Programs & Examples On #Scaffold

Flutter: RenderBox was not laid out

The problem is that you are placing the ListView inside a Column/Row. The text in the exception gives a good explanation of the error.

To avoid the error you need to provide a size to the ListView inside.

I propose you this code that uses an Expanded to inform the horizontal size (maximum available) and the SizedBox (Could be a Container) for the height:

    new Row(
      children: <Widget>[
        Expanded(
          child: SizedBox(
            height: 200.0,
            child: new ListView.builder(
              scrollDirection: Axis.horizontal,
              itemCount: products.length,
              itemBuilder: (BuildContext ctxt, int index) {
                return new Text(products[index]);
              },
            ),
          ),
        ),
        new IconButton(
          icon: Icon(Icons.remove_circle),
          onPressed: () {},
        ),
      ],
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
    )

,

Flutter - The method was called on null

The reason for this error occurs is that you are using the CryptoListPresenter _presenter without initializing.

I found that CryptoListPresenter _presenter would have to be initialized to fix because _presenter.loadCurrencies() is passing through a null variable at the time of instantiation;

there are two ways to initialize

  1. Can be initialized during an declaration, like this

    CryptoListPresenter _presenter = CryptoListPresenter();
    
  2. In the second, initializing(with assigning some value) it when initState is called, which the framework will call this method once for each state object.

    @override
    void initState() {
      _presenter = CryptoListPresenter(...);
    }
    

How to scroll page in flutter

Very easy if you are already using a statelessWidget checkOut my code

class _MyThirdPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Understanding Material-Cards'),
      ),
      body: SingleChildScrollView(
          child: Column(
        children: <Widget>[
          _buildStack(),
          _buildCard(),
          SingleCard(),
          _inkwellCard()
        ],
      )),
    );
  }
}

Flutter : Vertically center column

Another Solution!

If you want to set widgets in center vertical form, you can use ListView for it. for eg: I used three buttons and add them inside ListView which followed by

shrinkWrap: true -> With this ListView only occupies the space which needed.

import 'package:flutter/material.dart';

class List extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final button1 =
        new RaisedButton(child: new Text("Button1"), onPressed: () {});
    final button2 =
        new RaisedButton(child: new Text("Button2"), onPressed: () {});
    final button3 =
        new RaisedButton(child: new Text("Button3"), onPressed: () {});
    final body = new Center(
      child: ListView(
        shrinkWrap: true,
        children: <Widget>[button1, button2, button3],
     ),
    );

    return new Scaffold(
        appBar: new AppBar(
          title: Text("Sample"),
        ),
        body: body);
  }
}    
void main() {
  runApp(new MaterialApp(
    home: List(),
  ));
}

Output: enter image description here

How to add image in Flutter

their is no need to create asset directory and under it images directory and then you put image. Better is to just create Images directory inside your project where pubspec.yaml exist and put images inside it and access that images just like as shown in tutorial/documention

assets: - images/lake.jpg // inside pubspec.yaml

How to remove package using Angular CLI?

npm uninstal @angular/material

and also clear file custom-theme.scss

How to set the width of a RaisedButton in Flutter?

i would recommend using a MaterialButton, than you can do it like this:

new MaterialButton( 
 height: 40.0, 
 minWidth: 70.0, 
 color: Theme.of(context).primaryColor, 
 textColor: Colors.white, 
 child: new Text("push"), 
 onPressed: () => {}, 
 splashColor: Colors.redAccent,
)

How to clear Flutter's Build cache?

Build cache is generated on application run time when a temporary file automatically generated in dart-tools folder, android folder and iOS folder. Clear command will delete the build tools and dart directories in flutter project so when we re-compile the project it will start from beginning. This command is mostly used when our project is showing debug error or running related error. In this answer we would Clear Build Cache in Flutter Android iOS App and Rebuild Project structure again.

  1. Open your flutter project folder in Command Prompt or Terminal. and type flutter clean command and press enter.

  2. After executing flutter clean command we would see that it will delete the dart-tools folder, android folder and iOS folder in our application with debug file. This might take some time depending upon your system speed to clean the project.

For more info, see https://flutter-examples.com/clear-build-cache-in-flutter-app/

How to Set/Update State of StatefulWidget from other StatefulWidget in Flutter?

Here is the solution which worked for me.

OUTPUT: State of Cart Widget is updated, upon addition of items.

enter image description here

Create a globalKey for the widget you want to update by calling the trigger from anywhere

final GlobalKey<CartWidgetState> cartKey = GlobalKey();

Make sure it's saved in a file have global access such that, it can be accessed from anywhere. I save it in globalClass where is save commonly used variables through the app's state.

class CartWidget extends StatefulWidget {

  CartWidget({Key key}) : super(key: key);
  @override
  CartWidgetState createState() => CartWidgetState();
}

class CartWidgetState extends State<CartWidget> {
  @override
  Widget build(BuildContext context) {
    //return your widget
    return Container();
  }
}

Call your widget from some other class.

class HomeScreen extends StatefulWidget {

  HomeScreen ({Key key}) : super(key: key);
  @override
  HomeScreenState createState() => HomeScreen State();
}

class HomeScreen State extends State<HomeScreen> {
  @override
  Widget build(BuildContext context) {
    return ListView(
              children:[
                 ChildScreen(), 
                 CartWidget(key:cartKey)
              ]
            );
  }
}



class ChildScreen extends StatefulWidget {

  ChildScreen ({Key key}) : super(key: key);
  @override
  ChildScreenState createState() => ChildScreen State();
}

class ChildScreen State extends State<ChildScreen> {
  @override
  Widget build(BuildContext context) {
    return InkWell(
              onTap: (){
                // This will update the state of your inherited widget/ class
                if (cartKey.currentState != null)
                    cartKey.currentState.setState(() {});
              },
              child: Text("Update The State of external Widget"),
           );
  }
}

How to work with progress indicator in flutter?

Centered on screen:

Column(
    mainAxisAlignment: MainAxisAlignment.center,
    mainAxisSize: MainAxisSize.max,
    crossAxisAlignment: CrossAxisAlignment.start,
    children: [
        Row(
            mainAxisAlignment: MainAxisAlignment.center,
            mainAxisSize: MainAxisSize.max,
            children: [CircularProgressIndicator()])
      ])

How to add a ListView to a Column in Flutter?

Reason for the error:

Column expands to the maximum size in main axis direction (vertical axis), and so does the ListView.

Solutions

So, you need to constrain the height of the ListView. There are many ways of doing it, you can choose that best suits your need.


  1. If you want to allow ListView to take up all remaining space inside Column use Expanded.

    Column(
      children: <Widget>[
        Expanded(
          child: ListView(...),
        )
      ],
    )
    

  1. If you want to limit your ListView to certain height, you can use SizedBox.

    Column(
      children: <Widget>[
        SizedBox(
          height: 200, // constrain height
          child: ListView(),
        )
      ],
    )
    

  1. If your ListView is small, you may try shrinkWrap property on it.

    Column(
      children: <Widget>[
        ListView(
          shrinkWrap: true, // use it
        )
      ],
    )
    

How can I dismiss the on screen keyboard?

This may simplify the case. Below code will work only if keyboard is open

if(FocusScope.of(context).isFirstFocus) {
 FocusScope.of(context).requestFocus(new FocusNode());
}

Flutter - Wrap text on overflow, like insert ellipsis or fade

Using Ellipsis

Text(
  "This is a long text",
  overflow: TextOverflow.ellipsis,
),

enter image description here


Using Fade

Text(
  "This is a long text",
  overflow: TextOverflow.fade,
  maxLines: 1,
  softWrap: false,
),

enter image description here


Using Clip

Text(
  "This is a long text",
  overflow: TextOverflow.clip,
  maxLines: 1,
  softWrap: false,
),

enter image description here


Note:

If you are using Text inside a Row, you can put above Text inside Expanded like:

Expanded(
  child: AboveText(),
)

How do I Set Background image in Flutter?

decoration: BoxDecoration(
      image: DecorationImage(
        image: ExactAssetImage("images/background.png"),
        fit: BoxFit.cover
      ),
    ),

this also works inside a container.

Adding a splash screen to Flutter apps

The code from Jaldhi Bhatt doesn't works for me.

Flutter throws a 'Navigator operation requested with a context that does not include a Navigator.'

I fixed the code wrapping the Navigator consumer component inside of another component that initialize the Navigator context using routes, as mentioned in this article.

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:my-app/view/main-view.dart';

class SplashView extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
        home: Builder(
          builder: (context) => new _SplashContent(),
        ),
        routes: <String, WidgetBuilder>{
          '/main': (BuildContext context) => new MainView()}
    );
  }
}

class _SplashContent extends StatefulWidget{

  @override
  _SplashContentState createState() => new _SplashContentState();
}

class _SplashContentState extends State<_SplashContent>
    with SingleTickerProviderStateMixin {

  var _iconAnimationController;
  var _iconAnimation;

  startTimeout() async {
    var duration = const Duration(seconds: 3);
    return new Timer(duration, handleTimeout);
  }

  void handleTimeout() {
    Navigator.pushReplacementNamed(context, "/main");
  }

  @override
  void initState() {
    super.initState();

    _iconAnimationController = new AnimationController(
        vsync: this, duration: new Duration(milliseconds: 2000));

    _iconAnimation = new CurvedAnimation(
        parent: _iconAnimationController, curve: Curves.easeIn);
    _iconAnimation.addListener(() => this.setState(() {}));

    _iconAnimationController.forward();

    startTimeout();
  }

  @override
  Widget build(BuildContext context) {
    return new Center(
        child: new Image(
          image: new AssetImage("images/logo.png"),
          width: _iconAnimation.value * 100,
          height: _iconAnimation.value * 100,
        )
    );
  }
}

How to unapply a migration in ASP.NET Core with EF Core

To completely remove all migrations and start all over again, do the following:

dotnet ef database update 0
dotnet ef migrations remove

Lazy Loading vs Eager Loading

It is better to use eager loading when it is possible, because it optimizes the performance of your application.

ex-:

Eager loading

var customers= _context.customers.Include(c=> c.membershipType).Tolist();

lazy loading

In model customer has to define

Public virtual string membershipType {get; set;}

So when querying lazy loading is much slower loading all the reference objects, but eager loading query and select only the object which are relevant.

Entity Framework rollback and remove bad migration

For those using EF Core with ASP.NET Core v1.0.0 I had a similar problem and used the following commands to correct it (@DavidSopko's post pointed me in the right direction, but the details are slightly different for EF Core):

Update-Database <Name of last good migration>
Remove-Migration

For example, in my current development the command became

PM> Update-Database CreateInitialDatabase
Done.
PM> Remove-Migration
Done.
PM> 

The Remove-Migration will remove the last migration you applied. If you have a more complex scenario with multiple migrations to remove (I only had 2, the initial and the bad one), I suggest you test the steps in a dummy project.

There doesn't currently appear to be a Get-Migrations command in EF Core (v1.0.0) so you must look in your migrations folder and be familiar with what you have done. However, there is a nice help command:

PM> get-help entityframework

Refreshing dastabase in VS2015 SQL Server Object Explorer, all of my data was preserved and the migration that I wanted to revert was gone :)

Initially I tried Remove-Migration by itself and found the error command confusing:

System.InvalidOperationException: The migration '...' has already been applied to the database. Unapply it and try again. If the migration has been applied to other databases, consider reverting its changes using a new migration.

