moved into place. The algorithm is not terribly efficient but for anything you are going to display in a user interface it shouldn't matter. However, in terms of the number of move operations it is quite efficient.

Here is an extension method that for simplicity requires that the elements implement IComparable<T>. Other options are using an IComparer<T> or a Func<T, T, Int32>.

public static class ObservableCollectionExtensions {

  public static void Sort<T>(this ObservableCollection<T> collection) where T : IComparable<T> {
    if (collection == null)
      throw new ArgumentNullException("collection");

    for (var startIndex = 0; startIndex < collection.Count - 1; startIndex += 1) {
      var indexOfSmallestItem = startIndex;
      for (var i = startIndex + 1; i < collection.Count; i += 1)
        if (collection[i].CompareTo(collection[indexOfSmallestItem]) < 0)
          indexOfSmallestItem = i;
      if (indexOfSmallestItem != startIndex)
        collection.Move(indexOfSmallestItem, startIndex);
    }
  }

}

Sorting a collection is simply a matter of invoking the extension method:

var collection = new ObservableCollection<String>(...);
collection.Sort();

When would you use the Builder Pattern?

Below are some reasons arguing for the use of the pattern and example code in Java, but it is an implementation of the Builder Pattern covered by the Gang of Four in Design Patterns. The reasons you would use it in Java are also applicable to other programming languages as well.

As Joshua Bloch states in Effective Java, 2nd Edition:

The builder pattern is a good choice when designing classes whose constructors or static factories would have more than a handful of parameters.

We've all at some point encountered a class with a list of constructors where each addition adds a new option parameter:

Pizza(int size) { ... }        
Pizza(int size, boolean cheese) { ... }    
Pizza(int size, boolean cheese, boolean pepperoni) { ... }    
Pizza(int size, boolean cheese, boolean pepperoni, boolean bacon) { ... }

This is called the Telescoping Constructor Pattern. The problem with this pattern is that once constructors are 4 or 5 parameters long it becomes difficult to remember the required order of the parameters as well as what particular constructor you might want in a given situation.

One alternative you have to the Telescoping Constructor Pattern is the JavaBean Pattern where you call a constructor with the mandatory parameters and then call any optional setters after:

Pizza pizza = new Pizza(12);
pizza.setCheese(true);
pizza.setPepperoni(true);
pizza.setBacon(true);

The problem here is that because the object is created over several calls it may be in an inconsistent state partway through its construction. This also requires a lot of extra effort to ensure thread safety.

The better alternative is to use the Builder Pattern.

public class Pizza {
  private int size;
  private boolean cheese;
  private boolean pepperoni;
  private boolean bacon;

  public static class Builder {
    //required
    private final int size;

    //optional
    private boolean cheese = false;
    private boolean pepperoni = false;
    private boolean bacon = false;

    public Builder(int size) {
      this.size = size;
    }

    public Builder cheese(boolean value) {
      cheese = value;
      return this;
    }

    public Builder pepperoni(boolean value) {
      pepperoni = value;
      return this;
    }

    public Builder bacon(boolean value) {
      bacon = value;
      return this;
    }

    public Pizza build() {
      return new Pizza(this);
    }
  }

  private Pizza(Builder builder) {
    size = builder.size;
    cheese = builder.cheese;
    pepperoni = builder.pepperoni;
    bacon = builder.bacon;
  }
}

Note that Pizza is immutable and that parameter values are all in a single location. Because the Builder's setter methods return the Builder object they are able to be chained.

Pizza pizza = new Pizza.Builder(12)
                       .cheese(true)
                       .pepperoni(true)
                       .bacon(true)
                       .build();

This results in code that is easy to write and very easy to read and understand. In this example, the build method could be modified to check parameters after they have been copied from the builder to the Pizza object and throw an IllegalStateException if an invalid parameter value has been supplied. This pattern is flexible and it is easy to add more parameters to it in the future. It is really only useful if you are going to have more than 4 or 5 parameters for a constructor. That said, it might be worthwhile in the first place if you suspect you may be adding more parameters in the future.

I have borrowed heavily on this topic from the book Effective Java, 2nd Edition by Joshua Bloch. To learn more about this pattern and other effective Java practices I highly recommend it.

Spring-Boot: How do I set JDBC pool properties like maximum number of connections?

It turns out setting these configuration properties is pretty straight forward, but the official documentation is more general so it might be hard to find when searching specifically for connection pool configuration information.

To set the maximum pool size for tomcat-jdbc, set this property in your .properties or .yml file:

spring.datasource.maxActive=5

You can also use the following if you prefer:

spring.datasource.max-active=5

You can set any connection pool property you want this way. Here is a complete list of properties supported by tomcat-jdbc.

To understand how this works more generally you need to dig into the Spring-Boot code a bit.

Spring-Boot constructs the DataSource like this (see here, line 102):

@ConfigurationProperties(prefix = DataSourceAutoConfiguration.CONFIGURATION_PREFIX)
@Bean
public DataSource dataSource() {
    DataSourceBuilder factory = DataSourceBuilder
            .create(this.properties.getClassLoader())
            .driverClassName(this.properties.getDriverClassName())
            .url(this.properties.getUrl())
            .username(this.properties.getUsername())
            .password(this.properties.getPassword());
    return factory.build();
}

The DataSourceBuilder is responsible for figuring out which pooling library to use, by checking for each of a series of know classes on the classpath. It then constructs the DataSource and returns it to the dataSource() function.

At this point, magic kicks in using @ConfigurationProperties. This annotation tells Spring to look for properties with prefix CONFIGURATION_PREFIX (which is spring.datasource). For each property that starts with that prefix, Spring will try to call the setter on the DataSource with that property.

The Tomcat DataSource is an extension of DataSourceProxy, which has the method setMaxActive().

And that's how your spring.datasource.maxActive=5 gets applied correctly!

What about other connection pools

I haven't tried, but if you are using one of the other Spring-Boot supported connection pools (currently HikariCP or Commons DBCP) you should be able to set the properties the same way, but you'll need to look at the project documentation to know what is available.

How to change text color of simple list item

Create an xml file in res/values and copy the below code

<style name="BlackText">
<item name="android:textColor">#000000</item>
</style>

and the specify the style in activity in Manifest like below

 android:theme="@style/BlackText"

Null or empty check for a string variable

declare @sexo as char(1)

select @sexo='F'

select * from pessoa

where isnull(Sexo,0) =isnull(@Sexo,0)

Merge (Concat) Multiple JSONObjects in Java

Today, I was also struggling to merge JSON objects and came with following solution (uses Gson library).

private JsonObject mergeJsons(List<JsonObject> jsonObjs) {
    JsonObject mergedJson = new JsonObject();
    jsonObjs.forEach((JsonObject jsonObj) -> {
        Set<Map.Entry<String, JsonElement>> entrySet = jsonObj.entrySet();
        entrySet.forEach((next) -> {
            mergedJson.add(next.getKey(), next.getValue());
        });
    });
    return mergedJson;
}

Java balanced expressions check {[()]}

    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Scanner;
    import java.util.Stack;
    public class BalancedParenthesisWithStack {

    /*This is purely Java Stack based solutions without using additonal 
      data structure like array/Map */

    public static void main(String[] args) throws IOException {

        Scanner sc = new Scanner(System.in);

        /*Take list of String inputs (parenthesis expressions both valid and 
         invalid from console*/

        List<String> inputs=new ArrayList<>();
        while (sc.hasNext()) {

            String input=sc.next();
            inputs.add(input);

        }

        //For every input in above list display whether it is valid or 
         //invalid parenthesis expression

        for(String input:inputs){



        System.out.println("\nisBalancedParenthesis:"+isBalancedParenthesis
        (input));
        }
    }

    //This method identifies whether expression is valid parenthesis or not

    public static boolean isBalancedParenthesis(String expression){

        //sequence of opening parenthesis according to its precedence
         //i.e. '[' has higher precedence than '{' or '('
        String openingParenthesis="[{(";

        //sequence of closing parenthesis according to its precedence
        String closingParenthesis=")}]";

        //Stack will be pushed on opening parenthesis and popped on closing.
        Stack<Character> parenthesisStack=new Stack<>();


          /*For expression to be valid :
          CHECK :
          1. it must start with opening parenthesis [()...
          2. precedence of parenthesis  should be proper (eg. "{[" invalid  
                                                              "[{(" valid  ) 


          3. matching pair if(  '(' => ')')  i.e. [{()}(())] ->valid [{)]not 
          */
         if(closingParenthesis.contains
         (((Character)expression.charAt(0)).toString())){
            return false;
        }else{
        for(int i=0;i<expression.length();i++){

        char ch= (Character)expression.charAt(i);

        //if parenthesis is opening(ie any of '[','{','(') push on stack
        if(openingParenthesis.contains(ch.toString())){
                parenthesisStack.push(ch);
            }else if(closingParenthesis.contains(ch.toString())){
        //if parenthesis is closing (ie any of ']','}',')') pop stack
        //depending upon check-3 
                if(parenthesisStack.peek()=='(' && (ch==')') || 
                    parenthesisStack.peek()=='{' && (ch=='}') ||    
                    parenthesisStack.peek()=='[' && (ch==']')
                        ){
                parenthesisStack.pop();
                }
            }
        }

        return (parenthesisStack.isEmpty())? true : false;
        }
    }

Visual Studio Code open tab in new window

With Visual Studio 1.43 (Q1 2020), the Ctrl+K then O keyboard shortcut will work for a file.

See issue 89989:

It should be possible to e.g. invoke the "Open Active File in New Window" command and open that file into an empty workspace in the web.

new windows -- https://user-images.githubusercontent.com/900690/73733120-aa0f6680-473b-11ea-8bcd-f2f71b75b496.png

How to run two jQuery animations simultaneously?

yes there is!

$(function () {
    $("#first").animate({
       width: '200px'
    }, { duration: 200, queue: false });

    $("#second").animate({
       width: '600px'
    }, { duration: 200, queue: false });
});

How to update an "array of objects" with Firestore?

Sorry Late to party but Firestore solved it way back in aug 2018 so If you still looking for that here it is all issues solved with regards to arrays.

https://firebase.googleblog.com/2018/08/better-arrays-in-cloud-firestore.htmlOfficial blog post

array-contains, arrayRemove, arrayUnion for checking, removing and updating arrays. Hope it helps.

GUI-based or Web-based JSON editor that works like property explorer

Generally when I want to create a JSON or YAML string, I start out by building the Perl data structure, and then running a simple conversion on it. You could put a UI in front of the Perl data structure generation, e.g. a web form.

Converting a structure to JSON is very straightforward:

use strict;
use warnings;
use JSON::Any;

my $data = { arbitrary structure in here };
my $json_handler = JSON::Any->new(utf8=>1);
my $json_string = $json_handler->objToJson($data);

Access a function variable outside the function without using "global"

I've experienced the same problem. One of the responds to your question led me to the following idea (which worked eventually). I use Python 3.7.

    # just an example 
    def func(): # define a function
       func.y = 4 # here y is a local variable, which I want to access; func.y defines 
                  # a method for my example function which will allow me to access 
                  # function's local variable y
       x = func.y + 8 # this is the main task for the function: what it should do
       return x

    func() # now I'm calling the function
    a = func.y # I put it's local variable into my new variable
    print(a) # and print my new variable

Then I launch this program in Windows PowerShell and get the answer 4. Conclusion: to be able to access a local function's variable one might add the name of the function and a dot before the name of the local variable (and then, of course, use this construction for calling the variable both in the function's body and outside of it). I hope this will help.

Switch on ranges of integers in JavaScript

    switch(this.dealer) {
        case 1:
        case 2:
        case 3:
        case 4:
            // Do something.
            break;
        case 5:
        case 6:
        case 7:
        case 8:
            // Do something.
            break;
        default:
            break;
    }

If you don't like the succession of cases, simply go for if/else if/else statements.

How do I get a computer's name and IP address using VB.NET?

Thanks Shuwaiee

I made a slight change though as using it in a Private Sub already.

Dim GetIPAddress()

Dim strHostName As String

Dim strIPAddress As String

strHostName = System.Net.Dns.GetHostName()

strIPAddress = System.Net.Dns.GetHostByName(strHostName).AddressList(0).ToString()

MessageBox.Show("Host Name: " & strHostName & vbCrLf & "IP Address: " & strIPAddress)

But also made a change to the way the details are displayed so that they can show on seperate lines using & vbCrLf &

MessageBox.Show("Host Name: " & strHostName & vbCrLf & "IP Address: " & strIPAddress)

Hope this helps someone.

Using JQuery to check if no radio button in a group has been checked

Use .length refer to http://api.jquery.com/checked-selector/

if ($('input[name="html_elements"]:checked').length === 0) alert("Not checked");
else alert("Checked");

ThreadStart with parameters

I propose using Task<T>instead of Thread; it allows multiple parameters and executes really fine.

Here is a working example:

    public static void Main()
    {
        List<Task> tasks = new List<Task>();

        Console.WriteLine("Awaiting threads to finished...");

        string par1 = "foo";
        string par2 = "boo";
        int par3 = 3;

        for (int i = 0; i < 1000; i++)
        {
            tasks.Add(Task.Run(() => Calculate(par1, par2, par3))); 
        }

        Task.WaitAll(tasks.ToArray());

        Console.WriteLine("All threads finished!");
    }

    static bool Calculate1(string par1, string par2, int par3)
    {
        lock(_locker)
        {
            //...
            return true;
        }
    }

    // if need to lock, use this:
    private static Object _locker = new Object();"

    static bool Calculate2(string par1, string par2, int par3)
    {
        lock(_locker)
        {
            //...
            return true;
        }
    }

Turning off some legends in a ggplot

You can use guide=FALSE in scale_..._...() to suppress legend.