There are already suggestions on improving this wording, but I'd like the error to say something like this:

Run Update-Database (last good migration name) to revert the database schema back to to that state. This command will unapply all migrations that occurred after the migration specified to Update-Database. You may then run Remove-Migration (migration name to remove)

Output from the EF Core help command follows:

 PM> get-help entityframework
                     _/\__
               ---==/    \\
         ___  ___   |.    \|\
        | __|| __|  |  )   \\\
        | _| | _|   \_/ |  //|\\
        |___||_|       /   \\\/\\

TOPIC
    about_EntityFrameworkCore

SHORT DESCRIPTION
    Provides information about Entity Framework Core commands.

LONG DESCRIPTION
    This topic describes the Entity Framework Core commands. See https://docs.efproject.net for information on Entity Framework Core.

    The following Entity Framework cmdlets are included.

        Cmdlet                      Description
        --------------------------  ---------------------------------------------------
        Add-Migration               Adds a new migration.

        Remove-Migration            Removes the last migration.

        Scaffold-DbContext          Scaffolds a DbContext and entity type classes for a specified database.

        Script-Migration            Generates a SQL script from migrations.

        Update-Database             Updates the database to a specified migration.

        Use-DbContext               Sets the default DbContext to use.

SEE ALSO
    Add-Migration
    Remove-Migration
    Scaffold-DbContext
    Script-Migration
    Update-Database
    Use-DbContext

Tried to Load Angular More Than Once

The problem could occur when $templateCacheProvider is trying to resolve a template in the templateCache or through your project directory that does not exist

Example:

templateUrl: 'views/wrongPathToTemplate'

Should be:

templateUrl: 'views/home.html'

ASP.NET Identity DbContext confusion

I would use a single Context class inheriting from IdentityDbContext. This way you can have the context be aware of any relations between your classes and the IdentityUser and Roles of the IdentityDbContext. There is very little overhead in the IdentityDbContext, it is basically a regular DbContext with two DbSets. One for the users and one for the roles.

Entity framework self referencing loop detected

The main problem is that serializing an entity model which has relation with other entity model(Foreign key relationship). This relation causes self referencing this will throw exception while serialization to json or xml. There are lots of options. Without serializing entity models by using custom models.Values or data from entity model data mapped to custom models(object mapping) using Automapper or Valueinjector then return request and it will serialize without any other issues. Or you can serialize entity model so first disable proxies in entity model

public class LabEntities : DbContext
{
   public LabEntities()
   {
      Configuration.ProxyCreationEnabled = false;
   }

To preserve object references in XML, you have two options. The simpler option is to add [DataContract(IsReference=true)] to your model class. The IsReference parameter enables oibject references. Remember that DataContract makes serialization opt-in, so you will also need to add DataMember attributes to the properties:

[DataContract(IsReference=true)]
public partial class Employee
{
   [DataMember]
   string dfsd{get;set;}
   [DataMember]
   string dfsd{get;set;}
   //exclude  the relation without giving datamember tag
   List<Department> Departments{get;set;}
}

In Json format in global.asax

var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling = 
    Newtonsoft.Json.PreserveReferencesHandling.All;

in xml format

var xml = GlobalConfiguration.Configuration.Formatters.XmlFormatter;
var dcs = new DataContractSerializer(typeof(Employee), null, int.MaxValue, 
    false, /* preserveObjectReferences: */ true, null);
xml.SetSerializer<Employee>(dcs);

Bootstrap combining rows (rowspan)

Paul's answer seems to defeat the purpose of bootstrap; that of being responsive to the viewport / screen size.

By nesting rows and columns you can achieve the same result, while retaining responsiveness.

Here is an up-to-date response to this problem;

_x000D_
_x000D_
<div class="container-fluid">_x000D_
  <h1>  Responsive Nested Bootstrap </h1> _x000D_
  <div class="row">_x000D_
    <div class="col-md-5" style="background-color:red;">Span 5</div>_x000D_
    <div class="col-md-3" style="background-color:blue;">Span 3</div>_x000D_
    <div class="col-md-2">_x000D_
      <div class="row">_x000D_
        <div class="container" style="background-color:green;">Span 2</div>_x000D_
      </div>_x000D_
      <div class="row">_x000D_
        <div class="container" style="background-color:purple;">Span 2</div>_x000D_
      </div>_x000D_
    </div>_x000D_
    <div class="col-md-2" style="background-color:yellow;">Span 2</div>_x000D_
  </div>_x000D_
  _x000D_
  <div class="row">_x000D_
    <div class="col-md-6">_x000D_
      <div class="row">_x000D_
        <div class="container" style="background-color:yellow;">Span 6</div>_x000D_
      </div>_x000D_
      <div class="row">_x000D_
        <div class="container" style="background-color:green;">Span 6</div>_x000D_
      </div>_x000D_
    </div>_x000D_
    <div class="col-md-6" style="background-color:red;">Span 6</div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

You can view the codepen here.

Rails 4 Authenticity Token

This is a security feature in Rails. Add this line of code in the form:

<%= hidden_field_tag :authenticity_token, form_authenticity_token %>

Documentation can be found here: http://api.rubyonrails.org/classes/ActionController/RequestForgeryProtection.html

How to have a drop down <select> field in a rails form?

This is a long way round, but if you have not yet implemented then you can originally create your models this way. The method below describes altering an existing database.

1) Create a new model for the email providers:
$ rails g model provider name

2) This will create your model with a name string and timestamps. It also creates the migration which we need to add to the schema with:
$ rake db:migrate

3) Add a migration to add the providers ID into the Contact:
$ rails g migration AddProviderRefToContacts provider:references

4) Go over the migration file to check it look OK, and migrate that too:
$ rake db:migrate

5) Okay, now we have a provider_id, we no longer need the original email_provider string:
$ rails g migration RemoveEmailProviderFromContacts

6) Inside the migration file, add the change which will look something like:

class RemoveEmailProviderFromContacts < ActiveRecord::Migration
  def change
    remove_column :contacts, :email_provider
  end
end

7) Once that is done, migrate the change:
$ rake db:migrate

8) Let's take this moment to update our models:
Contact: belongs_to :provider
Provider: has_many :contacts

9) Then, we set up the drop down logic in the _form.html.erb partial in the views:

  <div class="field">
    <%= f.label :provider %><br>
    <%= f.collection_select :provider_id, Provider.all, :id, :name %>
  </div>

10) Finally, we need to add the provders themselves. One way top do that would be to use the seed file:

Provider.destroy_all

gmail = Provider.create!(name: "gmail")
yahoo = Provider.create!(name: "yahoo")
msn = Provider.create!(name: "msn")

$ rake db:seed

How do I bottom-align grid elements in bootstrap fluid layout

This is based on cfx's solution, but rather than setting the font size to zero in the parent container to remove the inter-column spaces added because of the display: inline-block and having to reset them, I simply added

_x000D_
_x000D_
.row.row-align-bottom > div {_x000D_
    float: none;_x000D_
    display: inline-block;_x000D_
    vertical-align: bottom;_x000D_
    margin-right: -0.25em;_x000D_
}
_x000D_
_x000D_
_x000D_

to the column divs to compensate.

Fluid or fixed grid system, in responsive design, based on Twitter Bootstrap

When you decide between fixed width and fluid width you need to think in terms of your ENTIRE page. Generally, you want to pick one or the other, but not both. The examples you listed in your question are, in-fact, in the same fixed-width page. In other words, the Scaffolding page is using a fixed-width layout. The fixed grid and fluid grid on the Scaffolding page are not meant to be examples, but rather the documentation for implementing fixed and fluid width layouts.

The proper fixed width example is here. The proper fluid width example is here.

When observing the fixed width example, you should not see the content changing sizes when your browser is greater than 960px wide. This is the maximum (fixed) width of the page. Media queries in a fixed-width design will designate the minimum widths for particular styles. You will see this in action when you shrink your browser window and see the layout snap to a different size.

Conversely, the fluid-width layout will always stretch to fit your browser window, no matter how wide it gets. The media queries indicate when the styles change, but the width of containers are always a percentage of your browser window (rather than a fixed number of pixels).

The 'responsive' media queries are all ready to go. You just need to decide if you want to use a fixed width or fluid width layout for your page.

Previously, in bootstrap 2, you had to use row-fluid inside a fluid container and row inside a fixed container. With the introduction of bootstrap 3, row-fluid was removed, do no longer use it.

EDIT: As per the comments, some jsFiddles for:

These fiddles are completely Bootstrap-free, based on pure CSS media queries, which makes them a good starting point, for anyone willing to craft similar solution without using Twitter Bootstrap.

C# ASP.NET MVC Return to Previous Page

I am assuming (please correct me if I am wrong) that you want to re-display the edit page if the edit fails and to do this you are using a redirect.

You may have more luck by just returning the view again rather than trying to redirect the user, this way you will be able to use the ModelState to output any errors too.

Edit:

Updated based on feedback. You can place the previous URL in the viewModel, add it to a hidden field then use it again in the action that saves the edits.

For instance:

public ActionResult Index()
{
    return View();
}

[HttpGet] // This isn't required
public ActionResult Edit(int id)
{
   // load object and return in view
   ViewModel viewModel = Load(id);

   // get the previous url and store it with view model
   viewModel.PreviousUrl = System.Web.HttpContext.Current.Request.UrlReferrer;

   return View(viewModel);
}

[HttpPost]
public ActionResult Edit(ViewModel viewModel)
{
   // Attempt to save the posted object if it works, return index if not return the Edit view again

   bool success = Save(viewModel);
   if (success)
   {
       return Redirect(viewModel.PreviousUrl);
   }
   else
   {
      ModelState.AddModelError("There was an error");
      return View(viewModel);
   }
}

The BeginForm method for your view doesn't need to use this return URL either, you should be able to get away with:

@model ViewModel

@using (Html.BeginForm())
{
    ...
    <input type="hidden" name="PreviousUrl" value="@Model.PreviousUrl" />
}

Going back to your form action posting to an incorrect URL, this is because you are passing a URL as the 'id' parameter, so the routing automatically formats your URL with the return path.

This won't work because your form will be posting to an controller action that won't know how to save the edits. You need to post to your save action first, then handle the redirect within it.

Rails: How does the respond_to block work?

There is one more thing you should be aware of - MIME.

If you need to use a MIME type and it isn't supported by default, you can register your own handlers in config/initializers/mime_types.rb:

Mime::Type.register "text/markdown", :markdown

Adding a column to an existing table in a Rails migration

If you have already run your original migration (before editing it), then you need to generate a new migration (rails generate migration add_email_to_users email:string will do the trick). It will create a migration file containing line: add_column :users, email, string Then do a rake db:migrate and it'll run the new migration, creating the new column.

If you have not yet run the original migration you can just edit it, like you're trying to do. Your migration code is almost perfect: you just need to remove the add_column line completely (that code is trying to add a column to a table, before the table has been created, and your table creation code has already been updated to include a t.string :email anyway).

Differences between Html.TextboxFor and Html.EditorFor in MVC and Razor

This is one of the basic differences not mentioned in previous comments:
Readonly property will work with textbox for and it will not work with EditorFor.