For your example you should use scale_colour_continuous() because length is continuous variable (not discrete).

(p3 <- ggplot(mov, aes(year, rating, colour = length, shape = mpaa)) +
   scale_colour_continuous(guide = FALSE) +
   geom_point()
)

Or using function guides() you should set FALSE for that element/aesthetic that you don't want to appear as legend, for example, fill, shape, colour.

p0 <- ggplot(mov, aes(year, rating, colour = length, shape = mpaa)) +
  geom_point()    
p0+guides(colour=FALSE)

UPDATE

Both provided solutions work in new ggplot2 version 2.0.0 but movies dataset is no longer present in this library. Instead you have to use new package ggplot2movies to check those solutions.

library(ggplot2movies)
data(movies)
mov <- subset(movies, length != "")

How to style UITextview to like Rounded Rect text field?

One solution is to add a UITextField below the UITextView, make the UITextView background transparent and disable any user interaction on the UITextField. Then in code change the UITextField frame with something like that

self.textField.frame = CGRectInset(self.textView.frame, 0, -2);

You will have exactly the same look as a text field.

And as suggested by Jon, you should put this piece of code inside [UIViewController viewDidLayoutSubviews] on iOS 5.0+.

Making a cURL call in C#

Call cURL from your console app is not a good idea.

But you can use TinyRestClient which make easier to build requests :

var client = new TinyRestClient(new HttpClient(),"https://api.repustate.com/");

client.PostRequest("v2/demokey/score.json").
AddQueryParameter("text", "").
ExecuteAsync<MyResponse>();

How to create circular ProgressBar in android?

It's easy to create this yourself

In your layout include the following ProgressBar with a specific drawable (note you should get the width from dimensions instead). The max value is important here:

<ProgressBar
    android:id="@+id/progressBar"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:max="500"
    android:progress="0"
    android:progressDrawable="@drawable/circular" />

Now create the drawable in your resources with the following shape. Play with the radius (you can use innerRadius instead of innerRadiusRatio) and thickness values.

circular (Pre Lollipop OR API Level < 21)

   <shape
        android:innerRadiusRatio="2.3"
        android:shape="ring"
        android:thickness="3.8sp" >
        <solid android:color="@color/yourColor" />
   </shape>

circular ( >= Lollipop OR API Level >= 21)

    <shape
        android:useLevel="true"
        android:innerRadiusRatio="2.3"
        android:shape="ring"
        android:thickness="3.8sp" >
        <solid android:color="@color/yourColor" />
     </shape>

useLevel is "false" by default in API Level 21 (Lollipop) .

Start Animation

Next in your code use an ObjectAnimator to animate the progress field of the ProgessBar of your layout.

ProgressBar progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
ObjectAnimator animation = ObjectAnimator.ofInt(progressBar, "progress", 0, 500); // see this max value coming back here, we animate towards that value
animation.setDuration(5000); // in milliseconds
animation.setInterpolator(new DecelerateInterpolator());
animation.start();

Stop Animation

progressBar.clearAnimation();

P.S. unlike examples above, it give smooth animation.

How can I create a simple index.html file which lists all files/directories?

There's a free php script made by Celeron Dude that can do this called Celeron Dude Indexer 2. It doesn't require .htaccess The source code is easy to understand and provides a good starting point.

Here's a download link: https://gitlab.com/desbest/celeron-dude-indexer/

celeron dude indexer

How to load/edit/run/save text files (.py) into an IPython notebook cell?

EDIT: Starting from IPython 3 (now Jupyter project), the notebook has a text editor that can be used as a more convenient alternative to load/edit/save text files.

A text file can be loaded in a notebook cell with the magic command %load.

If you execute a cell containing:

%load filename.py

the content of filename.py will be loaded in the next cell. You can edit and execute it as usual.

To save the cell content back into a file add the cell-magic %%writefile filename.py at the beginning of the cell and run it. Beware that if a file with the same name already exists it will be silently overwritten.

To see the help for any magic command add a ?: like %load? or %%writefile?.

For general help on magic functions type "%magic" For a list of the available magic functions, use %lsmagic. For a description of any of them, type %magic_name?, e.g. '%cd?'.

See also: Magic functions from the official IPython docs.

Can't open file 'svn/repo/db/txn-current-lock': Permission denied

I just had this problem

  1. Having multiple user using the same repo caused the problem
  2. Logout evey other user using the repo

Hope this helps

Checking from shell script if a directory contains files

# Works on hidden files, directories and regular files
### isEmpty()
# This function takes one parameter:
# $1 is the directory to check
# Echoes "huzzah" if the directory has files
function isEmpty(){
  if [ "$(ls -A $1)" ]; then
    echo "huzzah"
  else 
    echo "has no files"
  fi
}

How can you print multiple variables inside a string using printf?

Change the line where you print the output to:

printf("\nmaximum of %d and %d is = %d",a,b,c);

See the docs here

Creating a Zoom Effect on an image on hover using CSS?

I like using a background image. I find it easier and more flexible:

DEMO

CSS:

#menu {
    max-width: 1200px;
    text-align: center;
    margin: auto;
}
.zoomimg {
    display: inline-block;
    width: 250px;
    height: 375px;
    padding: 0px 5px 0px 5px;
    background-size: 100% 100%;
    background-repeat: no-repeat;
    background-position: center center;
    transition: all .5s ease;
}
.zoomimg:hover {
    cursor: pointer;
    background-size: 150% 150%;
}
.blog {
    background-image: url(http://s18.postimg.org/il7hbk7i1/image.png);
}
.music {
    background-image: url(http://s18.postimg.org/4st2fxgqh/image.png);
}
.projects {
    background-image: url(http://s18.postimg.org/sxtrxn115/image.png);
}
.bio {
    background-image: url(http://s18.postimg.org/5xn4lb37d/image.png);
}

HTML:

<div id="menu">
    <div class="blog zoomimg"></div>
    <div class="music zoomimg"></div>
    <div class="projects zoomimg"></div>
    <div class="bio zoomimg"></div>
</div>

DEMO 2 with Overlay

What is the difference between __dirname and ./ in node.js?

The gist

In Node.js, __dirname is always the directory in which the currently executing script resides (see this). So if you typed __dirname into /d1/d2/myscript.js, the value would be /d1/d2.

By contrast, . gives you the directory from which you ran the node command in your terminal window (i.e. your working directory) when you use libraries like path and fs. Technically, it starts out as your working directory but can be changed using process.chdir().

The exception is when you use . with require(). The path inside require is always relative to the file containing the call to require.

For example...

Let's say your directory structure is

/dir1
  /dir2
    pathtest.js

and pathtest.js contains

var path = require("path");
console.log(". = %s", path.resolve("."));
console.log("__dirname = %s", path.resolve(__dirname));

and you do

cd /dir1/dir2
node pathtest.js

you get

. = /dir1/dir2
__dirname = /dir1/dir2

Your working directory is /dir1/dir2 so that's what . resolves to. Since pathtest.js is located in /dir1/dir2 that's what __dirname resolves to as well.

However, if you run the script from /dir1

cd /dir1
node dir2/pathtest.js

you get

. = /dir1
__dirname = /dir1/dir2

In that case, your working directory was /dir1 so that's what . resolved to, but __dirname still resolves to /dir1/dir2.

Using . inside require...

If inside dir2/pathtest.js you have a require call into include a file inside dir1 you would always do

require('../thefile')

because the path inside require is always relative to the file in which you are calling it. It has nothing to do with your working directory.

Font Awesome not working, icons showing as squares

In case you are working with Maven and Apache Wicket also check for the following in order to try to resolve the issue with Font-Awesome and icons not being loaded:

If you have placed your files for example in the following file structure

/src
 /main
  /java
   /your
    /package
     /css
      font-awesome.css
     /font
      fontawesome-webfont.eot
      fontawesome-webfont.svg
      fontawesome-webfont.svgz
      fontawesome-webfont.ttf
      fontawesome-webfont.woff

Check 1) Are you correctly using a Package Resource Guard in order to allow to load the font files correctly?

Example from your class which extends WebApplication:

@Override
public void init() {
    super.init();   
    get().getResourceSettings().setPackageResourceGuard(new PackageResourceGuard());

}

Check 2) After you have made sure that all fonts are correctly transferred to the Web Browser, check for what has been actually transferred to the Web Browser, i.e., did the integrity of the font files change? Compare the files in your source directory and the files transferred to the Web Browser using, e.g., the Web Developer Toolbar of Firefox and DiffDog (for file comparison).

In particular if you are using Maven be aware of resource filtering. Do not filter the folder where your /font files are contained - otherwise they will be corrupted.

Example from your pom.xml

<build>
    <finalName>Your project</finalName>
    <resources>
        <resource>
            <filtering>true</filtering>
            <directory>src/main/resources</directory>
        </resource>
        <resource>
            <filtering>false</filtering>
            <directory>src/main/java</directory>
            <includes>
                <include>**</include>
            </includes>
            <excludes>
                <exclude>**/*.java</exclude>
            </excludes>
        </resource>
    </resources>
</build>

In the example above we do not filter the folder src/main/java, where the css and font files are contained.

For further information on the filtering of binary data please also see the documentation:

http://maven.apache.org/plugins/maven-resources-plugin/examples/filter.html

In particular the documentation warns: "Warning: Do not filter files with binary content like images! This will most likely result in corrupt output. If you have both text files and binary files as resources, you need to declare two mutually exclusive resource sets. The first resource set defines the files to be filtered and the other resource set defines the files to copy unaltered..."

What is Linux’s native GUI API?

Wayland

As you might hear, wayland is the featured choice of many distros these days, because of its protocol is simpler than the X.

Toolkits of wayland

Toolkits or gui libraries that wayland suggests are:

  • QT 5
  • GTK+
  • LSD
  • Clutter
  • EFL

Find if a String is present in an array

This can be done in java 8 using Stream.

import java.util.stream.Stream;

String[] stringList = {"Red", "Orange", "Yellow", "Green", "Blue", "Violet", "Orange", "Blue"};

boolean contains = Stream.of(stringList).anyMatch(x -> x.equals(say.getText());

Replace text in HTML page with jQuery

var replaced = $("body").html().replace(/-1o9-2202/g,'The ALL new string');
$("body").html(replaced);

for variable:

var replaced = $("body").html().replace(new RegExp("-1o9-2202", "igm"),'The ALL new string');
$("body").html(replaced);

<code> vs <pre> vs <samp> for inline and block code snippets

For normal inlined <code> use:

<code>...</code>

and for each and every place where blocked <code> is needed use

<code style="display:block; white-space:pre-wrap">...</code>

Alternatively, define a <codenza> tag for break lining block <code> (no classes)

<script>
</script>
<style>
  codenza, code {}     /*  noop mnemonic aide that codenza mimes code tag  */
  codenza {display:block;white-space:pre-wrap}
</style>`

Testing: (NB: the following is a scURIple utilizing a data: URI protocol/scheme, therefore the %0A nl format codes are essential in preserving such when cut and pasted into the URL bar for testing - so view-source: (ctrl-U) looks good preceed every line below with %0A)

data:text/html;charset=utf-8,<html >
<script>document.write(window.navigator.userAgent)</script>
<script></script>
<style>
  codenza, code {}     /*  noop mnemonic aide that codenza mimes code tag  */
  codenza {display:block;white-space:pre-wrap}
</style>
<p>First using the usual &lt;code> tag
<code>
  %0A     function x(arghhh){ 
  %0A          return "a very long line of text that will extend the code beyond the boundaries of the margins, guaranteed for the most part, well maybe without you as a warrantee (except in abnormally conditioned perverse environs in which case a warranty is useless)"
  %0A     }
</code>
and then 
<p>with the tag blocked using pre-wrapped lines
<code style=display:block;white-space:pre-wrap> 
  %0A     function x(arghhh){ 
  %0A          return "a very long line of text that will extend the code beyond the boundaries of the margins, guaranteed for the most part, well maybe without you as a warrantee (except in abnormally conditioned perverse environs in which case a warranty is useless)"
  %0A     }
</code>
<br>using an ersatz tag
<codenza>
  %0A     function x(arghhh){ 
  %0A          return "a very long line of text that will extend the code beyond the boundaries of the margins, guaranteed for the most part, well maybe without you as a warrantee (except in abnormally conditioned perverse environs in which case a warranty is useless)"
 %0A     }
</codenza>
</html>

Change the "No file chosen":

<div class="field">
    <label class="field-label" for="photo">Your photo</label>
    <input class="field-input" type="file" name="photo"  id="photo" value="photo" />
</div>

and the css

input[type="file"]
{ 
   color: transparent; 
   background-color: #F89406; 
   border: 2px solid #34495e; 
   width: 100%; 
   height: 36px; 
   border-radius: 3px; 
}

How to compare two JSON have the same properties without order?

We use the node-deep-equal project which implements the same deep-equal comparison as nodejs

A google serach for deep-equal on npm will show you many alternatives

How do I set the background color of my main screen in Flutter?

I think you can also use a scaffold to do the white background. Here's some piece of code that may help.

import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
  @override
    Widget build(BuildContext context) {

      return new MaterialApp(
        title: 'Testing',
        home: new Scaffold(
        //Here you can set what ever background color you need.
          backgroundColor: Colors.white,
        ),
      );
    }
}

Hope this helps .

No Title Bar Android Theme

use android:theme="@android:style/Theme.NoTitleBar in manifest file's application tag to remove the title bar for whole application or put it in activity tag to remove the title bar from a single activity screen.

How to add a second css class with a conditional value in razor MVC 4

You can use String.Format function to add second class based on condition:

<div class="@String.Format("details {0}", Details.Count > 0 ? "show" : "hide")">

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

Use the static Double.isNaN(double) method, or your Double's .isNaN() method.