@Html.TextBoxFor(model => model.DateSoldOn, new { @readonly = "readonly" })

Above code works, where as with following you can't make control to readonly.

@Html.EditorFor(model => model.DateSoldOn, new { @readonly = "readonly" })

Rails: How to run `rails generate scaffold` when the model already exists?

This command should do the trick:

$ rails g scaffold movie --skip

Undo scaffolding in Rails

For generating scaffold in rails -

rails generate scaffold MODEL_GOES_HERE

For undo scaffold in rails -

rails destroy scaffold MODEL_GOES_HERE

Setting the default value of a DateTime Property to DateTime.Now inside the System.ComponentModel Default Value Attrbute

You cannot do this with an attribute because they are just meta information generated at compile time. Just add code to the constructor to initialize the date if required, create a trigger and handle missing values in the database, or implement the getter in a way that it returns DateTime.Now if the backing field is not initialized.

public DateTime DateCreated
{
   get
   {
      return this.dateCreated.HasValue
         ? this.dateCreated.Value
         : DateTime.Now;
   }

   set { this.dateCreated = value; }
}

private DateTime? dateCreated = null;

Allow all remote connections, MySQL

Install and setup mysql to connect from anywhere remotely DOES NOT WORK WITH mysql_secure_installation ! (https://dev.mysql.com/doc/refman/5.5/en/mysql-secure-installation.html)

On Ubuntu, Install mysql using:

sudo apt-get install mysql-server

Have just the below in /etc/mysql/my.cnf

[mysqld]
#### Unix socket settings (making localhost work)
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock

#### TCP Socket settings (making all remote logins work)
port            = 3306
bind-address = 0.0.0.0

Login into DB from server using

mysql -u root -p

Create DB user using the below statement

grant all privileges on *.* to ‘username’@‘%’ identified by ‘password’;

Open firewall:

sudo ufw allow 3306

Restart mysql

sudo service mysql restart

Python, remove all non-alphabet chars from string

Use re.sub

import re

regex = re.compile('[^a-zA-Z]')
#First parameter is the replacement, second parameter is your input string
regex.sub('', 'ab3d*E')
#Out: 'abdE'

Alternatively, if you only want to remove a certain set of characters (as an apostrophe might be okay in your input...)

regex = re.compile('[,\.!?]') #etc.

Which way is best for creating an object in JavaScript? Is `var` necessary before an object property?

Of course there is a best way.Objects in javascript have enumerable and nonenumerable properties.

var empty = {};
console.log(empty.toString);
// . function toString(){...}
console.log(empty.toString());
// . [object Object]

In the example above you can see that an empty object actually has properties.

Ok first let's see which is the best way:

var new_object = Object.create(null)

new_object.name = 'Roland'
new_object.last_name = 'Doda'
//etc

console.log("toString" in new_object) //=> false

In the example above the log will output false.

Now let's see why the other object creation ways are incorrect.

//Object constructor
var object = new Object();

console.log("toString" in object); //=> true

//Literal constructor
var person = { 
  name : "Anand",
  getName : function (){
   return this.name
  } 
} 

console.log("toString" in person); //=> true

//function Constructor
function Person(name){
  this.name = name
  this.getName = function(){
    return this.name
  } 
}

var person = new Person ('landi')

console.log("toString" in person); //=> true

//Prototype
function Person(){};

Person.prototype.name = "Anand";

console.log("toString" in person); //=> true

//Function/Prototype combination
function Person2(name){
  this.name = name;
} 

Person2.prototype.getName = function(){
  return this.name
}

var person2 = new Person2('Roland')

console.log("toString" in person2) //=> true

As you can see above,all examples log true.Which means if you have a case that you have a for in loop to see if the object has a property will lead you to wrong results probably.

Note that the best way it is not easy.You have to define all properties of object line by line.The other ways are more easier and will have less code to create an object but you have to be aware in some cases. I always use the "other ways" by the way and one solution to above warning if you don't use the best way is:

 for (var property in new_object) {
  if (new_object.hasOwnProperty(property)) {
    // ... this is an own property
  }
 }

How to run a SQL query on an Excel table?

I might be misunderstanding me, but isn't this exactly what a pivot table does? Do you have the data in a table or just a filtered list? If its not a table make it one (ctrl+l) if it is, then simply activate any cell in the table and insert a pivot table on another sheet. Then Add the columns lastname, firstname, phonenumber to the rows section. Then Add Phone number to the filter section and filter out the null values. Now Sort like normal.

Responsive iframe using Bootstrap

So, youtube gives out the iframe tag as follows:

<iframe width="560" height="315" src="https://www.youtube.com/embed/2EIeUlvHAiM" frameborder="0" allowfullscreen></iframe>

In my case, i just changed it to width="100%" and left the rest as is. It's not the most elegant solution (after all, in different devices you'll get weird ratios) But the video itself does not get deformed, just the frame.

R * not meaningful for factors ERROR

new[,2] is a factor, not a numeric vector. Transform it first

new$MY_NEW_COLUMN <-as.numeric(as.character(new[,2])) * 5

How to generate a number of most distinctive colors in R?

I would recomend to use an external source for large color palettes.

http://tools.medialab.sciences-po.fr/iwanthue/

has a service to compose any size of palette according to various parameters and

https://graphicdesign.stackexchange.com/questions/3682/where-can-i-find-a-large-palette-set-of-contrasting-colors-for-coloring-many-d/3815

discusses the generic problem from a graphics designers perspective and gives lots of examples of usable palettes.

To comprise a palette from RGB values you just have to copy the values in a vector as in e.g.:

colors37 = c("#466791","#60bf37","#953ada","#4fbe6c","#ce49d3","#a7b43d","#5a51dc","#d49f36","#552095","#507f2d","#db37aa","#84b67c","#a06fda","#df462a","#5b83db","#c76c2d","#4f49a3","#82702d","#dd6bbb","#334c22","#d83979","#55baad","#dc4555","#62aad3","#8c3025","#417d61","#862977","#bba672","#403367","#da8a6d","#a79cd4","#71482c","#c689d0","#6b2940","#d593a7","#895c8b","#bd5975")

SQL Server Group by Count of DateTime Per Hour?

You can also achieve this by using following SQL with date and hour in same columns and proper date time format and ordered by date time

SELECT  dateadd(hour, datediff(hour, 0, StartDate), 0) as 'ForDate', 
    COUNT(*) as 'Count' 
FROM #Events
GROUP BY dateadd(hour, datediff(hour, 0, LogTime), 0)
ORDER BY ForDate

PHP: Inserting Values from the Form into MySQL

There are two problems in your code.

  1. No action found in form.
  2. You have not executed the query mysqli_query()

dbConfig.php

<?php

$conn=mysqli_connect("localhost","root","password","testDB");

if(!$conn)
{
die("Connection failed: " . mysqli_connect_error());
}

?>

index.php

 include('dbConfig.php');

<!Doctype html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="description" content="$1">
<meta name="viewport" content="width=device-width, initial-scale=1">

<link rel="stylesheet" type="text/css" href="style.css">

<title>test</title>


</head>
<body>

 <?php

  if(isset($_POST['save']))
{
    $sql = "INSERT INTO users (username, password, email)
    VALUES ('".$_POST["username"]."','".$_POST["password"]."','".$_POST["email"]."')";

    $result = mysqli_query($conn,$sql);
}

?>

<form action="index.php" method="post"> 
<label id="first"> First name:</label><br/>
<input type="text" name="username"><br/>

<label id="first">Password</label><br/>
<input type="password" name="password"><br/>

<label id="first">Email</label><br/>
<input type="text" name="email"><br/>

<button type="submit" name="save">save</button>

</form>

</body>
</html>

Are strongly-typed functions as parameters possible in TypeScript?

In TS we can type functions in the in the following manners:

Functions types/signatures

This is used for real implementations of functions/methods it has the following syntax:

(arg1: Arg1type, arg2: Arg2type) : ReturnType

Example:

function add(x: number, y: number): number {
    return x + y;
}

class Date {
  setTime(time: number): number {
   // ...
  }

}

Function Type Literals

Function type literals are another way to declare the type of a function. They're usually applied in the function signature of a higher-order function. A higher-order function is a function which accepts functions as parameters or which returns a function. It has the following syntax:

(arg1: Arg1type, arg2: Arg2type) => ReturnType

Example:

type FunctionType1 = (x: string, y: number) => number;

class Foo {
    save(callback: (str: string) => void) {
       // ...
    }

    doStuff(callback: FunctionType1) {
       // ...
    }

}

ffprobe or avprobe not found. Please install one

Make sure you have the last version for youtube-dl

sudo youtube-dl -U

after that you can solve this problem by installing the missing ffmpeg on ubuntu and debian:

sudo apt-get install ffmpeg

and macOS use the command:

brew install ffmpeg

Twitter Bootstrap - how to center elements horizontally or vertically

From the Bootstrap documentation:

Set an element to display: block and center via margin. Available as a mixin and class.

<div class="center-block">...</div>

Refresh Excel VBA Function Results

Okay, found this one myself. You can use Ctrl+Alt+F9 to accomplish this.

Gradle proxy configuration

An update to @sourcesimian 's and @kunal-b's answer which dynamically sets the username and password if configured in the system properties.

The following sets the username and password if provided or just adds the host and port if no username and password is set.

task setHttpProxyFromEnv {
    def map = ['HTTP_PROXY': 'http', 'HTTPS_PROXY': 'https']
    for (e in System.getenv()) {
        def key = e.key.toUpperCase()
        if (key in map) {
            def base = map[key]
            //Get proxyHost,port, username, and password from http system properties 
            // in the format http://username:password@proxyhost:proxyport
            def (val1,val2) = e.value.tokenize( '@' )
            def (val3,val4) = val1.tokenize( '//' )
            def(userName, password) = val4.tokenize(':')
            def url = e.value.toURL()
            //println " - systemProp.${base}.proxy=${url.host}:${url.port}"
            System.setProperty("${base}.proxyHost", url.host.toString())
            System.setProperty("${base}.proxyPort", url.port.toString())
            System.setProperty("${base}.proxyUser", userName.toString())
            System.setProperty("${base}.proxyPassword", password.toString())
        }
    }
}

how to convert integer to string?

NSString* myNewString = [NSString stringWithFormat:@"%d", myInt];

Creating dummy variables in pandas for python

You can create dummy variables to handle the categorical data

# Creating dummy variables for categorical datatypes
trainDfDummies = pd.get_dummies(trainDf, columns=['Col1', 'Col2', 'Col3', 'Col4'])

This will drop the original columns in trainDf and append the column with dummy variables at the end of the trainDfDummies dataframe.

It automatically creates the column names by appending the values at the end of the original column name.

What is the best way to update the entity in JPA

Using executeUpdate() on the Query API is faster because it bypasses the persistent context .However , by-passing persistent context would cause the state of instance in the memory and the actual values of that record in the DB are not synchronized.

Consider the following example :

 Employee employee= (Employee)entityManager.find(Employee.class , 1);
 entityManager
     .createQuery("update Employee set name = \'xxxx\' where id=1")
     .executeUpdate();

After flushing, the name in the DB is updated to the new value but the employee instance in the memory still keeps the original value .You have to call entityManager.refresh(employee) to reload the updated name from the DB to the employee instance.It sounds strange if your codes still have to manipulate the employee instance after flushing but you forget to refresh() the employee instance as the employee instance still contains the original values.