// 1. static method
if (Double.isNaN(doubleValue)) {
    ...
}
// 2. object's method
if (doubleObject.isNaN()) {
    ...
}

Simply doing:

if (var == Double.NaN) {
    ...
}

is not sufficient due to how the IEEE standard for NaN and floating point numbers is defined.

How do I write JSON data to a file?

json.dump(data, open('data.txt', 'wb'))

What does iterator->second mean?

I'm sure you know that a std::vector<X> stores a whole bunch of X objects, right? But if you have a std::map<X, Y>, what it actually stores is a whole bunch of std::pair<const X, Y>s. That's exactly what a map is - it pairs together the keys and the associated values.

When you iterate over a std::map, you're iterating over all of these std::pairs. When you dereference one of these iterators, you get a std::pair containing the key and its associated value.

std::map<std::string, int> m = /* fill it */;
auto it = m.begin();

Here, if you now do *it, you will get the the std::pair for the first element in the map.

Now the type std::pair gives you access to its elements through two members: first and second. So if you have a std::pair<X, Y> called p, p.first is an X object and p.second is a Y object.

So now you know that dereferencing a std::map iterator gives you a std::pair, you can then access its elements with first and second. For example, (*it).first will give you the key and (*it).second will give you the value. These are equivalent to it->first and it->second.

ListView with Add and Delete Buttons in each Row in android

You will first need to create a custom layout xml which will represent a single item in your list. You will add your two buttons to this layout along with any other items you want to display from your list.

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" > 

<TextView
    android:id="@+id/list_item_string"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:layout_alignParentLeft="true"
    android:paddingLeft="8dp"
    android:textSize="18sp"
    android:textStyle="bold" /> 

<Button
    android:id="@+id/delete_btn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_centerVertical="true"
    android:layout_marginRight="5dp"
    android:text="Delete" /> 

<Button
    android:id="@+id/add_btn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_toLeftOf="@id/delete_btn"
    android:layout_centerVertical="true"
    android:layout_marginRight="10dp"
    android:text="Add" />

</RelativeLayout>

Next you will need to create a Custom ArrayAdapter Class which you will use to inflate your xml layout, as well as handle your buttons and on click events.

public class MyCustomAdapter extends BaseAdapter implements ListAdapter { 
private ArrayList<String> list = new ArrayList<String>(); 
private Context context; 



public MyCustomAdapter(ArrayList<String> list, Context context) { 
    this.list = list; 
    this.context = context; 
} 

@Override
public int getCount() { 
    return list.size(); 
} 

@Override
public Object getItem(int pos) { 
    return list.get(pos); 
} 

@Override
public long getItemId(int pos) { 
    return list.get(pos).getId();
    //just return 0 if your list items do not have an Id variable.
} 

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    View view = convertView;
    if (view == null) {
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
        view = inflater.inflate(R.layout.my_custom_list_layout, null);
    } 

    //Handle TextView and display string from your list
    TextView listItemText = (TextView)view.findViewById(R.id.list_item_string); 
    listItemText.setText(list.get(position)); 

    //Handle buttons and add onClickListeners
    Button deleteBtn = (Button)view.findViewById(R.id.delete_btn);
    Button addBtn = (Button)view.findViewById(R.id.add_btn);

    deleteBtn.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) { 
            //do something
            list.remove(position); //or some other task
            notifyDataSetChanged();
        }
    });
    addBtn.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) { 
            //do something
            notifyDataSetChanged();
        }
    });

    return view; 
} 
}

Finally, in your activity you can instantiate your custom ArrayAdapter class and set it to your listview.

public class MyActivity extends Activity { 

@Override
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_my_activity); 

    //generate list
    ArrayList<String> list = new ArrayList<String>();
    list.add("item1");
    list.add("item2");

    //instantiate custom adapter
    MyCustomAdapter adapter = new MyCustomAdapter(list, this);

    //handle listview and assign adapter
    ListView lView = (ListView)findViewById(R.id.my_listview);
    lView.setAdapter(adapter);
}

Hope this helps!

Port 80 is being used by SYSTEM (PID 4), what is that?

I just got this problem today, since it showed up after Norton requested reboot I blamed Norton.
But it wasn't Norton, I removed Norton, rebooted -> problem still there.

netstat -nao was showing that PID 4 owned my port 80 connection.

I then went to control panel, then "Turn Windows features on or off" then unchecked Internet Information Services.
Rebooted, the problem went away.
My xampp server is running ok now.

I don't ever remembering turning IIS on in the first place. I had been running many months before this happened. I still don't know what caused it in the first place. Maybe a previous windows updated enabled iis and my reboot turned it on, I don't know.

References with text in LaTeX

Have a look to this wiki: LaTeX/Labels and Cross-referencing:

The hyperref package automatically includes the nameref package, and a similarly named command. It inserts text corresponding to the section name, for example:

\section{MyFirstSection}
\label{marker}
\section{MySecondSection} In section \nameref{marker} we defined...

How to access the local Django webserver from outside world

I'm going to add this here:

  1. sudo python manage.py runserver 80

  2. Go to your phone or computer and enter your computers internal IP (e.g 192.168.0.12) into the browser.

At this point you should be connected to the Django server.

This should also work without sudo:

python manage.py runserver 0.0.0.0:8000

Why am I getting a "401 Unauthorized" error in Maven?

just change in settings.xml these as aliteralmind says:

  <server>
      <id>nexus-snapshots</id>
      <username>MY_SONATYPE_DOT_COM_USERNAME</username>
      <password>MY_SONATYPE_DOT_COM_PASSWORD</password>    
 </server>

you probably need to get the username / password from sonatype dot com.

ToList().ForEach in Linq

employees.ToList().ForEach(
     emp=>
     {
          collection.AddRange(emp.Departments);
          emp.Departments.ToList().ForEach(u=>u.SomeProperty = null);
     });

How do I expire a PHP session after 30 minutes?

Please use following block of code in your include file which loaded in every pages.

$expiry = 1800 ;//session expiry required after 30 mins
    if (isset($_SESSION['LAST']) && (time() - $_SESSION['LAST'] > $expiry)) {
        session_unset();
        session_destroy();
    }
    $_SESSION['LAST'] = time();

How to extract code of .apk file which is not working?

step 1:

enter image description hereDownload dex2jar here. Create a java project and paste (dex2jar-0.0.7.11-SNAPSHOT/lib ) jar files .

Copy apk file into java project

Run it and after refresh the project ,you get jar file .Using java decompiler you can view all java class files

step 2: Download java decompiler here

Calling a Sub and returning a value

Private Sub Main()
    Dim value = getValue()
    'do something with value
End Sub

Private Function getValue() As Integer
    Return 3
End Function

Make a DIV fill an entire table cell

I ultimately found nothing that would work across all my browsers and all DocTypes / browser rendering modes, except for using jQuery. So here is what I came up with.
It even takes rowspan into account.

function InitDivHeights() {
    var spacing = 10; // <-- Tune this value to match your tr/td spacing and padding.
    var rows = $('#MyTable tr');
    var heights = [];
    for (var i = 0; i < rows.length; i++)
        heights[i] = $(rows[i]).height();
    for (var i = 0; i < rows.length; i++) {
        var row = $(rows[i]);
        var cells = $('td', row);
        for (var j = 0; j < cells.length; j++) {
            var cell = $(cells[j]);
            var rowspan = cell.attr('rowspan') || 1;
            var newHeight = 0;
            for (var k = 0; (k < rowspan && i + k < heights.length); k++)
                newHeight += heights[i + k];
            $('div', cell).height(newHeight - spacing);
        }
    }
}
$(document).ready(InitDivHeights);

Tested in IE11 (Edge mode), FF42, Chrome44+. Not tested with nested tables.

Angular CLI - Please add a @NgModule annotation when using latest

In my case, I created a new ChildComponent in Parentcomponent whereas both in the same module but Parent is registered in a shared module so I created ChildComponent using CLI which registered Child in the current module but my parent was registered in the shared module.

So register the ChildComponent in Shared Module manually.

How to generate a random integer number from within a range

Will return a floating point number in the range [0,1]:

#define rand01() (((double)random())/((double)(RAND_MAX)))

Http Basic Authentication in Java using HttpClient?

while using Header array

String auth = Base64.getEncoder().encodeToString(("test1:test1").getBytes());
Header[] headers = {
    new BasicHeader(HTTP.CONTENT_TYPE, ContentType.APPLICATION_JSON.toString()),
    new BasicHeader("Authorization", "Basic " +auth)
};

Can not change UILabel text color

May be the better way is

UIColor *color = [UIColor greenColor];
[self.myLabel setTextColor:color];

Thus we have colored text

How to trigger event in JavaScript?

if you use jQuery, you can simple do

$('#yourElement').trigger('customEventName', [arg0, arg1, ..., argN]);

and handle it with

$('#yourElement').on('customEventName',
   function (objectEvent, [arg0, arg1, ..., argN]){
       alert ("customEventName");
});

where "[arg0, arg1, ..., argN]" means that these args are optional.

Export MySQL data to Excel in PHP

Try the Following Code Please. just only update two values.
1.your_database_name 2.table_name

 <?php
    $host="localhost";
    $username="root";
    $password="";
    $dbname="your_database_name";
    $con = new mysqli($host, $username, $password,$dbname); 

        $sql_data="select * from table_name";
        $result_data=$con->query($sql_data);
        $results=array();
    filename = "Webinfopen.xls"; // File Name
    // Download file
    header("Content-Disposition: attachment; filename=\"$filename\"");
    header("Content-Type: application/vnd.ms-excel");

    $flag = false;
    while ($row = mysqli_fetch_assoc($result_data)) {
        if (!$flag) {
            // display field/column names as first row
            echo implode("\t", array_keys($row)) . "\r\n";
            $flag = true;
        }
        echo implode("\t", array_values($row)) . "\r\n";
    }
    ?>

max value of integer

The poster has their java types mixed up. in java, his C in is a short: short (16 bit) = -32768 to 32767 int (32 bit) = -2,147,483,648 to 2,147,483,647

http://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html

CSS change button style after click

What is the code of your button? If it's an a tag, then you could do this:

_x000D_
_x000D_
a {_x000D_
  padding: 5px;_x000D_
  background: green;_x000D_
}_x000D_
a:visited {_x000D_
  background: red;_x000D_
}
_x000D_
<a href="#">A button</a>
_x000D_
_x000D_
_x000D_

Or you could use jQuery to add a class on click, as below:

_x000D_
_x000D_
$("#button").click(function() {_x000D_
  $("#button").addClass('button-clicked');_x000D_
});
_x000D_
.button-clicked {_x000D_
  background: red;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<button id="button">Button</button>
_x000D_
_x000D_
_x000D_

Determine if $.ajax error is a timeout

If your error event handler takes the three arguments (xmlhttprequest, textstatus, and message) when a timeout happens, the status arg will be 'timeout'.

Per the jQuery documentation:

Possible values for the second argument (besides null) are "timeout", "error", "notmodified" and "parsererror".

You can handle your error accordingly then.

I created this fiddle that demonstrates this.

$.ajax({
    url: "/ajax_json_echo/",
    type: "GET",
    dataType: "json",
    timeout: 1000,
    success: function(response) { alert(response); },
    error: function(xmlhttprequest, textstatus, message) {
        if(textstatus==="timeout") {
            alert("got timeout");
        } else {
            alert(textstatus);
        }
    }
});?

With jsFiddle, you can test ajax calls -- it will wait 2 seconds before responding. I put the timeout setting at 1 second, so it should error out and pass back a textstatus of 'timeout' to the error handler.

Hope this helps!

Filtering DataSet

The above were really close. Here's my solution:

Private Sub getDsClone(ByRef inClone As DataSet, ByVal matchStr As String, ByRef outClone As DataSet)
    Dim i As Integer

    outClone = inClone.Clone
    Dim dv As DataView = inClone.Tables(0).DefaultView
    dv.RowFilter = matchStr
    Dim dt As New DataTable
    dt = dv.ToTable
    For i = 0 To dv.Count - 1
        outClone.Tables(0).ImportRow(dv.Item(i).Row)
    Next
End Sub

How to declare string constants in JavaScript?

Use global namespace or global object like Constants.

var Constants = {};

And using defineObject write function which will add all properties to that object and assign value to it.

function createConstant (prop, value) {
    Object.defineProperty(Constants , prop, {
      value: value,
      writable: false
   });
};

Upgrade version of Pandas

Simple Solution, just type the below:

conda update pandas 

Type this in your preferred shell (on Windows, use Anaconda Prompt as administrator).

Vim clear last search highlighting

To turn off highlighting until the next search:

:noh

Or turn off highlighting completely:

set nohlsearch

Or, to toggle it:

set hlsearch!

nnoremap <F3> :set hlsearch!<CR>

Warning about `$HTTP_RAW_POST_DATA` being deprecated

If the .htaccess file not avilable create it on root folder and past this line of code.

Put this in .htaccess file (tested working well for API)

<IfModule mod_php5.c>
    php_value always_populate_raw_post_data -1
</IfModule>

Best way to move files between S3 buckets?

The new official AWS CLI natively supports most of the functionality of s3cmd. I'd previously been using s3cmd or the ruby AWS SDK to do things like this, but the official CLI works great for this.

http://docs.aws.amazon.com/cli/latest/reference/s3/sync.html

aws s3 sync s3://oldbucket s3://newbucket

How to add empty spaces into MD markdown readme on GitHub?

I'm surprised no one mentioned the HTML entities &ensp; and &emsp; which produce horizontal white space equivalent to the characters n and m, respectively. If you want to accumulate horizontal white space quickly, those are more efficient than &nbsp;.

  1. no space
  2.  &nbsp;
  3. &ensp;
  4. &emsp;

Along with <space> and &thinsp;, these are the five entities HTML provides for horizontal white space.