Normally , executeUpdate() is used in the bulk update process as it is faster due to bypassing the persistent context

The right way to update an entity is that you just set the properties you want to updated through the setters and let the JPA to generate the update SQL for you during flushing instead of writing it manually.

   Employee employee= (Employee)entityManager.find(Employee.class ,1);
   employee.setName("Updated Name");

How do I check if a Key is pressed on C++

check if a key is pressed, if yes, then do stuff

Consider 'select()', if this (reportedly Posix) function is available on your os.

'select()' uses 3 sets of bits, which you create using functions provided (see man select, FD_SET, etc). You probably only need create the input bits (for now)


from man page:

'select()' "allow a program to monitor multiple file descriptors, waiting until one or more of the file descriptors become "ready" for some class of I/O operation (e.g., input possible). A file descriptor is considered ready if it is possible to perform a corresponding I/O operation (e.g., read(2) without blocking...)"

When select is invoked:

a) the function looks at each fd identified in the sets, and if that fd state indicates you can do something (perhaps read, perhaps write), select will return and let you go do that ... 'all you got to do' is scan the bits, find the set bit, and take action on the fd associated with that bit.

The 1st set (passed into select) contains active input fd's (typically devices). Probably 1 bit in this set is all you will need. And with only 1 fd (i.e. an input from keyboard), 1 bit, this is all quite simple. With this return from select, you can 'do-stuff' (perhaps, after you have fetched the char).

b) the function also has a timeout, with which you identify how much time to await a change of the fd state. If the fd state does not change, the timeout will cause 'select()' to return with a 0. (i.e. no keyboard input) Your code can do something at this time, too, perhaps an output.

fyi - fd's are typically 0,1,2... Remembe that C uses 0 as STDIN, 1 and STDOUT.


Simple test set up: I open a terminal (separate from my console), and type the tty command in that terminal to find its id. The response is typically something like "/dev/pts/0", or 3, or 17...

Then I get an fd to use in 'select()' by using open:

// flag options are: O_RDONLY, O_WRONLY, or O_RDWR
int inFD = open( "/dev/pts/5", O_RDONLY ); 

It is useful to cout this value.

Here is a snippet to consider (from man select):

  fd_set rfds;
  struct timeval tv;
  int retval;

  /* Watch stdin (fd 0) to see when it has input. */
  FD_ZERO(&rfds);
  FD_SET(0, &rfds);

  /* Wait up to five seconds. */
  tv.tv_sec = 5;
  tv.tv_usec = 0;

  retval = select(1, &rfds, NULL, NULL, &tv);
  /* Don't rely on the value of tv now! */

  if (retval == -1)
      perror("select()");
  else if (retval)
      printf("Data is available now.\n");  // i.e. doStuff()
      /* FD_ISSET(0, &rfds) will be true. */
  else
      printf("No data within five seconds.\n"); // i.e. key not pressed

How to capitalize the first letter of text in a TextView in an Android Application

For Kotlin, if you want to be sure that the format is "Aaaaaaaaa" you can use :

myString.toLowerCase(Locale.getDefault()).capitalize()

Makefile If-Then Else and Loops

Here's an example if:

ifeq ($(strip $(OS)),Linux)
        PYTHON = /usr/bin/python
        FIND = /usr/bin/find
endif

Note that this comes with a word of warning that different versions of Make have slightly different syntax, none of which seems to be documented very well.

How to search text using php if ($text contains "World")

  /* https://ideone.com/saBPIe */

  function search($search, $string) {

    $pos = strpos($string, $search);  

    if ($pos === false) {

      return "not found";     

    } else {

      return "found in " . $pos;

    }    

  }

  echo search("world", "hello world");

Embed PHP online:

_x000D_
_x000D_
body, html, iframe { _x000D_
  width: 100% ;_x000D_
  height: 100% ;_x000D_
  overflow: hidden ;_x000D_
}
_x000D_
<iframe src="https://ideone.com/saBPIe" ></iframe>
_x000D_
_x000D_
_x000D_

Visual Studio 2017 error: Unable to start program, An operation is not legal in the current state

I was able to solve this issue in Chrome by turning off the Calendly Chrome extension which I had recently installed. May not be Calendly specific so I would recommend turning off any newly installed Chrome extensions. Below are the steps I took:

  1. Debug Program
  2. Let Chrome Open and VS throw error
  3. Clear VS error by clicking OK
  4. Click Three dots in the top right corner of Chrome
  5. Mouse over "More Tools" and click Extensions
  6. Find Calendly tile and tick the slider in the bottom right corner to off position
  7. Close all Chrome windows including any Chrome windows in the task the bar that continue to run
  8. Stop debugging
  9. Run program again in debug mode

Inserting data into a temporary table

All the above mentioned answers will almost fullfill the purpose. However, You need to drop the temp table after all the operation on it. You can follow-

INSERT INTO #TempTable (ID, Date, Name) SELECT id, date, name FROM physical_table;

IF OBJECT_ID('tempdb.dbo.#TempTable') IS NOT NULL DROP TABLE #TempTable;

Restart pods when configmap updates in Kubernetes?

Another way is to stick it into the command section of the Deployment:

...
command: [ "echo", "
  option = value\n
  other_option = value\n
" ]
...

Alternatively, to make it more ConfigMap-like, use an additional Deployment that will just host that config in the command section and execute kubectl create on it while adding an unique 'version' to its name (like calculating a hash of the content) and modifying all the deployments that use that config:

...
command: [ "/usr/sbin/kubectl-apply-config.sh", "
  option = value\n
  other_option = value\n
" ]
...

I'll probably post kubectl-apply-config.sh if it ends up working.

(don't do that; it looks too bad)

How to change border color of textarea on :focus

you need just in scss varible

$input-btn-focus-width:       .05rem !default;

How do I configure IIS for URL Rewriting an AngularJS application in HTML5 mode?

I've been trying to deploy a simple Angular 7 application, to an Azure Web App. Everything worked fine, until the point where you refreshed the page. Doing so, was presenting me with an 500 error - moved content. I've read both on the Angular docs and in around a good few forums, that I need to add a web.config file to my deployed solution and make sure the rewrite rule fallback to the index.html file. After hours of frustration and trial and error tests, I've found the error was quite simple: adding a tag around my file markup.

How to Upload Image file in Retrofit 2

For those with an inputStream, you can upload inputStream using Multipart.

@Multipart
@POST("pictures")
suspend fun uploadPicture(
        @Part part: MultipartBody.Part
): NetworkPicture

Then in perhaps your repository class:

suspend fun upload(inputStream: InputStream) {
   val part = MultipartBody.Part.createFormData(
         "pic", "myPic", RequestBody.create(
              MediaType.parse("image/*"),
              inputStream.readBytes()
          )
   )
   uploadPicture(part)
}

To get an input stream you can do something like so.

In your fragment or activity, you need to create an image picker that returns an InputStream. The advantage of an InputStream is that it can be used for files on the cloud like google drive and dropbox.

Call pickImage() from a View.OnClickListener or onOptionsItemSelected.

    private fun pickImage() {
        val intent = Intent(Intent.ACTION_GET_CONTENT)
        intent.type = "image/*"
        startActivityForResult(intent, PICK_PHOTO)
    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        if (requestCode == PICK_PHOTO && resultCode == Activity.RESULT_OK) {
            try {
                data?.let {
                    val inputStream: InputStream? =
                        context?.contentResolver?.openInputStream(it.data!!)
                    inputStream?.let { stream ->
                        itemViewModel.uploadPicture(stream)
                    }
                }
            } catch (e: FileNotFoundException) {
                e.printStackTrace()
            }
        }
    }

    companion object {
        const val PICK_PHOTO = 1
    }

Restart android machine

I think the only way to do this is to run another machine in parallel and use that machine to issue commands to your android box similar to how you would with a phone. If you have issues with the IP changing you can reserve an ip on your router and have the machine grab that one instead of asking the routers DHCP for one. This way you can ping the machine and figure out if it's done rebooting to continue the script.

ExecuteNonQuery: Connection property has not been initialized.

You need to assign the connection to the SqlCommand, you can use the constructor or the property:

cmd.InsertCommand = new SqlCommand("INSERT INTO Application VALUES (@EventLog, @TimeGenerated, @EventType, @SourceName, @ComputerName, @InstanceId, @Message) ");
cmd.InsertCommand.Connection = connection1;

I strongly recommend to use the using-statement for any type implementing IDisposable like SqlConnection, it'll also close the connection:

using(var connection1 = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=syslog2;Integrated Security=True"))
using(var cmd = new SqlDataAdapter())
using(var insertCommand = new SqlCommand("INSERT INTO Application VALUES (@EventLog, @TimeGenerated, @EventType, @SourceName, @ComputerName, @InstanceId, @Message) "))
{
    insertCommand.Connection = connection1;
    cmd.InsertCommand = insertCommand;
    //.....
    connection1.Open();
    // .... you don't need to close the connection explicitely
}

Apart from that you don't need to create a new connection and DataAdapter for every entry in the foreach, even if creating, opening and closing a connection does not mean that ADO.NET will create, open and close a physical connection but just looks into the connection-pool for an available connection. Nevertheless it's an unnecessary overhead.

How can I use an ES6 import in Node.js?

If you are using the modules system on the server side, you do not need to use Babel at all. To use modules in Node.js ensure that:

  1. Use a version of node that supports the --experimental-modules flag
  2. Your *.js files must then be renamed to *.mjs

That's it.

However and this is a big however, while your shinny pure ES6 code will run in an environment like Node.js (e.g., 9.5.0) you will still have the craziness of transpilling just to test. Also bear in mind that Ecma has stated that release cycles for JavaScript are going to be faster, with newer features delivered on a more regular basis. Whilst this will be no problems for single environments like Node.js, it's a slightly different proposition for browser environments. What is clear is that testing frameworks have a lot to do in catching up. You will still need to probably transpile for testing frameworks. I'd suggest using Jest.

Also be aware of bundling frameworks. You will be running into problems there.

Which characters need to be escaped in HTML?

Basically, there are three main characters which should be always escaped in your HTML and XML files, so they don't interact with the rest of the markups, so as you probably expect, two of them gonna be the syntax wrappers, which are <>, they are listed as below:

 1)  &lt; (<)
    
 2)  &gt; (>)
    
 3)  &amp; (&)

Also we may use double-quote (") as " and the single quote (') as &apos

Avoid putting dynamic content in <script> and <style>.These rules are not for applied for them. For example, if you have to include JSON in a , replace < with \x3c, the U+2028 character with \u2028, and U+2029 with \u2029 after JSON serialisation.)

HTML Escape Characters: Complete List: http://www.theukwebdesigncompany.com/articles/entity-escape-characters.php

So you need to escape <, or & when followed by anything that could begin a character reference. Also The rule on ampersands is the only such rule for quoted attributes, as the matching quotation mark is the only thing that will terminate one. But if you don’t want to terminate the attribute value there, escape the quotation mark.

Changing to UTF-8 means re-saving your file:

Using the character encoding UTF-8 for your page means that you can avoid the need for most escapes and just work with characters. Note, however, that to change the encoding of your document, it is not enough to just change the encoding declaration at the top of the page or on the server. You need to re-save your document in that encoding. For help understanding how to do that with your application read Setting encoding in web authoring applications.

Invisible or ambiguous characters:

A particularly useful role for escapes is to represent characters that are invisible or ambiguous in presentation.

One example would be Unicode character U+200F RIGHT-TO-LEFT MARK. This character can be used to clarify directionality in bidirectional text (eg. when using the Arabic or Hebrew scripts). It has no graphic form, however, so it is difficult to see where these characters are in the text, and if they are lost or forgotten they could create unexpected results during later editing. Using ? (or its numeric character reference equivalent ?) instead makes it very easy to spot these characters.

An example of an ambiguous character is U+00A0 NO-BREAK SPACE. This type of space prevents line breaking, but it looks just like any other space when used as a character. Using   makes it quite clear where such spaces appear in the text.

Access a URL and read Data with R

Often data on webpages is in the form of an XML table. You can read an XML table into R using the package XML.

In this package, the function

readHTMLTable(<url>)

will look through a page for XML tables and return a list of data frames (one for each table found).

What is the difference between baud rate and bit rate?

This topic is confusing because there are 3 terms in use when people think there are just 2, namely:

"bit rate": units are bits per second

"baud": units are symbols per second

"Baud rate": units are bits per second

"Baud rate" is really a marketing term rather than an engineering term. "Baud rate" was used by modem manufactures in a similar way to megapixels is used for digital cameras. So the higher the "Baud rate" the better the modem was perceived to be.

The engineering unit "baud" is already a rate (symbols per second) which distinguishes it from the "Baud rate" term. However, you can see from the answers that people are confusing these 2 terms together such as baud/sec which is wrong.

From an engineering point of view, I recommend people use the term "bit rate" for "RS-232" and consign to history the term "Baud rate". Use the term "baud" for modulation schemes but avoid it for "RS-232".

In other words, "bit rate" and "Baud rate" are the same thing which means how many bits are transmitted along a wire in one second. Note that bits per second (bps) is the low-level line rate and not the information data rate because asynchronous "RS-232" has start and stop bits that frame the 8 data bits of information so bps includes all bits transmitted.

Can HTML checkboxes be set to readonly?

Try this to make the checkbox read-only and yet disallow user from checking. This will let you POST the checkbox value. You need to select the default state of the checkbox as Checked in order to do so.

<input type="checkbox" readonly="readonly" onclick="this.checked =! this.checked;">

If you want the above functionality + dont want to receive the checkbox data, try the below:

<input type="checkbox" readonly="readonly" disabled="disabled" onclick="this.checked =! this.checked;">

Hope that helps.

Default string initialization: NULL or Empty?

I think there's no reason not to use null for an unassigned (or at this place in a program flow not occurring) value. If you want to distinguish, there's ==null. If you just want to check for a certain value and don't care whether it's null or something different, String.Equals("XXX",MyStringVar) does just fine.

How to get the sizes of the tables of a MySQL database?

There is an easy way to get many informations using Workbench:

  • Right-click the schema name and click "Schema inspector".

  • In the resulting window you have a number of tabs. The first tab "Info" shows a rough estimate of the database size in MB.

  • The second tab, "Tables", shows Data length and other details for each table.

Convert boolean to int in Java

public static int convBool(boolean b)
{
int convBool = 0;
if(b) convBool = 1;
return convBool;
}

Then use :

convBool(aBool);

MongoDb shuts down with Code 100

In my case, I got a similar error and it was happening because I had run mongod with the root user and that had created a log file only accessible by the root. I could fix this by changing the ownership from root to the user you normally run mongod from. The log file was in /var/lib/mongodb/journal/

Location of Django logs and errors

Logs are set in your settings.py file. A new, default project, looks like this:

# A sample logging configuration. The only tangible logging
# performed by this configuration is to send an email to
# the site admins on every HTTP 500 error when DEBUG=False.
# See http://docs.djangoproject.com/en/dev/topics/logging for
# more details on how to customize your logging configuration.
LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'filters': {
        'require_debug_false': {
            '()': 'django.utils.log.RequireDebugFalse'
        }
    },
    'handlers': {
        'mail_admins': {
            'level': 'ERROR',
            'filters': ['require_debug_false'],
            'class': 'django.utils.log.AdminEmailHandler'
        }
    },
    'loggers': {
        'django.request': {
            'handlers': ['mail_admins'],
            'level': 'ERROR',
            'propagate': True,
        },
    }
}

By default, these don't create log files. If you want those, you need to add a filename parameter to your handlers

    'applogfile': {
        'level':'DEBUG',
        'class':'logging.handlers.RotatingFileHandler',
        'filename': os.path.join(DJANGO_ROOT, 'APPNAME.log'),
        'maxBytes': 1024*1024*15, # 15MB
        'backupCount': 10,
    },

This will set up a rotating log that can get 15 MB in size and keep 10 historical versions.

In the loggers section from above, you need to add applogfile to the handlers for your application

'loggers': {
        'django.request': {
            'handlers': ['mail_admins'],
            'level': 'ERROR',
            'propagate': True,
        },
        'APPNAME': {
            'handlers': ['applogfile',],
            'level': 'DEBUG',
        },
    }

This example will put your logs in your Django root in a file named APPNAME.log

Add some word to all or some rows in Excel?

Following Mike's answer, I'd also add another step. Let's imagine you have your data in column A.

  • Insert a column with the word you want to add (column B, with k)
  • apply the formula (as suggested by Mike) that merges both values in column C (C1=A1+B1)
  • Copy down the formula
  • Copy the values in column C (already merged)
  • Paste special as 'values'
  • Remove columns A and B

Hope it helps.

Ofc, if the word you want to add will always be the same, you won't need a column B (thus, C1="k"+A1)

Rgds

How to efficiently remove duplicates from an array without using Set

class Demo 
{
    public static void main(String[] args) 
    {
        int a[]={3,2,1,4,2,1};
        System.out.print("Before Sorting:");
        for (int i=0;i<a.length; i++ )
        {
            System.out.print(a[i]+"\t");
        }
        System.out.print ("\nAfter Sorting:");
        //sorting the elements
        for(int i=0;i<a.length;i++)
        {
            for(int j=i;j<a.length;j++)
            {
                if(a[i]>a[j])
                {
                    int temp=a[i];
                    a[i]=a[j];
                    a[j]=temp;
                }

            }
        }

        //After sorting
        for(int i=0;i<a.length;i++)
        {
            System.out.print(a[i]+"\t");
        }
        System.out.print("\nAfter removing duplicates:");
        int b=0;
        a[b]=a[0];
        for(int i=0;i<a.length;i++)
        {
            if (a[b]!=a[i])
            {
                b++;
                a[b]=a[i];
            }
        }
        for (int i=0;i<=b;i++ )
        {
            System.out.print(a[i]+"\t");
        }
    }
}
  OUTPUT:Before Sortng:3 2 1 4 2 1 After Sorting:1 1 2 2 3 4 
                Removing Duplicates:1 2 3 4

Saving results with headers in Sql Server Management Studio

Try the Export Wizard. In this example I select a whole table, but you can just as easily specify a query:

enter image description here

enter image description here

enter image description here

enter image description here

(you can also specify a query here)

enter image description here

enter image description here

enter image description here

enter image description here

enter image description here

How to convert vector to array

If you have a function, then you probably need this:foo(&array[0], array.size());. If you managed to get into a situation where you need an array then you need to refactor, vectors are basically extended arrays, you should always use them.

Install NuGet via PowerShell script

This also seems to do it. PS Example:

Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force

What tool to use to draw file tree diagram

Copying and pasting from the MS-DOS tree command might also work for you. Examples:

tree

C:\Foobar>tree
C:.
+---FooScripts
+---barconfig
+---Baz
¦   +---BadBaz
¦   +---Drop
...

tree /F

C:\Foobar>tree
C:.
+---FooScripts
¦    foo.sh
+---barconfig
¦    bar.xml
+---Baz
¦   +---BadBaz
¦   ¦    badbaz.xml
¦   +---Drop
...

tree /A

C:\Foobar>tree /A
C:.
+---FooScripts
+---barconfig
+---Baz
¦   +---BadBaz
¦   \---Drop
...

tree /F /A

C:\Foobar>tree /A
C:.
+---FooScripts
¦    foo.sh
+---barconfig
¦    bar.xml
+---Baz
¦   +---BadBaz
¦   ¦    badbaz.xml
¦   \---Drop
...

Syntax [source]

tree [drive:][path] [/F] [/A]

drive:\path — Drive and directory containing disk for display of directory structure, without listing files.

/F — Include all files living in every directory.

/A — Replace graphic characters used for linking lines with ext characters , instead of graphic characters. /a is used with code pages that do not support graphic characters and to send output to printers that do not properly interpret graphic characters.

Trigger change event <select> using jquery

If you want to do some checks then use this way

 <select size="1" name="links" onchange="functionToTriggerClick(this.value)">
    <option value="">Select a Search Engine</option>        
    <option value="http://www.google.com">Google</option>
    <option value="http://www.yahoo.com">Yahoo</option>
</select>

<script>

   function functionToTriggerClick(link) {

     if(link != ''){
        window.location.href=link;
        }
    }  

</script>

C# compiler error: "not all code paths return a value"

I like to beat dead horses, but I just wanted to make an additional point:

First of all, the problem is that not all conditions of your control structure have been addressed. Essentially, you're saying if a, then this, else if b, then this. End. But what if neither? There's no way to exit (i.e. not every 'path' returns a value).

My additional point is that this is an example of why you should aim for a single exit if possible. In this example you would do something like this:

bool result = false;
if(conditionA)
{
   DoThings();
   result = true;
}
else if(conditionB)
{
   result = false;
}
else if(conditionC)
{
   DoThings();
   result = true;
}

return result;

So here, you will always have a return statement and the method always exits in one place. A couple things to consider though... you need to make sure that your exit value is valid on every path or at least acceptable. For example, this decision structure only accounts for three possibilities but the single exit can also act as your final else statement. Or does it? You need to make sure that the final return value is valid on all paths. This is a much better way to approach it versus having 50 million exit points.

How to set margin of ImageView using code, not xml

If you want to change imageview margin but leave all other margins intact.

  1. Get MarginLayoutParameters of your image view in this case: myImageView

     MarginLayoutParams marginParams = (MarginLayoutParams) myImageView.getLayoutParams();
    
  2. Now just change the margin you want to change but leave the others as they are:

     marginParams.setMargins(marginParams.leftMargin, 
                             marginParams.topMargin, 
                             150, //notice only changing right margin
                             marginParams.bottomMargin); 
    

The total number of locks exceeds the lock table size

Fixing Error code 1206: The number of locks exceeds the lock table size.

In my case, I work with MySQL Workbench (5.6.17) running on Windows with WampServer 2.5.

For Windows/WampServer you have to edit the my.ini file (not the my.cnf file)

To locate this file go to Menu Server/Server Status (in MySQL Workbench) and look under Server Directories/ Base Directory

MySQL Server - Server Status

In my.ini file there are defined sections for different settings, look for section [mysqld] (create it if it does not exist) and add the command: innodb_buffer_pool_size=4G

[mysqld]
innodb_buffer_pool_size=4G

The size of the buffer_pool file will depend on your specific machine, in most cases, 2G or 4G will fix the problem.