Note that except for &nbsp;, all entities allow breaking. Whatever text surrounds them will wrap to a new line if it would otherwise extend beyond the container boundary. With &nbsp; it would wrap to a new line as a block even if the text before &nbsp; could fit on the previous line.

Depending on your use case, that may be desired or undesired. For me, unless I'm dealing with things like names (John&nbsp;Doe), addresses or references (see eq.&nbsp;5), breaking as a block is usually undesired.

Change icon-bar (?) color in bootstrap

I do not know if your still looking for the answer to this problem but today I happened the same problem and solved it. You need to specify in the HTML code,

**<Div class = "navbar"**>
         div class = "container">
               <Div class = "navbar-header">

or

**<Div class = "navbar navbar-default">**
        div class = "container">
               <Div class = "navbar-header">

You got that place in your CSS

.navbar-default-toggle .navbar .icon-bar {
  background-color: # 0000ff;
}

and what I did was add above

.navbar .navbar-toggle .icon-bar {
  background-color: # ff0000;
}

Because my html code is

**<Div class = "navbar">**
         div class = "container">
               <Div class = "navbar-header">

and if you associate a file less / css

search this section and also here placed the color you want to change, otherwise it will self-correct the css file to the state it was before

// Toggle Navbar
@ Navbar-default-toggle-hover-bg: #ddd;
**@ Navbar-default-toggle-icon-bar-bg: # 888;**
@ Navbar-default-toggle-border-color: #ddd;

if your html code is like mine and is not navbar-default, add it as you did with the css.

// Toggle Navbar
@ Navbar-default-toggle-hover-bg: #ddd;
**@ Navbar-toggle-icon-bar-bg : #888;**
@ Navbar-default-toggle-icon-bar-bg: # 888;
@ Navbar-default-toggle-border-color: #ddd;

good luck

pip connection failure: cannot fetch index base URL http://pypi.python.org/simple/

You can try with this below command:

python -m pip install --trusted-host https://pypi.python.org deepdiff

it will work.

Two inline-block, width 50% elements wrap to second line

inline and inline-block elements are affected by whitespace in the HTML.

The simplest way to fix your problem is to remove the whitespace between </div> and <div id="col2">, see: http://jsfiddle.net/XCDsu/15/

There are other possible solutions, see: bikeshedding CSS3 property alternative?

Find all files in a directory with extension .txt in Python

A simple method by using for loop :

import os

dir = ["e","x","e"]

p = os.listdir('E:')  #path

for n in range(len(p)):
   name = p[n]
   myfile = [name[-3],name[-2],name[-1]]  #for .txt
   if myfile == dir :
      print(name)
   else:
      print("nops")

Though this can be made more generalised .

How do I resolve "Run-time error '429': ActiveX component can't create object"?

The file msrdo20.dll is missing from the installation.

According to the Support Statement for Visual Basic 6.0 on Windows Vista, Windows Server 2008 and Windows 7 this file should be distributed with the application.

I'm not sure why it isn't, but my solution is to place the file somewhere on the machine, and register it using regsvr32 in the command line, eg:

regsvr32 c:\windows\system32\msrdo20.dll

In an ideal world you would package this up with the redistributable.

How to convert a Map to List in Java?

Here's the generic method to get values from map.

public static <T> List<T> ValueListFromMap(HashMap<String, T> map) {
    List<T> thingList = new ArrayList<>();

    for (Map.Entry<String, T> entry : map.entrySet()) {
        thingList.add(entry.getValue());
    }

    return thingList;
}

How to check the version before installing a package using apt-get?

Linux Mint, Debian 9, Ubuntu 16.04 and older:

Short info:

apt policy <package_name>

Detailed info (With Description and Depends):

apt show <package_name>

How do I create dynamic properties in C#?

If you need this for data-binding purposes, you can do this with a custom descriptor model... by implementing ICustomTypeDescriptor, TypeDescriptionProvider and/or TypeCoverter, you can create your own PropertyDescriptor instances at runtime. This is what controls like DataGridView, PropertyGrid etc use to display properties.

To bind to lists, you'd need ITypedList and IList; for basic sorting: IBindingList; for filtering and advanced sorting: IBindingListView; for full "new row" support (DataGridView): ICancelAddNew (phew!).

It is a lot of work though. DataTable (although I hate it) is cheap way of doing the same thing. If you don't need data-binding, just use a hashtable ;-p

Here's a simple example - but you can do a lot more...

Format LocalDateTime with Timezone in Java8

The prefix "Local" in JSR-310 (aka java.time-package in Java-8) does not indicate that there is a timezone information in internal state of that class (here: LocalDateTime). Despite the often misleading name such classes like LocalDateTime or LocalTime have NO timezone information or offset.

You tried to format such a temporal type (which does not contain any offset) with offset information (indicated by pattern symbol Z). So the formatter tries to access an unavailable information and has to throw the exception you observed.

Solution:

Use a type which has such an offset or timezone information. In JSR-310 this is either OffsetDateTime (which contains an offset but not a timezone including DST-rules) or ZonedDateTime. You can watch out all supported fields of such a type by look-up on the method isSupported(TemporalField).. The field OffsetSeconds is supported in OffsetDateTime and ZonedDateTime, but not in LocalDateTime.

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd HH:mm:ss.SSSSSS Z");
String s = ZonedDateTime.now().format(formatter);

How to import RecyclerView for Android L-preview

implementation 'com.android.support:appcompat-v7:28.0.0'

implementation 'com.android.support:recyclerview-v7:28.0.0'

Above works for me in build.gradle file

Object comparison in JavaScript

Here is my ES3 commented solution (gory details after the code):

function object_equals( x, y ) {
  if ( x === y ) return true;
    // if both x and y are null or undefined and exactly the same

  if ( ! ( x instanceof Object ) || ! ( y instanceof Object ) ) return false;
    // if they are not strictly equal, they both need to be Objects

  if ( x.constructor !== y.constructor ) return false;
    // they must have the exact same prototype chain, the closest we can do is
    // test there constructor.

  for ( var p in x ) {
    if ( ! x.hasOwnProperty( p ) ) continue;
      // other properties were tested using x.constructor === y.constructor

    if ( ! y.hasOwnProperty( p ) ) return false;
      // allows to compare x[ p ] and y[ p ] when set to undefined

    if ( x[ p ] === y[ p ] ) continue;
      // if they have the same strict value or identity then they are equal

    if ( typeof( x[ p ] ) !== "object" ) return false;
      // Numbers, Strings, Functions, Booleans must be strictly equal

    if ( ! object_equals( x[ p ],  y[ p ] ) ) return false;
      // Objects and Arrays must be tested recursively
  }

  for ( p in y )
    if ( y.hasOwnProperty( p ) && ! x.hasOwnProperty( p ) )
      return false;
        // allows x[ p ] to be set to undefined

  return true;
}

In developing this solution, I took a particular look at corner cases, efficiency, yet trying to yield a simple solution that works, hopefully with some elegance. JavaScript allows both null and undefined properties and objects have prototypes chains that can lead to very different behaviors if not checked.

First I have chosen to not extend Object.prototype, mostly because null could not be one of the objects of the comparison and that I believe that null should be a valid object to compare with another. There are also other legitimate concerns noted by others regarding the extension of Object.prototype regarding possible side effects on other's code.

Special care must taken to deal the possibility that JavaScript allows object properties can be set to undefined, i.e. there exists properties which values are set to undefined. The above solution verifies that both objects have the same properties set to undefined to report equality. This can only be accomplished by checking the existence of properties using Object.hasOwnProperty( property_name ). Also note that JSON.stringify() removes properties that are set to undefined, and that therefore comparisons using this form will ignore properties set to the value undefined.

Functions should be considered equal only if they share the same reference, not just the same code, because this would not take into account these functions prototype. So comparing the code string does not work to guaranty that they have the same prototype object.

The two objects should have the same prototype chain, not just the same properties. This can only be tested cross-browser by comparing the constructor of both objects for strict equality. ECMAScript 5 would allow to test their actual prototype using Object.getPrototypeOf(). Some web browsers also offer a __proto__ property that does the same thing. A possible improvement of the above code would allow to use one of these methods whenever available.

The use of strict comparisons is paramount here because 2 should not be considered equal to "2.0000", nor false should be considered equal to null, undefined, or 0.

Efficiency considerations lead me to compare for equality of properties as soon as possible. Then, only if that failed, look for the typeof these properties. The speed boost could be significant on large objects with lots of scalar properties.

No more that two loops are required, the first to check properties from the left object, the second to check properties from the right and verify only existence (not value), to catch these properties which are defined with the undefined value.

Overall this code handles most corner cases in only 16 lines of code (without comments).


Update (8/13/2015). I have implemented a better version, as the function value_equals() that is faster, handles properly corner cases such as NaN and 0 different than -0, optionally enforcing objects' properties order and testing for cyclic references, backed by more than 100 automated tests as part of the Toubkal project test suite.

Html.EditorFor Set Default Value

This worked for me

In Controlle

 ViewBag.AAA = default_Value ;

In View

@Html.EditorFor(model => model.AAA, new { htmlAttributes = new { @Value = ViewBag.AAA } }

What tool to use to draw file tree diagram

As promised, here is my Cairo version. I scripted it with Lua, using lfs to walk the directories. I love these little challenges, as they allow me to explore APIs I wanted to dig for quite some time...
lfs and LuaCairo are both cross-platform, so it should work on other systems (tested on French WinXP Pro SP3).

I made a first version drawing file names as I walked the tree. Advantage: no memory overhead. Inconvenience: I have to specify the image size beforehand, so listings are likely to be cut off.

So I made this version, first walking the directory tree, storing it in a Lua table. Then, knowing the number of files, creating the canvas to fit (at least vertically) and drawing the names.
You can easily switch between PNG rendering and SVG one. Problem with the latter: Cairo generates it at low level, drawing the letters instead of using SVG's text capability. Well, at least, it guarantees accurate rending even on systems without the font. But the files are bigger... Not really a problem if you compress it after, to have a .svgz file.
Or it shouldn't be too hard to generate the SVG directly, I used Lua to generate SVG in the past.

-- LuaFileSystem <http://www.keplerproject.org/luafilesystem/>
require"lfs"
-- LuaCairo <http://www.dynaset.org/dogusanh/>
require"lcairo"
local CAIRO = cairo


local PI = math.pi
local TWO_PI = 2 * PI

--~ local dirToList = arg[1] or "C:/PrgCmdLine/Graphviz"
--~ local dirToList = arg[1] or "C:/PrgCmdLine/Tecgraf"
local dirToList = arg[1] or "C:/PrgCmdLine/tcc"
-- Ensure path ends with /
dirToList = string.gsub(dirToList, "([^/])$", "%1/")
print("Listing: " .. dirToList)
local fileNb = 0

--~ outputType = 'svg'
outputType = 'png'

-- dirToList must have a trailing slash
function ListDirectory(dirToList)
  local dirListing = {}
  for file in lfs.dir(dirToList) do
    if file ~= ".." and file ~= "." then
      local fileAttr = lfs.attributes(dirToList .. file)
      if fileAttr.mode == "directory" then
        dirListing[file] = ListDirectory(dirToList .. file .. '/')
      else
        dirListing[file] = ""
      end
      fileNb = fileNb + 1
    end
  end
  return dirListing
end

--dofile[[../Lua/DumpObject.lua]] -- My own dump routine
local dirListing = ListDirectory(dirToList)
--~ print("\n" .. DumpObject(dirListing))
print("Found " .. fileNb .. " files")

--~ os.exit()

-- Constants to change to adjust aspect
local initialOffsetX = 20
local offsetY = 50
local offsetIncrementX = 20
local offsetIncrementY = 12
local iconOffset = 10

local width = 800 -- Still arbitrary
local titleHeight = width/50
local height = offsetIncrementY * (fileNb + 1) + titleHeight
local outfile = "CairoDirTree." .. outputType

local ctxSurface
if outputType == 'svg' then
  ctxSurface = cairo.SvgSurface(outfile, width, height)
else
  ctxSurface = cairo.ImageSurface(CAIRO.FORMAT_RGB24, width, height)
end
local ctx = cairo.Context(ctxSurface)

-- Display a file name
-- file is the file name to display
-- offsetX is the indentation
function DisplayFile(file, bIsDir, offsetX)
  if bIsDir then
    ctx:save()
    ctx:select_font_face("Sans", CAIRO.FONT_SLANT_NORMAL, CAIRO.FONT_WEIGHT_BOLD)
    ctx:set_source_rgb(0.5, 0.0, 0.7)
  end

  -- Display file name
  ctx:move_to(offsetX, offsetY)
  ctx:show_text(file)

  if bIsDir then
    ctx:new_sub_path() -- Position independent of latest move_to
    -- Draw arc with absolute coordinates
    ctx:arc(offsetX - iconOffset, offsetY - offsetIncrementY/3, offsetIncrementY/3, 0, TWO_PI)
    -- Violet disk
    ctx:set_source_rgb(0.7, 0.0, 0.7)
    ctx:fill()
    ctx:restore() -- Restore original settings
  end

  -- Increment line offset
  offsetY = offsetY + offsetIncrementY
end

-- Erase background (white)
ctx:set_source_rgb(1.0, 1.0, 1.0)
ctx:paint()

--~ ctx:set_line_width(0.01)

-- Draw in dark blue
ctx:set_source_rgb(0.0, 0.0, 0.3)
ctx:select_font_face("Sans", CAIRO.FONT_SLANT_NORMAL, CAIRO.FONT_WEIGHT_BOLD)
ctx:set_font_size(titleHeight)
ctx:move_to(5, titleHeight)
-- Display title
ctx:show_text("Directory tree of " .. dirToList)

-- Select font for file names
ctx:select_font_face("Sans", CAIRO.FONT_SLANT_NORMAL, CAIRO.FONT_WEIGHT_NORMAL)
ctx:set_font_size(10)
offsetY = titleHeight * 2

-- Do the job
function DisplayDirectory(dirToList, offsetX)
  for k, v in pairs(dirToList) do
--~ print(k, v)
    if type(v) == "table" then
      -- Sub-directory
      DisplayFile(k, true, offsetX)
      DisplayDirectory(v, offsetX + offsetIncrementX)
    else
      DisplayFile(k, false, offsetX)
    end
  end
end

DisplayDirectory(dirListing, initialOffsetX)

if outputType == 'svg' then
    cairo.show_page(ctx)
else
  --cairo.surface_write_to_png(ctxSurface, outfile)
  ctxSurface:write_to_png(outfile)
end

ctx:destroy()
ctxSurface:destroy()

print("Found " .. fileNb .. " files")

Of course, you can change the styles. I didn't draw the connection lines, I didn't saw it as necessary. I might add them optionally later.

`node-pre-gyp install --fallback-to-build` failed during MeanJS installation on OSX

I recently had this error on a fresh OSX install of Node using homebrew. Brew installed the latest at the time 13.8.0.

I downgraded the last "stable" release of node.

sudo npm install -g n  ## Installs Node Version Switcher
sudo n stable          ## To switch to latest stable version

Then the rest of my npm installs finished and passed the dreaded gprc errors!

Extracting text from HTML file using Python

The LibreOffice writer comment has merit since the application can employ python macros. It seems to offer multiple benefits both for answering this question and furthering the macro base of LibreOffice. If this resolution is a one-off implementation, rather than to be used as part of a greater production program, opening the HTML in writer and saving the page as text would seem to resolve the issues discussed here.

How do you use bcrypt for hashing passwords in PHP?

You can create a one-way hash with bcrypt using PHP's crypt() function and passing in an appropriate Blowfish salt. The most important of the whole equation is that A) the algorithm hasn't been compromised and B) you properly salt each password. Don't use an application-wide salt; that opens up your entire application to attack from a single set of Rainbow tables.

PHP - Crypt Function

How to convert datetime to timestamp using C#/.NET (ignoring current timezone)

Find timestamp from DateTime:

private long ConvertToTimestamp(DateTime value)
{
    TimeZoneInfo NYTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
    DateTime NyTime = TimeZoneInfo.ConvertTime(value, NYTimeZone);
    TimeZone localZone = TimeZone.CurrentTimeZone;
    System.Globalization.DaylightTime dst = localZone.GetDaylightChanges(NyTime.Year);
    NyTime = NyTime.AddHours(-1);
    DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0).ToLocalTime();
    TimeSpan span = (NyTime - epoch);
    return (long)Convert.ToDouble(span.TotalSeconds);
}

Open link in new tab or window

set the target attribute of your <a> element to "_tab"

EDIT: It works, however W3Schools says there is no such target attribute: http://www.w3schools.com/tags/att_a_target.asp

EDIT2: From what I've figured out from the comments. setting target to _blank will take you to a new tab or window (depending on your browser settings). Typing anything except one of the ones below will create a new tab group (I'm not sure how these work):

_blank  Opens the linked document in a new window or tab
_self   Opens the linked document in the same frame as it was clicked (this is default)
_parent Opens the linked document in the parent frame
_top    Opens the linked document in the full body of the window
framename   Opens the linked document in a named frame

GridView - Show headers on empty data source

I was just working through this problem, and none of these solutions would work for me. I couldn't use the EmptyDataTemplate property because I was creating my GridView dynamically with custom fields which provide filters in the headers. I couldn't use the example almny posted because I'm using ObjectDataSources instead of DataSet or DataTable. However, I found this answer posted on another StackOverflow question, which links to this elegant solution that I was able to make work for my particular situation. It involves overriding the CreateChildControls method of the GridView to create the same header row that would have been created had there been real data. I thought it worth posting here, where it's likely to be found by other people in a similar fix.

How to check compiler log in sql developer?

To see your log in SQL Developer then press:

CTRL+SHIFT + L (or CTRL + CMD + L on macOS)

or

View -> Log

or by using mysql query

show errors;

How to loop in excel without VBA or macros?

You could create a table somewhere on a calculation spreadsheet which performs this operation for each pair of cells, and use auto-fill to fill it up.

Aggregate the results from that table into a results cell.

The 200 so cells which reference the results could then reference the cell that holds the aggregation results. In the newest versions of excel you can name the result cell and reference it that way, for ease of reading.

How do I set session timeout of greater than 30 minutes

this will set your session to keep everything till the browser is closed

session.setMaxinactiveinterval(-1);

and this should set it for 1 day

session.setMaxInactiveInterval(60*60*24);

Cross-browser bookmark/add to favorites JavaScript

jQuery Version

JavaScript (modified from a script I found on someone's site - I just can't find the site again, so I can't give the person credit):

$(document).ready(function() {
  $("#bookmarkme").click(function() {
    if (window.sidebar) { // Mozilla Firefox Bookmark
      window.sidebar.addPanel(location.href,document.title,"");
    } else if(window.external) { // IE Favorite
      window.external.AddFavorite(location.href,document.title); }
    else if(window.opera && window.print) { // Opera Hotlist
      this.title=document.title;
      return true;
    }
  });
});

HTML:

<a id="bookmarkme" href="#" rel="sidebar" title="bookmark this page">Bookmark This Page</a>

IE will show an error if you don't run it off a server (it doesn't allow JavaScript bookmarks via JavaScript when viewing it as a file://...).

Flask SQLAlchemy query, specify column names

You can use the with_entities() method to restrict which columns you'd like to return in the result. (documentation)

result = SomeModel.query.with_entities(SomeModel.col1, SomeModel.col2)

Depending on your requirements, you may also find deferreds useful. They allow you to return the full object but restrict the columns that come over the wire.

How can I set the aspect ratio in matplotlib?

Third times the charm. My guess is that this is a bug and Zhenya's answer suggests it's fixed in the latest version. I have version 0.99.1.1 and I've created the following solution:

import matplotlib.pyplot as plt
import numpy as np

def forceAspect(ax,aspect=1):
    im = ax.get_images()
    extent =  im[0].get_extent()
    ax.set_aspect(abs((extent[1]-extent[0])/(extent[3]-extent[2]))/aspect)

data = np.random.rand(10,20)

fig = plt.figure()
ax = fig.add_subplot(111)
ax.imshow(data)
ax.set_xlabel('xlabel')
ax.set_aspect(2)
fig.savefig('equal.png')
ax.set_aspect('auto')
fig.savefig('auto.png')
forceAspect(ax,aspect=1)
fig.savefig('force.png')

This is 'force.png': enter image description here

Below are my unsuccessful, yet hopefully informative attempts.

Second Answer:

My 'original answer' below is overkill, as it does something similar to axes.set_aspect(). I think you want to use axes.set_aspect('auto'). I don't understand why this is the case, but it produces a square image plot for me, for example this script:

import matplotlib.pyplot as plt
import numpy as np

data = np.random.rand(10,20)

fig = plt.figure()
ax = fig.add_subplot(111)
ax.imshow(data)
ax.set_aspect('equal')
fig.savefig('equal.png')
ax.set_aspect('auto')
fig.savefig('auto.png')

Produces an image plot with 'equal' aspect ratio: enter image description here and one with 'auto' aspect ratio: enter image description here

The code provided below in the 'original answer' provides a starting off point for an explicitly controlled aspect ratio, but it seems to be ignored once an imshow is called.

Original Answer:

Here's an example of a routine that will adjust the subplot parameters so that you get the desired aspect ratio:

import matplotlib.pyplot as plt

def adjustFigAspect(fig,aspect=1):
    '''
    Adjust the subplot parameters so that the figure has the correct
    aspect ratio.
    '''
    xsize,ysize = fig.get_size_inches()
    minsize = min(xsize,ysize)
    xlim = .4*minsize/xsize
    ylim = .4*minsize/ysize
    if aspect < 1:
        xlim *= aspect
    else:
        ylim /= aspect
    fig.subplots_adjust(left=.5-xlim,
                        right=.5+xlim,
                        bottom=.5-ylim,
                        top=.5+ylim)

fig = plt.figure()
adjustFigAspect(fig,aspect=.5)
ax = fig.add_subplot(111)
ax.plot(range(10),range(10))

fig.savefig('axAspect.png')

This produces a figure like so: enter image description here

I can imagine if your having multiple subplots within the figure, you would want to include the number of y and x subplots as keyword parameters (defaulting to 1 each) to the routine provided. Then using those numbers and the hspace and wspace keywords, you can make all the subplots have the correct aspect ratio.

How to pass variables from one php page to another without form?

If you are trying to access the variable from another PHP file directly, you can include that file with include() or include_once(), giving you access to that variable. Note that this will include the entire first file in the second file.

Android Studio with Google Play Services

I've got this working after doing the following:

  • Have the google-play-services-lib as a module (note difference between module and project), then add the google-play-services.jar to your models "libs" directory.
  • After that add the jar to your build path through making a library or add the jar to another library. I generally have a single IDEA library which I add all my /libs/*.jar files to.
  • Add the library to your modules build path through Module Settings (F4).
  • Add the google-play-services-lib as a module dependency to your project.
  • Done!

Note: This doesn't give me the runtime exceptions either, it works.

Python Iterate Dictionary by Index

I wanted to know (idx, key, value) for a python OrderedDict today (mapping of SKUs to quantities in order of the way they should appear on a receipt). The answers here were all bummers.

In python 3, at least, this way works and and makes sense.

In [1]: from collections import OrderedDict
   ...: od = OrderedDict()
   ...: od['a']='spam'
   ...: od['b']='ham'
   ...: od['c']='eggs'
   ...: 
   ...: for i,(k,v) in enumerate(od.items()):
   ...:    print('%d,%s,%s'%(i,k,v))
   ...: 
0,a,spam
1,b,ham
2,c,eggs

Convert Base64 string to an image file?

An easy way I'm using:

file_put_contents($output_file, file_get_contents($base64_string));

This works well because file_get_contents can read data from a URI, including a data:// URI.

How to name variables on the fly?

Another tricky solution is to name elements of list and attach it:

list_name = list(
    head(iris),
    head(swiss),
    head(airquality)
    )

names(list_name) <- paste("orca", seq_along(list_name), sep="")
attach(list_name)

orca1
#   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
# 1          5.1         3.5          1.4         0.2  setosa
# 2          4.9         3.0          1.4         0.2  setosa
# 3          4.7         3.2          1.3         0.2  setosa
# 4          4.6         3.1          1.5         0.2  setosa
# 5          5.0         3.6          1.4         0.2  setosa
# 6          5.4         3.9          1.7         0.4  setosa

MySQL select all rows from last month until (now() - 1 month), for comparative purposes

You can get the first of the month, by calculating the last_day of the month before and add one day. It is awkward, but I think it is better than formatting a date as string and use that for calculation.

select 
  *
from
  yourtable t
where
  /* Greater or equal to the start of last month */
  t.date >= DATE_ADD(LAST_DAY(DATE_SUB(NOW(), INTERVAL 2 MONTH)), INTERVAL 1 DAY) and
  /* Smaller or equal than one month ago */
  t.date <= DATE_SUB(NOW(), INTERVAL 1 MONTH)

Best way to convert pdf files to tiff files

Use Imagemagick, or better yet, Ghostscript.

http://www.ibm.com/developerworks/library/l-graf2/#N101C2 has an example for imagemagick:

convert foo.pdf pages-%03d.tiff

http://www.asmail.be/msg0055376363.html has an example for ghostscript:

gs -q -dNOPAUSE -sDEVICE=tiffg4 -sOutputFile=a.tif foo.pdf -c quit

I would install ghostscript and read the man page for gs to see what exact options are needed and experiment.

How to implement my very own URI scheme on Android

As the question is asked years ago, and Android is evolved a lot on this URI scheme.
From original URI scheme, to deep link, and now Android App Links.

Android now recommends to use HTTP URLs, not define your own URI scheme. Because Android App Links use HTTP URLs that link to a website domain you own, so no other app can use your links. You can check the comparison of deep link and Android App links from here

Now you can easily add a URI scheme by using Android Studio option: Tools > App Links Assistant. Please refer the detail to Android document: https://developer.android.com/studio/write/app-link-indexing.html

how to automatically scroll down a html page?

You can use two different techniques to achieve this.

The first one is with javascript: set the scrollTop property of the scrollable element (e.g. document.body.scrollTop = 1000;).

The second is setting the link to point to a specific id in the page e.g.

<a href="mypage.html#sectionOne">section one</a>

Then if in your target page you'll have that ID the page will be scrolled automatically.

What does the return keyword do in a void method in Java?

It just exits the method at that point. Once return is executed, the rest of the code won't be executed.

eg.

public void test(int n) {
    if (n == 1) {
        return; 
    }
    else if (n == 2) {
        doStuff();
        return;
    }
    doOtherStuff();
}

Note that the compiler is smart enough to tell you some code cannot be reached:

if (n == 3) {
    return;
    youWillGetAnError(); //compiler error here
}

ExecuteNonQuery: Connection property has not been initialized.

A couple of things wrong here.

  1. Do you really want to open and close the connection for every single log entry?

  2. Shouldn't you be using SqlCommand instead of SqlDataAdapter?

  3. The data adapter (or SqlCommand) needs exactly what the error message tells you it's missing: an active connection. Just because you created a connection object does not magically tell C# that it is the one you want to use (especially if you haven't opened the connection).

I highly recommend a C# / SQL Server tutorial.