Remember to restart the server so it takes the new configuration, it corrected the problem for me.

Hope it helps!

What's in an Eclipse .classpath/.project file?

Complete reference is not available for the mentioned files, as they are extensible by various plug-ins.

Basically, .project files store project-settings, such as builder and project nature settings, while .classpath files define the classpath to use during running. The classpath files contains src and target entries that correspond with folders in the project; the con entries are used to describe some kind of "virtual" entries, such as the JVM libs or in case of eclipse plug-ins dependencies (normal Java project dependencies are displayed differently, using a special src entry).

How to change the bootstrap primary color?

This is a very easy solution.

<h4 class="card-header bg-dark text-white text-center">Renew your Membership</h4>

replace the class bg-dark, with bg-custom.

In CSS

.bg-custom {
  background-color: red;
}

Comparing HTTP and FTP for transferring files

Both of them uses TCP as a transport protocol, but HTTP uses a persistent connection, which makes the performance of the TCP better.

How to display HTML <FORM> as inline element?

Move your form tag just outside the paragraph and set margins / padding to zero:

<form style="margin: 0; padding: 0;">
  <p>
    Read this sentence 
    <input style="display: inline;" type="submit" value="or push this button" />
  </p>
</form>

Check if url contains string with JQuery

window.location is an object, not a string so you need to use window.location.href to get the actual string url

if (window.location.href.indexOf("?added-to-cart=555") >= 0) {
    alert("found it");
}

How to remove border of drop down list : CSS

You could simply use:

select {
    border: none;
    outline: none;
    scroll-behavior: smooth;
}

As the drop down list border is non editable you can not do anything with that but surely this will fix your initial outlook.

How to access single elements in a table in R

?"[" pretty much covers the various ways of accessing elements of things.

Under usage it lists these:

x[i]
x[i, j, ... , drop = TRUE]
x[[i, exact = TRUE]]
x[[i, j, ..., exact = TRUE]]
x$name
getElement(object, name)

x[i] <- value
x[i, j, ...] <- value
x[[i]] <- value
x$i <- value

The second item is sufficient for your purpose

Under Arguments it points out that with [ the arguments i and j can be numeric, character or logical

So these work:

data[1,1]
data[1,"V1"]

As does this:

data$V1[1]

and keeping in mind a data frame is a list of vectors:

data[[1]][1]
data[["V1"]][1]

will also both work.

So that's a few things to be going on with. I suggest you type in the examples at the bottom of the help page one line at a time (yes, actually type the whole thing in one line at a time and see what they all do, you'll pick up stuff very quickly and the typing rather than copypasting is an important part of helping to commit it to memory.)

Add shadow to custom shape on Android

9 patch to the rescue, nice shadow could be achieved easily especially with this awesome tool -

Android 9-patch shadow generator

PS: if project won't be able to compile you will need to move black lines in android studio editor a little bit

Can I scale a div's height proportionally to its width using CSS?

For anyone looking for a scalable solution: I wrote a small helper utility in SASS to generate responsive proportional rectangles for different breakpoints. Take a look at SASS Proportions

Hope it helps anybody!

Accessing Objects in JSON Array (JavaScript)

Use a loop

for(var i = 0; i < obj.length; ++i){
   //do something with obj[i]
   for(var ind in obj[i]) {
        console.log(ind);
        for(var vals in obj[i][ind]){
            console.log(vals, obj[i][ind][vals]);
        }
   }
}

Demo: http://jsfiddle.net/maniator/pngmL/

How to use lifecycle method getDerivedStateFromProps as opposed to componentWillReceiveProps

About the removal of componentWillReceiveProps: you should be able to handle its uses with a combination of getDerivedStateFromProps and componentDidUpdate, see the React blog post for example migrations. And yes, the object returned by getDerivedStateFromProps updates the state similarly to an object passed to setState.

In case you really need the old value of a prop, you can always cache it in your state with something like this:

state = {
  cachedSomeProp: null
  // ... rest of initial state
};

static getDerivedStateFromProps(nextProps, prevState) {
  // do things with nextProps.someProp and prevState.cachedSomeProp
  return {
    cachedSomeProp: nextProps.someProp,
    // ... other derived state properties
  };
}

Anything that doesn't affect the state can be put in componentDidUpdate, and there's even a getSnapshotBeforeUpdate for very low-level stuff.

UPDATE: To get a feel for the new (and old) lifecycle methods, the react-lifecycle-visualizer package may be helpful.

Exporting data In SQL Server as INSERT INTO

for SQl server Mng Studio 2016:

enter image description here

X close button only using css

True CSS with proper semantic and accessibility settings.

It is a <button>, It has text for screen readers.

https://codepen.io/specialweb/pen/ExyWPYv?editors=1100

_x000D_
_x000D_
button {
  width: 2rem;
  height: 2rem;
  padding: 0;
  position: absolute;
  top: 1rem;
  right: 1rem;
  cursor: pointer;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

button::before,
button::after {
    content: '';
    width: 1px;
    height: 100%;
    background: #333;
    display: block;
    transform: rotate(45deg) translateX(0px);
    position: absolute;
    left: 50%;
    top: 0;
}

button::after {
    transform: rotate(-45deg) translateX(0px);
}


/* demo */
body {
  background: black;
}
.pane {
  margin: 0 auto;
  width: 50vw;
  min-height: 50vh;
  background: #FFF;
  position: relative;
  border-radius: 5px;
}
_x000D_
<div class="pane">
  <button type="button"><span class="sr-only">Close</span></button>
</div>
_x000D_
_x000D_
_x000D_

Query comparing dates in SQL

Try to use "#" before and after of the date and be sure of your system date format. maybe "YYYYMMDD O YYYY-MM-DD O MM-DD-YYYY O USING '/ O \' "

Ex:

 select id,numbers_from,created_date,amount_numbers,SMS_text 
 from Test_Table
 where 
 created_date <= #2013-04-12#

Open Form2 from Form1, close Form1 from Form2

if you just want to close form1 from form2 without closing form2 as well in the process, as the title suggests, then you could pass a reference to form 1 along to form 2 when you create it and use that to close form 1

for example you could add a

public class Form2 : Form
{
    Form2(Form1 parentForm):base()
    {
        this.parentForm = parentForm;
    }

    Form1 parentForm;
    .....
}

field and constructor to Form2

if you want to first close form2 and then form1 as the text of the question suggests, I'd go with Justins answer of returning an appropriate result to form1 on upon closing form2

Understanding the ngRepeat 'track by' expression

If you are working with objects track by the identifier(e.g. $index) instead of the whole object and you reload your data later, ngRepeat will not rebuild the DOM elements for items it has already rendered, even if the JavaScript objects in the collection have been substituted for new ones.

Razor-based view doesn't see referenced assemblies

Your Project FOLDER name needs to be the same. If your Project or Solution name is different, then MVC will hurt you.

Example : If you create a new Application and it gets the default name Webapplicaiton1, then this namespace will be created. So, let us say that you dont want to have this namespace, so from the VS you change everywhere you can see to "MyNamespace". You also search and replace all code from "Webapplication1" and replace it with "MyNamespace". This also changes web.config file, so that it inculdes

Now everything will work, except Razor views.

RazorViews cannot find it, because there is some kind of strange dependency on the FOLDERNAME of the project. It is terrible design.

I have tested this semi-thoroughly by copying my files into a new solution, and the only difference being the foldername.

How to make HTTP Post request with JSON body in Swift

SWIFT 5 People Here :

let json: [String: Any] = ["key": "value"]

        let jsonData = try? JSONSerialization.data(withJSONObject: json)

        // create post request
        let url = URL(string: "http://localhost:1337/postrequest/addData")! //PUT Your URL
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("\(String(describing: jsonData?.count))", forHTTPHeaderField: "Content-Length")
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        // insert json data to the request
        request.httpBody = jsonData

        let task = URLSession.shared.dataTask(with: request) { data, response, error in
            guard let data = data, error == nil else {
                print(error?.localizedDescription ?? "No data")
                return
            }
            let responseJSON = try? JSONSerialization.jsonObject(with: data, options: [])
            if let responseJSON = responseJSON as? [String: Any] {
                print(responseJSON) //Code after Successfull POST Request
            }
        }

        task.resume()

ImportError: No module named google.protobuf

Had the same issue and I resolved it by using :

conda install protobuf

Getting a union of two arrays in JavaScript

Adapted from: https://stackoverflow.com/a/4026828/1830259

Array.prototype.union = function(a) 
{
    var r = this.slice(0);
    a.forEach(function(i) { if (r.indexOf(i) < 0) r.push(i); });
    return r;
};

Array.prototype.diff = function(a)
{
    return this.filter(function(i) {return a.indexOf(i) < 0;});
};

var s1 = [1, 2, 3, 4];
var s2 = [3, 4, 5, 6];

console.log("s1: " + s1);
console.log("s2: " + s2);
console.log("s1.union(s2): " + s1.union(s2));
console.log("s2.union(s1): " + s2.union(s1));
console.log("s1.diff(s2): " + s1.diff(s2));
console.log("s2.diff(s1): " + s2.diff(s1));

// Output:
// s1: 1,2,3,4
// s2: 3,4,5,6
// s1.union(s2): 1,2,3,4,5,6
// s2.union(s1): 3,4,5,6,1,2
// s1.diff(s2): 1,2
// s2.diff(s1): 5,6 

100% width table overflowing div container

Try adding

word-break: break-all 

to the CSS on your table element.

That will get the words in the table cells to break such that the table does not grow wider than its containing div, yet the table columns are still sized dynamically. jsfiddle demo.

Django - taking values from POST request

Read about request objects that your views receive: https://docs.djangoproject.com/en/dev/ref/request-response/#httprequest-objects

Also your hidden field needs a reliable name and then a value:

<input type="hidden" name="title" value="{{ source.title }}">

Then in a view:

request.POST.get("title", "")

Copying files from server to local computer using SSH

It depends on what your local OS is.

If your local OS is Unix-like, then try:

scp username@remoteHost:/remote/dir/file.txt /local/dir/

If your local OS is Windows ,then you should use pscp.exe utility. For example, below command will download file.txt from remote to D: disk of local machine.

pscp.exe username@remoteHost:/remote/dir/file.txt d:\

It seems your Local OS is Unix, so try the former one.


For those who don't know what pscp.exe is and don't know where it is, you can always go to putty official website to download it. And then open a CMD prompt, go to the pscp.exe directory where you put it. Then execute the command as provided above

How do you append to an already existing string?

teststr=$'test1\n'
teststr+=$'test2\n'
echo "$teststr"

"Insert if not exists" statement in SQLite

For a unique column, use this:

INSERT OR REPLACE INTO table () values();

For more information, see: sqlite.org/lang_insert

Using `date` command to get previous, current and next month

the main problem occur when you don't have date --date option available and you don't have permission to install it, then try below -

Previous month
#cal -3|awk 'NR==1{print toupper(substr($1,1,3))"-"$2}'
DEC-2016 
Current month
#cal -3|awk 'NR==1{print toupper(substr($3,1,3))"-"$4}'
JAN-2017
Next month
#cal -3|awk 'NR==1{print toupper(substr($5,1,3))"-"$6}'
FEB-2017

Why am I getting this error: No mapping specified for the following EntitySet/AssociationSet - Entity1?