How to use and style new AlertDialog from appCompat 22.1 and above

To use a theme for all the application, and don't use the second parameter to style your Dialog

<style name="MyTheme" parent="Base.Theme.AppCompat.Light">
    <item name="alertDialogTheme">@style/dialog</item>
    <item name="colorAccent">@color/accent</item>
</style>

<style name="dialog" parent="Base.Theme.AppCompat.Light.Dialog.Alert">
    <item name="colorAccent">@color/accent</item>
</style>

On my app using a color accent in theme don't show the alertDialog's buttons with the theme colorAccent I have to add a dialog style in the theme.

Clear text input on click with AngularJS

Try this,

 this.searchAll = element(by.xpath('path here'));
 this.searchAll.sendKeys('');

Excel formula to get cell color

Anticipating that I already had the answer, which is that there is no built-in worksheet function that returns the background color of a cell, I decided to review this article, in case I was wrong. I was amused to notice a citation to the very same MVP article that I used in the course of my ongoing research into colors in Microsoft Excel.

While I agree that, in the purest sense, color is not data, it is meta-data, and it has uses as such. To that end, I shall attempt to develop a function that returns the color of a cell. If I succeed, I plan to put it into an add-in, so that I can use it in any workbook, where it will join a growing legion of other functions that I think Microsoft left out of the product.

Regardless, IMO, the ColorIndex property is virtually useless, since there is essentially no connection between color indexes and the colors that can be selected in the standard foreground and background color pickers. See Color Combinations: Working with Colors in Microsoft Office and the associated binary workbook, Color_Combinations Workbook.

Import pandas dataframe column as string not int

Just want to reiterate this will work in pandas >= 0.9.1:

In [2]: read_csv('sample.csv', dtype={'ID': object})
Out[2]: 
                           ID
0  00013007854817840016671868
1  00013007854817840016749251
2  00013007854817840016754630
3  00013007854817840016781876
4  00013007854817840017028824
5  00013007854817840017963235
6  00013007854817840018860166

I'm creating an issue about detecting integer overflows also.

EDIT: See resolution here: https://github.com/pydata/pandas/issues/2247

Update as it helps others:

To have all columns as str, one can do this (from the comment):

pd.read_csv('sample.csv', dtype = str)

To have most or selective columns as str, one can do this:

# lst of column names which needs to be string
lst_str_cols = ['prefix', 'serial']
# use dictionary comprehension to make dict of dtypes
dict_dtypes = {x : 'str'  for x in lst_str_cols}
# use dict on dtypes
pd.read_csv('sample.csv', dtype=dict_dtypes)

Visual Studio "Could not copy" .... during build

I was going crazy trying to find why System process held an open handle on the EXE I was working with for another minute after it was terminated, and I was getting the same error as the OP.

The reason was that the previous developers did not wrap IDisposable objects in using(){}. Once the IDisposable objects correctly destroyed themselves, the error occurred no more and I was able to rebuild immediately.

Drop-down menu that opens up/upward with pure css

Add bottom:100% to your #menu:hover ul li:hover ul rule

Demo 1

#menu:hover ul li:hover ul {
    position: absolute;
    margin-top: 1px;
    font: 10px;
    bottom: 100%; /* added this attribute */
}

Or better yet to prevent the submenus from having the same effect, just add this rule

Demo 2

#menu>ul>li:hover>ul { 
    bottom:100%;
}

Demo 3

source: http://jsfiddle.net/W5FWW/4/

And to get back the border you can add the following attribute

#menu>ul>li:hover>ul { 
    bottom:100%;
    border-bottom: 1px solid transparent
}

Python 3 turn range to a list

The reason why Python3 lacks a function for directly getting a ranged list is because the original Python3 designer was quite novice in Python2. He only considered the use of range() function in a for loop, thus, the list should never need to be expanded. In fact, very often we do need to use the range() function to produce a list and pass into a function.

Therefore, in this case, Python3 is less convenient as compared to Python2 because:

  • In Python2, we have xrange() and range();
  • In Python3, we have range() and list(range())

Nonetheless, you can still use list expansion in this way:

[*range(N)]

Is it possible to have a custom facebook like button?

It's possible with a lot of work.

Basically, you have to post likes action via the Open Graph API. Then, you can add a custom design to your like button.

But then, you''ll need to keep track yourself of the likes so a returning user will be able to unlike content he liked previously.

Plus, you'll need to ask user to log into your app and ask them the publish_action permission.

All in all, if you're doing this for an application, it may worth it. For a website where you basically want user to like articles, then this is really to much.

Also, consider that you increase your drop-off rate each time you ask user a permission via a Facebook login.

If you want to see an example, I've recently made an app using the open graph like button, just hover on some photos in the mosaique to see it

Why can't I use a list as a dict key in python?

dict keys need to be hashable. Lists are Mutable and they do not provide a valid hash method.

How do I serialize a Python dictionary into a string, and then back to a dictionary?

While not strictly serialization, json may be reasonable approach here. That will handled nested dicts and lists, and data as long as your data is "simple": strings, and basic numeric types.

How to search and replace text in a file?

I modified Jayram Singh's post slightly in order to replace every instance of a '!' character to a number which I wanted to increment with each instance. Thought it might be helpful to someone who wanted to modify a character that occurred more than once per line and wanted to iterate. Hope that helps someone. PS- I'm very new at coding so apologies if my post is inappropriate in any way, but this worked for me.

f1 = open('file1.txt', 'r')
f2 = open('file2.txt', 'w')
n = 1  

# if word=='!'replace w/ [n] & increment n; else append same word to     
# file2

for line in f1:
    for word in line:
        if word == '!':
            f2.write(word.replace('!', f'[{n}]'))
            n += 1
        else:
            f2.write(word)
f1.close()
f2.close()

Send Message in C#

You don't need to send messages.

Add an event to the one form and an event handler to the other. Then you can use a third project which references the other two to attach the event handler to the event. The two DLLs don't need to reference each other for this to work.

How to use timeit module

The built-in timeit module works best from the IPython command line.

To time functions from within a module:

from timeit import default_timer as timer
import sys

def timefunc(func, *args, **kwargs):
    """Time a function. 

    args:
        iterations=3

    Usage example:
        timeit(myfunc, 1, b=2)
    """
    try:
        iterations = kwargs.pop('iterations')
    except KeyError:
        iterations = 3
    elapsed = sys.maxsize
    for _ in range(iterations):
        start = timer()
        result = func(*args, **kwargs)
        elapsed = min(timer() - start, elapsed)
    print(('Best of {} {}(): {:.9f}'.format(iterations, func.__name__, elapsed)))
    return result

Hide div element when screen size is smaller than a specific size

@media only screen and (max-width: 1026px) { 
  #fadeshow1 { 
    display: none; 
  } 
}

Any time the screen is less than 1026 pixels wide, anything inside the { } will apply.

Some browsers don't support media queries. You can get round this using a javascript library like Respond.JS

Insert a string at a specific index

Here is a method I wrote that behaves like all other programming languages:

_x000D_
_x000D_
String.prototype.insert = function(index, string) {
  if (index > 0) {
    return this.substring(0, index) + string + this.substr(index);
  }

  return string + this;
};

//Example of use:
var something = "How you?";
something = something.insert(3, " are");
console.log(something)
_x000D_
_x000D_
_x000D_

Reference:

How do I create a nice-looking DMG for Mac OS X using command-line tools?

For those of you that are interested in this topic, I should mention how I create the DMG:

hdiutil create XXX.dmg -volname "YYY" -fs HFS+ -srcfolder "ZZZ"

where

XXX == disk image file name (duh!)
YYY == window title displayed when DMG is opened
ZZZ == Path to a folder containing the files that will be copied into the DMG

cmake and libpthread

Here is the right anwser:

ADD_EXECUTABLE(your_executable ${source_files})

TARGET_LINK_LIBRARIES( your_executable
pthread
)

equivalent to

-lpthread

Add space between <li> elements

I just want to say guys:

Only Play With Margin

It is a lot easier to add space between <li> if you play with margin.

Fastest way to add an Item to an Array

Case C) is the fastest. Having this as an extension:

Public Module MyExtensions
    <Extension()> _
    Public Sub Add(Of T)(ByRef arr As T(), item As T)
        Array.Resize(arr, arr.Length + 1)
        arr(arr.Length - 1) = item
    End Sub
End Module

Usage:

Dim arr As Integer() = {1, 2, 3}
Dim newItem As Integer = 4
arr.Add(newItem)

' --> duration for adding 100.000 items: 1 msec
' --> duration for adding 100.000.000 items: 1168 msec

javascript /jQuery - For Loop

Use a regular for loop and format the index to be used in the selector.

var array = [];
for (var i = 0; i < 4; i++) {
    var selector = '' + i;
    if (selector.length == 1)
        selector = '0' + selector;
    selector = '#event' + selector;
    array.push($(selector, response).html());
}

C# string reference type?

The reference to the string is passed by value. There's a big difference between passing a reference by value and passing an object by reference. It's unfortunate that the word "reference" is used in both cases.

If you do pass the string reference by reference, it will work as you expect:

using System;

class Test
{
    public static void Main()
    {
        string test = "before passing";
        Console.WriteLine(test);
        TestI(ref test);
        Console.WriteLine(test);
    }

    public static void TestI(ref string test)
    {
        test = "after passing";
    }
}

Now you need to distinguish between making changes to the object which a reference refers to, and making a change to a variable (such as a parameter) to let it refer to a different object. We can't make changes to a string because strings are immutable, but we can demonstrate it with a StringBuilder instead:

using System;
using System.Text;

class Test
{
    public static void Main()
    {
        StringBuilder test = new StringBuilder();
        Console.WriteLine(test);
        TestI(test);
        Console.WriteLine(test);
    }

    public static void TestI(StringBuilder test)
    {
        // Note that we're not changing the value
        // of the "test" parameter - we're changing
        // the data in the object it's referring to
        test.Append("changing");
    }
}

See my article on parameter passing for more details.

nodejs npm global config missing on windows

It looks like the files npm uses to edit its config files are not created on a clean install, as npm has a default option for each one. This is why you can still get options with npm config get <option>: having those files only overrides the defaults, it doesn't create the options from scratch.

I had never touched my npm config stuff before today, even though I had had it for months now. None of the files were there yet, such as ~/.npmrc (on a Windows 8.1 machine with Git Bash), yet I could run npm config get <something> and, if it was a correct npm option, it returned a value. When I ran npm config set <option> <value>, the file ~/.npmrc seemed to be created automatically, with the option & its value as the only non-commented-out line.

As for deleting options, it looks like this just sets the value back to the default value, or does nothing if that option was never set or was unset & never reset. Additionally, if that option is the only explicitly set option, it looks like ~/.npmrc is deleted, too, and recreated if you set anything else later.

In your case (assuming it is still the same over a year later), it looks like you never set the proxy option in npm. Therefore, as npm's config help page says, it is set to whatever your http_proxy (case-insensitive) environment variable is. This means there is nothing to delete, unless you want to "delete" your HTTP proxy, although you could set the option or environment variable to something else and hope neither breaks your set-up somehow.

How to get the path of the batch script in Windows?

You can use %~dp0, d means the drive only, p means the path only, 0 is the argument for the full filename of the batch file.

For example if the file path was C:\Users\Oliver\Desktop\example.bat then the argument would equal C:\Users\Oliver\Desktop\, also you can use the command set cpath=%~dp0 && set cpath=%cpath:~0,-1% and use the %cpath% variable to remove the trailing slash.

Android XML Percent Symbol

Use

<string name="win_percentage">%d%% wins</string>

to get

80% wins as a formatted string.

I'm using String.format() method to get the number inserted instead of %d.

How do I get first element rather than using [0] in jQuery?

You can use the first method:

$('li').first()

http://api.jquery.com/first/

btw I agree with Nick Craver -- use document.getElementById()...

java create date object using a value string

FIRST OF ALL KNOW THE REASON WHY ECLIPSE IS DOING SO.

Date has only one constructor Date(long date) which asks for date in long data type.

The constructor you are using

Date(String s) Deprecated. As of JDK version 1.1, replaced by DateFormat.parse(String s).

Thats why eclipse tells that this function is not good.

See this official docs

http://docs.oracle.com/javase/6/docs/api/java/util/Date.html


Deprecated methods from your context -- Source -- http://www.coderanch.com/t/378728/java/java/Deprecated-methods

There are a number of reasons why a method or class may become deprecated. An API may not be easily extensible without breaking backwards compatibility, and thus be superseded by a more powerful API (e.g., java.util.Date has been deprecated in favor of Calendar, or the Java 1.0 event model). It may also simply not work or produce incorrect results under certain circumstances (e.g., some of the java.io stream classes do not work properly with some encodings). Sometimes an API is just ill-conceived (SingleThreadModel in the servlet API), and gets replaced by nothing. And some of the early calls have been replaced by "Java Bean"-compatible methods (size by getSize, bounds by getBounds etc.)


SEVRAL SOLUTIONS ARE THERE JUST GOOGLE IT--

You can use date(long date) By converting your date String into long milliseconds and stackoverflow has so many post for that purpose.

converting a date string into milliseconds in java

What is float in Java?

Make it

float b= 3.6f;

A floating-point literal is of type float if it is suffixed with an ASCII letter F or f; otherwise its type is double and it can optionally be suffixed with an ASCII letter D or d

Why do I get permission denied when I try use "make" to install something?

Giving us the whole error message would be much more useful. If it's for make install then you're probably trying to install something to a system directory and you're not root. If you have root access then you can run

sudo make install

or log in as root and do the whole process as root.

How to pass a textbox value from view to a controller in MVC 4?

your link is generated when the page loads therefore it will always have the original value in it. You will need to set the link via javascript

You could also just wrap that in a form and have hidden fields for id, productid, and unitrate

Here's a sample for ya.

HTML

<input type="text" id="ss" value="1"/>
<br/>
<input type="submit" id="go" onClick="changeUrl()"/>
<br/>
<a id="imgUpdate"  href="/someurl?quantity=1">click me</a>

JS

function changeUrl(){
   var url = document.getElementById("imgUpdate").getAttribute('href');
   var inputValue = document.getElementById('ss').value;
   var currentQ = GiveMeTheQueryStringParameterValue("quantity",url);
    url = url.replace("quantity=" + currentQ, "quantity=" + inputValue);
document.getElementById("imgUpdate").setAttribute('href',url)
}

    function GiveMeTheQueryStringParameterValue(parameterName, input) {
    parameterName = parameterName.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
    var regex = new RegExp("[\\?&]" + parameterName + "=([^&#]*)");
    var results = regex.exec(input);
    if (results == null)
        return "";
    else
        return decodeURIComponent(results[1].replace(/\+/g, " "));
}

this could be cleaned up and expanded as you need it but the example works

Make Bootstrap 3 Tabs Responsive

The solution is just 3 lines:

@media only screen and (max-width: 479px) {
   .nav-tabs > li {
      width: 100%;
   }
}

..but you have to accept the idea of tabs that wrap to more lines in other dimensions.

Of course you can achieve a horizontal scrolling area with white-space: nowrap trick but the scrollbars look ugly on desktops so you have to write js code and the whole thing starts becoming no trivial at all!

Failed to import new Gradle project: failed to find Build Tools revision *.0.0

Look in the SDK Manager what is your highest Android SDK Build-tools version, and copy this version number in your project build.gradle file, in the android/buildToolsVersion property (for me, version was "18.1.1").

Hope it help!

Java String - See if a string contains only numbers and not letters

You can use Regex.Match

if(text.matches("\\d*")&& text.length() > 2){
    System.out.println("number");
}

Or you could use onversions like Integer.parseInt(String) or better Long.parseLong(String) for bigger numbers like for example:

private boolean onlyContainsNumbers(String text) {
    try {
        Long.parseLong(text);
        return true;
    } catch (NumberFormatException ex) {
        return false;
    }
} 

And then test with:

if (onlyContainsNumbers(text) && text.length() > 2) {
    // do Stuff
}

Convert multiple rows into one with comma as separator

you can use stuff() to convert rows as comma separated values

select
EmployeeID,
stuff((
  SELECT ',' + FPProjectMaster.GroupName 
      FROM     FPProjectInfo AS t INNER JOIN
              FPProjectMaster ON t.ProjectID = FPProjectMaster.ProjectID
      WHERE  (t.EmployeeID = FPProjectInfo.EmployeeID)
              And t.STatusID = 1
              ORDER BY t.ProjectID
       for xml path('')
       ),1,1,'') as name_csv
from FPProjectInfo
group by EmployeeID;

Thanks @AlexKuznetsov for the reference to get this answer.

failed to resolve com.android.support:appcompat-v7:22 and com.android.support:recyclerview-v7:21.1.2

I solved the problem updating all packages from Android SDK Manager and also, I had to install Extras -> Android Support Repository.

php resize image on upload

If you want to use Imagick out of the box (included with most PHP distributions), it's as easy as...

$image = new Imagick();
$image_filehandle = fopen('some/file.jpg', 'a+');
$image->readImageFile($image_filehandle);

$image->scaleImage(100,200,FALSE);

$image_icon_filehandle = fopen('some/file-icon.jpg', 'a+');
$image->writeImageFile($image_icon_filehandle);

You will probably want to calculate width and height more dynamically based on the original image. You can get an image's current width and height, using the above example, with $image->getImageHeight(); and $image->getImageWidth();

Good tool for testing socket connections?

Hercules is fantastic. It's a fully functioning tcp/udp client/server, amazing for debugging sockets. More details on the web site.

How to download all dependencies and packages to directory

The aptitude --download-only ... approach only works if you have a debian distro with internet connection in your hands.

If you don't, I think it is better to run the following script on the disconnected debian machine:

apt-get --print-uris --yes install <my_package_name> | grep ^\' | cut -d\' -f2 >downloads.list

move the downloads.list file into a connected linux (or non linux) machine, and run:

wget --input-file myurilist

this downloads all your files into the current directory.After that you can copy them on an USB key and install in your disconnected debian machine.

credits: http://www.tuxradar.com/answers/517

PS I basically copied the blog post because it was not very readable, and in case the post will disappear.

Oracle Not Equals Operator

The difference is :

"If you use !=, it returns sub-second. If you use <>, it takes 7 seconds to return. Both return the right answer."

Oracle not equals (!=) SQL operator

Regards

BasicHttpBinding vs WsHttpBinding vs WebHttpBinding

You're comparing apples to oranges here:

  • webHttpBinding is the REST-style binding, where you basically just hit a URL and get back a truckload of XML or JSON from the web service

  • basicHttpBinding and wsHttpBinding are two SOAP-based bindings which is quite different from REST. SOAP has the advantage of having WSDL and XSD to describe the service, its methods, and the data being passed around in great detail (REST doesn't have anything like that - yet). On the other hand, you can't just browse to a wsHttpBinding endpoint with your browser and look at XML - you have to use a SOAP client, e.g. the WcfTestClient or your own app.

So your first decision must be: REST vs. SOAP (or you can expose both types of endpoints from your service - that's possible, too).

Then, between basicHttpBinding and wsHttpBinding, there differences are as follows:

  • basicHttpBinding is the very basic binding - SOAP 1.1, not much in terms of security, not much else in terms of features - but compatible to just about any SOAP client out there --> great for interoperability, weak on features and security

  • wsHttpBinding is the full-blown binding, which supports a ton of WS-* features and standards - it has lots more security features, you can use sessionful connections, you can use reliable messaging, you can use transactional control - just a lot more stuff, but wsHttpBinding is also a lot *heavier" and adds a lot of overhead to your messages as they travel across the network

For an in-depth comparison (including a table and code examples) between the two check out this codeproject article: Differences between BasicHttpBinding and WsHttpBinding

PDF to byte array and vice versa

You basically need a helper method to read a stream into memory. This works pretty well:

public static byte[] readFully(InputStream stream) throws IOException
{
    byte[] buffer = new byte[8192];
    ByteArrayOutputStream baos = new ByteArrayOutputStream();

    int bytesRead;
    while ((bytesRead = stream.read(buffer)) != -1)
    {
        baos.write(buffer, 0, bytesRead);
    }
    return baos.toByteArray();
}

Then you'd call it with:

public static byte[] loadFile(String sourcePath) throws IOException
{
    InputStream inputStream = null;
    try 
    {
        inputStream = new FileInputStream(sourcePath);
        return readFully(inputStream);
    } 
    finally
    {
        if (inputStream != null)
        {
            inputStream.close();
        }
    }
}

Don't mix up text and binary data - it only leads to tears.

How can I read and manipulate CSV file data in C++?

Using boost tokenizer to parse records, see here for more details.

ifstream in(data.c_str());
if (!in.is_open()) return 1;

typedef tokenizer< escaped_list_separator<char> > Tokenizer;

vector< string > vec;
string line;

while (getline(in,line))
{
    Tokenizer tok(line);
    vec.assign(tok.begin(),tok.end());

    /// do something with the record
    if (vec.size() < 3) continue;

    copy(vec.begin(), vec.end(),
         ostream_iterator<string>(cout, "|"));

    cout << "\n----------------------" << endl;
}

SELECT query with CASE condition and SUM()

To get each sum in a separate column:

Select SUM(IF(CPaymentType='Check', CAmount, 0)) as PaymentAmountCheck,
       SUM(IF(CPaymentType='Cash', CAmount, 0)) as PaymentAmountCash
from TableOrderPayment
where CPaymentType IN ('Check','Cash') 
and CDate<=SYSDATETIME() 
and CStatus='Active';

How do you comment out code in PowerShell?

You use the hash mark like this

# This is a comment in Powershell

Wikipedia has a good page for keeping track of how to do comments in several popular languages

http://en.wikipedia.org/wiki/Comparison_of_programming_languages_(syntax)#Comments

What is ModelState.IsValid valid for in ASP.NET MVC in NerdDinner?

All the model fields which have definite types, those should be validated when returned to Controller. If any of the model fields are not matching with their defined type, then ModelState.IsValid will return false. Because, These errors will be added in ModelState.

How to upgrade PowerShell version from 2.0 to 3.0

Download and install from http://www.microsoft.com/en-us/download/details.aspx?id=34595. You need Windows 7 SP1 though.

It's worth keeping in mind that PowerShell 3 on Windows 7 does not have all the cmdlets as PowerShell 3 on Windows 8. So you may still encounter cmdlets that are not present on your system.

Convert String to Type in C#

use following LoadType method to use System.Reflection to load all registered(GAC) and referenced assemblies and check for typeName

public Type[] LoadType(string typeName)
{
    return LoadType(typeName, true);
}

public Type[] LoadType(string typeName, bool referenced)
{
    return LoadType(typeName, referenced, true);
}

private Type[] LoadType(string typeName, bool referenced, bool gac)
{
    //check for problematic work
    if (string.IsNullOrEmpty(typeName) || !referenced && !gac)
        return new Type[] { };

    Assembly currentAssembly = Assembly.GetExecutingAssembly();

    List<string> assemblyFullnames = new List<string>();
    List<Type> types = new List<Type>();

    if (referenced)
    {            //Check refrenced assemblies
        foreach (AssemblyName assemblyName in currentAssembly.GetReferencedAssemblies())
        {
            //Load method resolve refrenced loaded assembly
            Assembly assembly = Assembly.Load(assemblyName.FullName);

            //Check if type is exists in assembly
            var type = assembly.GetType(typeName, false, true);

            if (type != null && !assemblyFullnames.Contains(assembly.FullName))
            {
                types.Add(type);
                assemblyFullnames.Add(assembly.FullName);
            }
        }
    }

    if (gac)
    {
        //GAC files
        string gacPath = Environment.GetFolderPath(System.Environment.SpecialFolder.Windows) + "\\assembly";
        var files = GetGlobalAssemblyCacheFiles(gacPath);
        foreach (string file in files)
        {
            try
            {
                //reflection only
                Assembly assembly = Assembly.ReflectionOnlyLoadFrom(file);

                //Check if type is exists in assembly
                var type = assembly.GetType(typeName, false, true);

                if (type != null && !assemblyFullnames.Contains(assembly.FullName))
                {
                    types.Add(type);
                    assemblyFullnames.Add(assembly.FullName);
                }
            }
            catch
            {
                //your custom handling
            }
        }
    }

    return types.ToArray();
}

public static string[] GetGlobalAssemblyCacheFiles(string path)
{
    List<string> files = new List<string>();

    DirectoryInfo di = new DirectoryInfo(path);

    foreach (FileInfo fi in di.GetFiles("*.dll"))
    {
        files.Add(fi.FullName);
    }

    foreach (DirectoryInfo diChild in di.GetDirectories())
    {
        var files2 = GetGlobalAssemblyCacheFiles(diChild.FullName);
        files.AddRange(files2);
    }

    return files.ToArray();
}

Using CSS how to change only the 2nd column of a table

To change only the second column of a table use the following:

General Case:

table td + td{  /* this will go to the 2nd column of a table directly */

background:red

}

Your case:

.countTable table table td + td{ 

background: red

}

Note: this works for all browsers (Modern and old ones) that's why I added my answer to an old question

Correct way to push into state array

You can use .concat method to create copy of your array with new data:

this.setState({ myArray: this.state.myArray.concat('new value') })

But beware of special behaviour of .concat method when passing arrays - [1, 2].concat(['foo', 3], 'bar') will result in [1, 2, 'foo', 3, 'bar'].

Copy a variable's value into another

For strings or input values you could simply use this:

var a = $('#some_hidden_var').val(),
b = a.substr(0);

Rails.env vs RAILS_ENV

ENV['RAILS_ENV'] is now deprecated.

You should use Rails.env which is clearly much nicer.

Spark - repartition() vs coalesce()

What follows from the code and code docs is that coalesce(n) is the same as coalesce(n, shuffle = false) and repartition(n) is the same as coalesce(n, shuffle = true)

Thus, both coalesce and repartition can be used to increase number of partitions

With shuffle = true, you can actually coalesce to a larger number of partitions. This is useful if you have a small number of partitions, say 100, potentially with a few partitions being abnormally large.

Another important note to accentuate is that if you drastically decrease number of partitions you should consider using shuffled version of coalesce (same as repartition in that case). This will allow your computations be performed in parallel on parent partitions (multiple task).

However, if you're doing a drastic coalesce, e.g. to numPartitions = 1, this may result in your computation taking place on fewer nodes than you like (e.g. one node in the case of numPartitions = 1). To avoid this, you can pass shuffle = true. This will add a shuffle step, but means the current upstream partitions will be executed in parallel (per whatever the current partitioning is).

Please also refer to the related answer here

When to use RDLC over RDL reports?

If you have a reporting services infrastructure available to you, use it. You will find RDL development to be a bit more pleasant. You can preview the report, easily setup parameters, etc.

WPF User Control Parent

Use VisualTreeHelper.GetParent or the recursive function below to find the parent window.

public static Window FindParentWindow(DependencyObject child)
{
    DependencyObject parent= VisualTreeHelper.GetParent(child);

    //CHeck if this is the end of the tree
    if (parent == null) return null;

    Window parentWindow = parent as Window;
    if (parentWindow != null)
    {
        return parentWindow;
    }
    else
    {
        //use recursion until it reaches a Window
        return FindParentWindow(parent);
    }
}

The import android.support cannot be resolved

Please follow these Steps:

For Eclipse:

  • Go to your Project's Properties
  • Navigate to the Java Build Path
  • Then go to the Libraries tab. There click the Add External JARs Button on the Right pane.
  • Select the android-support-v4.jar file, usually the path for the Jar file is :
    YOUR_DRIVE\android-sdks\extras\android\support\v4\android-support-v4.jar
  • After adding android-support-v4.jar Library, navigate to the Order and Export tab and put check mark on the android-support-v4 Library file.
  • After doing the above, Clean the Project and Build it.
  • Problem Solved.