I found I was getting the same error because I had forgot to create referential constraint after creating an association between two entities.

How can I check if my python object is a number?

That's not really how python works. Just use it like you would a number, and if someone passes you something that's not a number, fail. It's the programmer's responsibility to pass in the correct types.

SQL permissions for roles

USE DataBaseName; GO --------- CREATE ROLE --------- CREATE ROLE Doctors ; GO  ---- Assign Role To users -------  CREATE USER [Username] FOR LOGIN [Domain\Username] EXEC sp_addrolemember N'Doctors', N'Username'  ----- GRANT Permission to Users Assinged with this Role----- GRANT ALL ON Table1, Table2, Table3 TO Doctors; GO 

Excel how to fill all selected blank cells with text

OK, what you can try is

Cntrl+H (Find and Replace), leave Find What blank and change Replace With to NULL.

That should replace all blank cells in the USED range with NULL

Add a column in a table in HIVE QL

You cannot add a column with a default value in Hive. You have the right syntax for adding the column ALTER TABLE test1 ADD COLUMNS (access_count1 int);, you just need to get rid of default sum(max_count). No changes to that files backing your table will happen as a result of adding the column. Hive handles the "missing" data by interpreting NULL as the value for every cell in that column.

So now your have the problem of needing to populate the column. Unfortunately in Hive you essentially need to rewrite the whole table, this time with the column populated. It may be easier to rerun your original query with the new column. Or you could add the column to the table you have now, then select all of its columns plus value for the new column.

You also have the option to always COALESCE the column to your desired default and leave it NULL for now. This option fails when you want NULL to have a meaning distinct from your desired default. It also requires you to depend on always remembering to COALESCE.

If you are very confident in your abilities to deal with the files backing Hive, you could also directly alter them to add your default. In general I would recommend against this because most of the time it will be slower and more dangerous. There might be some case where it makes sense though, so I've included this option for completeness.

How to correct TypeError: Unicode-objects must be encoded before hashing?

The error already says what you have to do. MD5 operates on bytes, so you have to encode Unicode string into bytes, e.g. with line.encode('utf-8').

how to cancel/abort ajax request in axios

import React, { Component } from "react";
import axios from "axios";

const CancelToken = axios.CancelToken;

let cancel;

class Abc extends Component {
  componentDidMount() {
    this.Api();
  }

  Api() {
      // Cancel previous request
    if (cancel !== undefined) {
      cancel();
    }
    axios.post(URL, reqBody, {
        cancelToken: new CancelToken(function executor(c) {
          cancel = c;
        }),
      })
      .then((response) => {
        //responce Body
      })
      .catch((error) => {
        if (axios.isCancel(error)) {
          console.log("post Request canceled");
        }
      });
  }

  render() {
    return <h2>cancel Axios Request</h2>;
  }
}

export default Abc;

What is the most efficient way to check if a value exists in a NumPy array?

The most convenient way according to me is:

(Val in X[:, col_num])

where Val is the value that you want to check for and X is the array. In your example, suppose you want to check if the value 8 exists in your the third column. Simply write

(8 in X[:, 2])

This will return True if 8 is there in the third column, else False.

Checking for an empty file in C++

Ok, so this piece of code should work for you. I changed the names to match your parameter.

inFile.seekg(0, ios::end);  
if (inFile.tellg() == 0) {    
  // ...do something with empty file...  
}

Hibernate Criteria Query to get specific columns

You can map another entity based on this class (you should use entity-name in order to distinct the two) and the second one will be kind of dto (dont forget that dto has design issues ). you should define the second one as readonly and give it a good name in order to be clear that this is not a regular entity. by the way select only few columns is called projection , so google with it will be easier.

alternative - you can create named query with the list of fields that you need (you put them in the select ) or use criteria with projection

Why use $_SERVER['PHP_SELF'] instead of ""

Using an empty string is perfectly fine and actually much safer than simply using $_SERVER['PHP_SELF'].

When using $_SERVER['PHP_SELF'] it is very easy to inject malicious data by simply appending /<script>... after the whatever.php part of the URL so you should not use this method and stop using any PHP tutorial that suggests it.

Inline for loop

q  = [1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5]
vm = [-1, -1, -1, -1,1,2,3,1]

p = []
for v in vm:
    if v in q:
        p.append(q.index(v))
    else:
        p.append(99999)

print p
p = [q.index(v) if v in q else 99999 for v in vm]
print p

Output:

[99999, 99999, 99999, 99999, 0, 1, 2, 0]
[99999, 99999, 99999, 99999, 0, 1, 2, 0]

Instead of using append() in the list comprehension you can reference the p as direct output, and use q.index(v) and 99999 in the LC.

Not sure if this is intentional but note that q.index(v) will find just the first occurrence of v, even tho you have several in q. If you want to get the index of all v in q, consider using a enumerator and a list of already visited indexes

Something in those lines(pseudo-code):

visited = []
for i, v in enumerator(vm):
   if i not in visited:
       p.append(q.index(v))
   else:
       p.append(q.index(v,max(visited))) # this line should only check for v in q after the index of max(visited)
   visited.append(i)

Setting Custom ActionBar Title from Fragment

A simple Kotlin example

Assuming these gradle deps match or are higher version in your project:

kotlin_version = '1.3.41'
nav_version_ktx = '2.0.0'

Adapt this to your fragment classes:

    /**
     * A simple [Fragment] subclass.
     *
     * Updates the action bar title when onResume() is called on the fragment,
     * which is called every time you navigate to the fragment
     *
     */

    class MyFragment : Fragment() {
    private lateinit var mainActivity: MainActivity

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {

       //[...]

        mainActivity = this.activity as MainActivity

       //[...]
    }

    override fun onResume() {
        super.onResume()
        mainActivity.supportActionBar?.title = "My Fragment!"
    }


    }

How to send an email using PHP?

using PHP built in function mail()

more info from : https://www.php.net/manual/en/function.mail.php

How to initialize an array's length in JavaScript?

  1. Why do you want to initialize the length? Theoretically there is no need for this. It can even result in confusing behavior, because all tests that use the length to find out whether an array is empty or not will report that the array is not empty.
    Some tests show that setting the initial length of large arrays can be more efficient if the array is filled afterwards, but the performance gain (if any) seem to differ from browser to browser.

  2. jsLint does not like new Array() because the constructer is ambiguous.

    new Array(4);
    

    creates an empty array of length 4. But

    new Array('4');
    

    creates an array containing the value '4'.

Regarding your comment: In JS you don't need to initialize the length of the array. It grows dynamically. You can just store the length in some variable, e.g.

var data = [];
var length = 5; // user defined length

for(var i = 0; i < length; i++) {
    data.push(createSomeObject());
}

Number prime test in JavaScript

One of the shortest version

isPrime=(n)=>[...Array(n-2)].map((_,i)=>i+2).filter(i=>n%i==0).length==0

Where are static variables stored in C and C++?

they're both going to be stored independently, however if you want to make it clear to other developers you might want to wrap them up in namespaces.

Regex: Remove lines containing "help", etc

If you're on Windows, try findstr. Third-party tools are not needed:

findstr /V /L "searchstring" inputfile.txt > outputfile.txt

It supports regex's too! Just read the tool's help findstr /?.

P.S. If you want to work with big, huge files (like 400 MB log files) a text editor is not very memory-efficient, so, as someone already pointed out, command-line tools are the way to go. But there's no grep on Windows, so...

I just ran this on a 1 GB log file, and it literally took 3 seconds.

How to disable sort in DataGridView?

If you can extend the DataGridView you can override the Sort method with am empty one. This disables Sort for the DataGridView entirely.

public override void Sort(DataGridViewColumn dataGridViewColumn, ListSortDirection direction)
{
    //base.Sort(dataGridViewColumn, direction);
}

Note: You cannot even programmatically sort any column.

Extract number from string with Oracle function

You'd use REGEXP_REPLACE in order to remove all non-digit characters from a string:

select regexp_replace(column_name, '[^0-9]', '')
from mytable;

or

select regexp_replace(column_name, '[^[:digit:]]', '')
from mytable;

Of course you can write a function extract_number. It seems a bit like overkill though, to write a funtion that consists of only one function call itself.

create function extract_number(in_number varchar2) return varchar2 is
begin
  return regexp_replace(in_number, '[^[:digit:]]', '');
end; 

How to Migrate to WKWebView?

UIWebView will still continue to work with existing apps. WKWebView is available starting from iOS8, only WKWebView has a Nitro JavaScript engine.

To take advantage of this faster JavaScript engine in older apps you have to make code changes to use WKWebView instead of UIWebView. For iOS7 and older, you have to continue to use UIWebView, so you may have to check for iOS8 and then apply WKWebView methods / delegate methods and fallback to UIWebView methods for iOS7 and older. Also there is no Interface Builder component for WKWebView (yet), so you have to programmatically implement WKWebView.

You can implement WKWebView in Objective-C, here is simple example to initiate a WKWebView:

WKWebViewConfiguration *theConfiguration = [[WKWebViewConfiguration alloc] init];
WKWebView *webView = [[WKWebView alloc] initWithFrame:self.view.frame configuration:theConfiguration];
webView.navigationDelegate = self;
NSURL *nsurl=[NSURL URLWithString:@"http://www.apple.com"];
NSURLRequest *nsrequest=[NSURLRequest requestWithURL:nsurl];
[webView loadRequest:nsrequest];
[self.view addSubview:webView];

WKWebView rendering performance is noticeable in WebGL games and something that runs complex JavaScript algorithms, if you are using webview to load a simple html or website, you can continue to use UIWebView.

Here is a test app that can used to open any website using either UIWebView or WKWebView and you can compare performance, and then decide on upgrading your app to use WKWebView: https://itunes.apple.com/app/id928647773?mt=8&at=10ltWQ

enter image description here

android edittext onchange listener

The Watcher method fires on every character input. So, I built this code based on onFocusChange method:

public static boolean comS(String s1,String s2){
    if (s1.length()==s2.length()){
        int l=s1.length();
        for (int i=0;i<l;i++){
            if (s1.charAt(i)!=s2.charAt(i))return false;
        }
        return true;
    }
    return false;
}

public void onChange(final EditText EdTe, final Runnable FRun){
    class finalS{String s="";}
    final finalS dat=new finalS();  
    EdTe.setOnFocusChangeListener(new OnFocusChangeListener() {          
        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if (hasFocus) {dat.s=""+EdTe.getText();}
            else if (!comS(dat.s,""+EdTe.getText())){(new Handler()).post(FRun);}       
        }
    });
}

To using it, just call like this:

onChange(YourEditText, new Runnable(){public void run(){
    // V  V    YOUR WORK HERE

    }}
);

You can ignore the comS function by replace the !comS(dat.s,""+EdTe.getText()) with !equal function. However the equal function itself some time work not correctly in run time.

The onChange listener will remember old data of EditText when user focus typing, and then compare the new data when user lose focus or jump to other input. If comparing old String not same new String, it fires the work.

If you only have 1 EditText, then u will need to make a ClearFocus function by making an Ultimate Secret Transparent Micro EditText outside the windows and request focus to it, then hide the keyboard via Import Method Manager.

What are OLTP and OLAP. What is the difference between them?

OLTP: It stands for OnLine Transaction Processing and is used for managing current day to day data information.
OLAP: It stands for OnLine Analytical Processing and is used to maintain the past history of data and mainly used for data analysis, it can also be referred to as warehouse.