For Android Studio:

Short Version:

  • Add the following line to your build.gradle file:
    implementation 'com.android.support:support-v4:YOUR_TARGET_VERSION'

Long Version:

  • Go to File -> Project Structure

  • Go to "Dependencies" Tab -> Click on the Plus sign -> Go to "Library dependency"

  • Select the support library "support-v4 (com.android.support:support-v4:YOUR_TARGET_VERSION)"

  • Navigate to your "build.gradle" inside your App Directory and double check if your desired Android Support Library has been added to your dependencies.

  • Rebuild your project and now everything should work.

Further reading regarding this Question:

  1. Support Library - Android Dev
  2. Recent Support Library Revisions
  3. Support Library Packages
  4. What is an Android Support Library?
  5. How Android Support Library work?

I hope this helps.

Hide Signs that Meteor.js was Used

A Meteor app does not, by default, add any X-Powered-By headers to HTTP responses, as you might find in various PHP apps. The headers look like:

$ curl -I https://atmosphere.meteor.com  HTTP/1.1 200 OK content-type: text/html; charset=utf-8 date: Tue, 31 Dec 2013 23:12:25 GMT connection: keep-alive 

However, this doesn't mask that Meteor was used. Viewing the source of a Meteor app will look very distinctive.

<script type="text/javascript"> __meteor_runtime_config__ = {"meteorRelease":"0.6.3.1","ROOT_URL":"http://atmosphere.meteor.com","serverId":"62a4cf6a-3b28-f7b1-418f-3ddf038f84af","DDP_DEFAULT_CONNECTION_URL":"ddp+sockjs://ddp--****-atmosphere.meteor.com/sockjs"}; </script> 

If you're trying to avoid people being able to tell you are using Meteor even by viewing source, I don't think that's possible.

How to sort an array of integers correctly

The reason why the sort function behaves so weird

From the documentation:

[...] the array is sorted according to each character's Unicode code point value, according to the string conversion of each element.

If you print the unicode point values of the array then it will get clear.

_x000D_
_x000D_
console.log("140000".charCodeAt(0));_x000D_
console.log("104".charCodeAt(0));_x000D_
console.log("99".charCodeAt(0));_x000D_
_x000D_
//Note that we only look at the first index of the number "charCodeAt(  0  )"
_x000D_
_x000D_
_x000D_

This returns: "49, 49, 57".

49 (unicode value of first number at 140000)
49 (unicode value of first number at 104)
57 (unicode value of first number at 99)

Now, because 140000 and 104 returned the same values (49) it cuts the first index and checks again:

_x000D_
_x000D_
console.log("40000".charCodeAt(0));_x000D_
console.log("04".charCodeAt(0));_x000D_
_x000D_
//Note that we only look at the first index of the number "charCodeAt(  0  )"
_x000D_
_x000D_
_x000D_

52 (unicode value of first number at 40000)
40 (unicode value of first number at 04)

If we sort this, then we will get:

40 (unicode value of first number at 04)
52 (unicode value of first number at 40000)

so 104 comes before 140000.

So the final result will be:

_x000D_
_x000D_
var numArray = [140000, 104, 99];_x000D_
numArray = numArray.sort();_x000D_
console.log(numArray)
_x000D_
_x000D_
_x000D_

104, 140000, 99

Conclusion:

sort() does sorting by only looking at the first index of the numbers. sort() does not care if a whole number is bigger than another, it compares the value of the unicode of the digits, and if there are two equal unicode values, then it checks if there is a next digit and compares it as well.

To sort correctly, you have to pass a compare function to sort() like explained here.

Get spinner selected items text?

Spinner returns you the integer value for the array. You have to retrieve the string value based of the index.

Spinner MySpinner = (Spinner)findViewById(R.id.spinner);
Integer indexValue = MySpinner.getSelectedItemPosition();

Use URI builder in Android or create URL with variables

Best answer: https://stackoverflow.com/a/19168199/413127

Example for

 http://api.example.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7

Now with Kotlin

 val myUrl = Uri.Builder().apply {
        scheme("https")
        authority("www.myawesomesite.com")
        appendPath("turtles")
        appendPath("types")
        appendQueryParameter("type", "1")
        appendQueryParameter("sort", "relevance")
        fragment("section-name")
        build()            
    }.toString()

Query to list number of records in each table in a database

You can copy, past and execute this piece of code to get all table record counts into a table. Note: Code is commented with instructions

create procedure RowCountsPro
as
begin
--drop the table if exist on each exicution
IF OBJECT_ID (N'dbo.RowCounts', N'U') IS NOT NULL 
DROP TABLE dbo.RowCounts;
-- creating new table
CREATE TABLE RowCounts 
( [TableName]            VARCHAR(150)
, [RowCount]               INT
, [Reserved]                 NVARCHAR(50)
, [Data]                        NVARCHAR(50)
, [Index_Size]               NVARCHAR(50)
, [UnUsed]                   NVARCHAR(50))
--inserting all records
INSERT INTO RowCounts([TableName], [RowCount],[Reserved],[Data],[Index_Size],[UnUsed])
--  "sp_MSforeachtable" System Procedure, 'sp_spaceused "?"' param to get records and resources used
EXEC sp_MSforeachtable 'sp_spaceused "?"' 
-- selecting data and returning a table of data
SELECT [TableName], [RowCount],[Reserved],[Data],[Index_Size],[UnUsed]
FROM RowCounts
ORDER BY [TableName]
end

I have tested this code and it works fine on SQL Server 2014.

Display Back Arrow on Toolbar

Simple and easy way to show back button on toolbar

Paste this code in onCreate method

 if (getSupportActionBar() != null){

            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setDisplayShowHomeEnabled(true);
        }

Paste this override method outside the onCreate method

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if(item.getItemId()== android.R.id.home) {

        finish();
    }
    return super.onOptionsItemSelected(item);
}

Django request.GET

Calling /search/ should result in "you submitted nothing", but calling /search/?q= on the other hand should result in "you submitted u''"

Browsers have to add the q= even when it's empty, because they have to include all fields which are part of the form. Only if you do some DOM manipulation in Javascript (or a custom javascript submit action), you might get such a behavior, but only if the user has javascript enabled. So you should probably simply test for non-empty strings, e.g:

if request.GET.get('q'):
    message = 'You submitted: %r' % request.GET['q']
else:
    message = 'You submitted nothing!'

Oracle - What TNS Names file am I using?

Not direct answer to your question, but I've been quite frustrated myself trying find and update all of the tnsnames files, as I had several oracle installs: Client, BI tools, OWB, etc, each of which had its own oracle home. I ended up creating a utility called TNSNamesSync that will update all of the tnsnames in all of the oracle homes. It's under the MIT license, free to use here https://github.com/artybug/TNSNamesSync/releases

The docs are here: https://github.com/artchik/TNSNamesSync/blob/master/README.md

This is for Windows only, though.

SQL LIKE condition to check for integer?

In PostreSQL you can use SIMILAR TO operator (more):

-- only digits
select * from books where title similar to '^[0-9]*$';
-- start with digit
select * from books where title similar to '^[0-9]%$';

How do I check if a given string is a legal/valid file name under Windows?

I got this idea from someone. - don't know who. Let the OS do the heavy lifting.

public bool IsPathFileNameGood(string fname)
{
    bool rc = Constants.Fail;
    try
    {
        this._stream = new StreamWriter(fname, true);
        rc = Constants.Pass;
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Problem opening file");
        rc = Constants.Fail;
    }
    return rc;
}

C++: Converting Hexadecimal to Decimal

only use:

cout << dec << 0x;

Change Date Format(DD/MM/YYYY) in SQL SELECT Statement

There's also another way to do this-

select TO_CHAR(SA.[RequestStartDate] , 'DD/MM/YYYY') as RequestStartDate from ... ;

How can I set size of a button?

GridLayout is often not the best choice for buttons, although it might be for your application. A good reference is the tutorial on using Layout Managers. If you look at the GridLayout example, you'll see the buttons look a little silly -- way too big.

A better idea might be to use a FlowLayout for your buttons, or if you know exactly what you want, perhaps a GroupLayout. (Sun/Oracle recommend that GroupLayout or GridBag layout are better than GridLayout when hand-coding.)

How to use CSS to surround a number with a circle?

Improving the first answer just get rid of the padding and add line-height and vertical-align:

.numberCircle {
   border-radius: 50%;       

   width: 36px;
   height: 36px;
   line-height: 36px;
   vertical-align:middle;

   background: #fff;
   border: 2px solid #666;
   color: #666;

   text-align: center;
   font: 32px Arial, sans-serif;
}

Sending an Intent to browser to open specific URL

The shortest version.

startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.google.com")));

How to get parameters from the URL with JSP

page 1 : Detail page 2 : <% String id = request.getParameter("userid");%> // now you can using id for sql query of hsql detail product

UIScrollView scroll to bottom programmatically

If you somehow change scrollView contentSize (ex. add something to stackView which is inside scrollView) you must call scrollView.layoutIfNeeded() before scrolling, otherwise it does nothing.

Example:

scrollView.layoutIfNeeded()
let bottomOffset = CGPoint(x: 0, y: scrollView.contentSize.height - scrollView.bounds.size.height + scrollView.contentInset.bottom)
if(bottomOffset.y > 0) {
    scrollView.setContentOffset(bottomOffset, animated: true)
}

Java check if boolean is null

The only thing that can be a null is a non-primivite.

A boolean which can only hold TRUE or FALSE is a primitive. The TRUE/FALSE in memory are actually numbers (0 and 1)

0 = FALSE

1 = TRUE

So when you instantiate an object it will be null String str; // will equal null

On the other hand if you instaniate a primitive it will be assigned to 0 default.

boolean isTrue; // will be 0

int i; // will be 0

Seeing the console's output in Visual Studio 2010?

You could create 2 small methods, one that can be called at the beginning of the program, the other at the end. You could also use Console.Read(), so that the program doesn't close after the last write line.

This way you can determine when your functionality gets executed and also when the program exists.

startProgram()
{
     Console.WriteLine("-------Program starts--------");
     Console.Read();
}


endProgram()
{
    Console.WriteLine("-------Program Ends--------");
    Console.Read();
}

horizontal line and right way to code it in html, css

This is relatively simple example and worked for me.

hr {
    width: 70%;
    margin-left: auto;
    margin-right: auto;
}

Resource: https://www.w3docs.com/snippets/css/how-to-style-a-horizontal-line.html

What are the integrity and crossorigin attributes?

integrity - defines the hash value of a resource (like a checksum) that has to be matched to make the browser execute it. The hash ensures that the file was unmodified and contains expected data. This way browser will not load different (e.g. malicious) resources. Imagine a situation in which your JavaScript files were hacked on the CDN, and there was no way of knowing it. The integrity attribute prevents loading content that does not match.

Invalid SRI will be blocked (Chrome developer-tools), regardless of cross-origin. Below NON-CORS case when integrity attribute does not match:

enter image description here

Integrity can be calculated using: https://www.srihash.org/ Or typing into console (link):

openssl dgst -sha384 -binary FILENAME.js | openssl base64 -A

crossorigin - defines options used when the resource is loaded from a server on a different origin. (See CORS (Cross-Origin Resource Sharing) here: https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS). It effectively changes HTTP requests sent by the browser. If the “crossorigin” attribute is added - it will result in adding origin: <ORIGIN> key-value pair into HTTP request as shown below.

enter image description here

crossorigin can be set to either “anonymous” or “use-credentials”. Both will result in adding origin: into the request. The latter however will ensure that credentials are checked. No crossorigin attribute in the tag will result in sending a request without origin: key-value pair.

Here is a case when requesting “use-credentials” from CDN:

<script 
        src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"
        integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" 
        crossorigin="use-credentials"></script>

A browser can cancel the request if crossorigin incorrectly set.

enter image description here

Links
- https://www.w3.org/TR/cors/
- https://tools.ietf.org/html/rfc6454
- https://developer.mozilla.org/en-US/docs/Web/HTML/Element/link

Blogs
- https://frederik-braun.com/using-subresource-integrity.html
- https://web-security.guru/en/web-security/subresource-integrity

How to turn on front flash light programmatically in Android?

From my experience, if your application is designed to work in both portrait and landscape orientation, you need to declare the variable cam as static. Otherwise, onDestroy(), which is called on switching orientation, destroys it but doesn't release Camera so it's not possible to reopen it again.

package com.example.flashlight;

import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.view.Menu;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {

public static Camera cam = null;// has to be static, otherwise onDestroy() destroys it

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

public void flashLightOn(View view) {

    try {
        if (getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA_FLASH)) {
            cam = Camera.open();
            Parameters p = cam.getParameters();
            p.setFlashMode(Parameters.FLASH_MODE_TORCH);
            cam.setParameters(p);
            cam.startPreview();
        }
    } catch (Exception e) {
        e.printStackTrace();
        Toast.makeText(getBaseContext(), "Exception flashLightOn()",
                Toast.LENGTH_SHORT).show();
    }
}

public void flashLightOff(View view) {
    try {
        if (getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA_FLASH)) {
            cam.stopPreview();
            cam.release();
            cam = null;
        }
    } catch (Exception e) {
        e.printStackTrace();
        Toast.makeText(getBaseContext(), "Exception flashLightOff",
                Toast.LENGTH_SHORT).show();
    }
}
}

to manifest I had to put this line

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

from http://developer.android.com/reference/android/hardware/Camera.html

suggested lines above wasn't working for me.