How to use nan and inf in C?

A compiler independent way, but not processor independent way to get these:

int inf = 0x7F800000;
return *(float*)&inf;

int nan = 0x7F800001;
return *(float*)&nan;

This should work on any processor which uses the IEEE 754 floating point format (which x86 does).

UPDATE: Tested and updated.

Changing background colour of tr element on mouseover

tr:hover td.someclass {
   background: #EDB01C;
   color:#FFF;
}

only someclass cell highlight

Chrome not rendering SVG referenced via <img> tag

Use <object> instead (of course, replace each URL with your own):

_x000D_
_x000D_
.BackgroundImage {_x000D_
        background: url('https://upload.wikimedia.org/wikipedia/commons/b/bd/Test.svg') no-repeat scroll left top;_x000D_
        width: 400px;_x000D_
        height: 600px;_x000D_
}
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
    <title>SVG Test</title>_x000D_
</head>_x000D_
<body>_x000D_
    <div id="ObjectTag">_x000D_
        <object type="image/svg+xml" data="https://upload.wikimedia.org/wikipedia/commons/b/bd/Test.svg" width="400" height="600">_x000D_
          Your browser does not support SVG._x000D_
        </object>_x000D_
    </div>_x000D_
    <div class="BackgroundImage"></div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Storing money in a decimal column - what precision and scale?

If you were using IBM Informix Dynamic Server, you would have a MONEY type which is a minor variant on the DECIMAL or NUMERIC type. It is always a fixed-point type (whereas DECIMAL can be a floating point type). You can specify a scale from 1 to 32, and a precision from 0 to 32 (defaulting to a scale of 16 and a precision of 2). So, depending on what you need to store, you might use DECIMAL(16,2) - still big enough to hold the US Federal Deficit, to the nearest cent - or you might use a smaller range, or more decimal places.

Mongoose: findOneAndUpdate doesn't return updated document

For whoever stumbled across this using ES6 / ES7 style with native promises, here is a pattern you can adopt...

const user = { id: 1, name: "Fart Face 3rd"};
const userUpdate = { name: "Pizza Face" };

try {
    user = await new Promise( ( resolve, reject ) => {
        User.update( { _id: user.id }, userUpdate, { upsert: true, new: true }, ( error, obj ) => {
            if( error ) {
                console.error( JSON.stringify( error ) );
                return reject( error );
            }

            resolve( obj );
        });
    })
} catch( error ) { /* set the world on fire */ }

How do I create dynamic variable names inside a loop?

I agree it is generally preferable to use an Array for this.

However, this can also be accomplished in JavaScript by simply adding properties to the current scope (the global scope, if top-level code; the function scope, if within a function) by simply using this – which always refers to the current scope.

for (var i = 0; i < coords.length; ++i) {
    this["marker"+i] = "some stuff";
}

You can later retrieve the stored values (if you are within the same scope as when they were set):

var foo = this.marker0;
console.log(foo); // "some stuff"

This slightly odd feature of JavaScript is rarely used (with good reason), but in certain situations it can be useful.

Hibernate Error: a different object with the same identifier value was already associated with the session

Try to place the code of your query before. That fix my problem. e.g. change this:

query1 
query2 - get the error 
update

to this:

query2
query1
update

Dark color scheme for Eclipse

Easiest way: change the Windows Display Properties main window background color. I went to Appearance tab, changed to Silver scheme, clicked Advanced, clicked on "Active Window" and changed Color 1 to a light gray. All Eclipse views softened.

Since Luna (4.4) there seems to be a full Dark them in

Window -> Preferences -> General -> Appearance -> Theme -> Dark

enter image description here

What's onCreate(Bundle savedInstanceState)

onCreate(Bundle savedInstanceState) Function in Android:

  1. When an Activity first call or launched then onCreate(Bundle savedInstanceState) method is responsible to create the activity.

  2. When ever orientation(i.e. from horizontal to vertical or vertical to horizontal) of activity gets changed or when an Activity gets forcefully terminated by any Operating System then savedInstanceState i.e. object of Bundle Class will save the state of an Activity.

  3. After Orientation changed then onCreate(Bundle savedInstanceState) will call and recreate the activity and load all data from savedInstanceState.

  4. Basically Bundle class is used to stored the data of activity whenever above condition occur in app.

  5. onCreate() is not required for apps. But the reason it is used in app is because that method is the best place to put initialization code.

  6. You could also put your initialization code in onStart() or onResume() and when you app will load first, it will work same as in onCreate().

Find TODO tags in Eclipse

Is there an easy way to view all methods which contain this comment? Some sort of menu option?

Yes, choose one of the following:

  1. Go to Window ? Show View ? Tasks (Not TaskList). The new view will show up where the "Console" and "Problems" tabs are by default.

  2. As mentioned elsewhere, you can see them next to the scroll bar as little blue rectangles if you have the source file in question open.

  3. If you just want the // TODO Auto-generated method stub messages (rather than all // TODO messages) you should use the search function (Ctrl-F for ones in this file Search ? Java Search ? Search string for the ability to specify this workspace, that file, this project, etc.)

What does it mean to write to stdout in C?

That means that you are printing output on the main output device for the session... whatever that may be. The user's console, a tty session, a file or who knows what. What that device may be varies depending on how the program is being run and from where.

The following command will write to the standard output device (stdout)...

printf( "hello world\n" );

Which is just another way, in essence, of doing this...

fprintf( stdout, "hello world\n" );

In which case stdout is a pointer to a FILE stream that represents the default output device for the application. You could also use

fprintf( stderr, "that didn't go well\n" );

in which case you would be sending the output to the standard error output device for the application which may, or may not, be the same as stdout -- as with stdout, stderr is a pointer to a FILE stream representing the default output device for error messages.

How to use jQuery to get the current value of a file input field

I think it should be

 $('#fileinput').val();

PHP Call to undefined function

This was a developer mistake - a misplaced ending brace, which made the above function a nested function.

I see a lot of questions related to the undefined function error in SO. Let me note down this as an answer, in case someone else have the same issue with function scope.

Things I tried to troubleshoot first:

  1. Searched for the php file with the function definition in it. Verified that the file exists.
  2. Verified that the require (or include) statement for the above file exists in the page. Also, verified the absolute path in the require/include is correct.
  3. Verified that the filename is spelled correctly in the require statement.
  4. Echoed a word in the included file, to see if it has been properly included.
  5. Defined a separate function at the end of file, and called it. It worked too.

It was difficult to trace the braces, since the functions were very long - problem with legacy systems. Further steps to troubleshoot were this:

  1. I already defined a simple print function at the end of included file. I moved it to just above the "undefined function". That made it undefined too.
  2. Identified this as some scope issue.

  3. Used the Netbeans collapse (code fold) feature to check the function just above this one. So, the 1000 lines function above just collapsed along with this one, making this a nested function.

  4. Once the problem identified, cut-pasted the function to the end of file, which solved the issue.

Is it possible to make input fields read-only through CSS?

The read-only attribute in HTML is used to create a text input non-editable. But in case of CSS, the pointer-events property is used to stop the pointer events.

Syntax:

pointer-events: none;

Example: This example shows two input text, in which one is non-editable.

<!DOCTYPE html> 
<html> 
    <head> 
        <title> 
            Disable Text Input field 
        </title> 

        <style> 
        .inputClass { 
            pointer-events: none; 
        } 
        </style> 
    </head> 

    <body style = "text-align:center;">
        Non-editable:<input class="inputClass" name="input" value="NonEditable"> 

        <br><br> 

        Editable:<input name="input" value="Editable"> 
    </body> 
</html>                  

Edit static

Error - Unable to access the IIS metabase

Run command:

c:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -ga %username%
c:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -i

How to Select Columns in Editors (Atom,Notepad++, Kate, VIM, Sublime, Textpad,etc) and IDEs (NetBeans, IntelliJ IDEA, Eclipse, Visual Studio, etc)

in Notepad++ , you can select a particular column holding ctrl + alt + shift and then left click mouse button and drag to select.

Adding files to java classpath at runtime

You can only add folders or jar files to a class loader. So if you have a single class file, you need to put it into the appropriate folder structure first.

Here is a rather ugly hack that adds to the SystemClassLoader at runtime:

import java.io.IOException;
import java.io.File;
import java.net.URLClassLoader;
import java.net.URL;
import java.lang.reflect.Method;

public class ClassPathHacker {

  private static final Class[] parameters = new Class[]{URL.class};

  public static void addFile(String s) throws IOException {
    File f = new File(s);
    addFile(f);
  }//end method

  public static void addFile(File f) throws IOException {
    addURL(f.toURL());
  }//end method


  public static void addURL(URL u) throws IOException {

    URLClassLoader sysloader = (URLClassLoader) ClassLoader.getSystemClassLoader();
    Class sysclass = URLClassLoader.class;

    try {
      Method method = sysclass.getDeclaredMethod("addURL", parameters);
      method.setAccessible(true);
      method.invoke(sysloader, new Object[]{u});
    } catch (Throwable t) {
      t.printStackTrace();
      throw new IOException("Error, could not add URL to system classloader");
    }//end try catch

   }//end method

}//end class

The reflection is necessary to access the protected method addURL. This could fail if there is a SecurityManager.

jquery disable form submit on enter

$('form').keyup(function(e) {
  return e.which !== 13  
});

The event.which property normalizes event.keyCode and event.charCode. It is recommended to watch event.which for keyboard key input.

which docs.

Why doesn't Git ignore my specified file?

What I did it to ignore the settings.php file successfully:

  1. git rm --cached sites/default/settings.php
  2. commit (up to here didn't work)
  3. manually deleted sites/default/settings.php (this did the trick)
  4. git add .
  5. commit (ignored successfully)

I think if there's the committed file on Git then ignore doesn't work as expected. Just delete the file and commit. Afterwards it'll ignore.

Skip to next iteration in loop vba

I use Goto

  For x= 1 to 20

       If something then goto continue

       skip this code

  Continue:

  Next x

Get top n records for each group of grouped results

SELECT
p1.Person,
p1.`GROUP`,
p1.Age  
   FROM
person AS p1 
 WHERE
(
SELECT
    COUNT( DISTINCT ( p2.age ) ) 
FROM
    person AS p2 
WHERE
    p2.`GROUP` = p1.`GROUP` 
    AND p2.Age >= p1.Age 
) < 2 
ORDER BY
p1.`GROUP` ASC,
p1.age DESC

reference leetcode

<button> background image

Replace button #rock With #rock

No need for additional selector scope. You're using an id which is as specific as you can be.

JsBin example: http://jsbin.com/idobar/1/edit

Rails: Using greater than/less than with a where statement

I've only tested this in Rails 4 but there's an interesting way to use a range with a where hash to get this behavior.

User.where(id: 201..Float::INFINITY)

will generate the SQL

SELECT `users`.* FROM `users`  WHERE (`users`.`id` >= 201)

The same can be done for less than with -Float::INFINITY.

I just posted a similar question asking about doing this with dates here on SO.

>= vs >

To avoid people having to dig through and follow the comments conversation here are the highlights.

The method above only generates a >= query and not a >. There are many ways to handle this alternative.

For discrete numbers

You can use a number_you_want + 1 strategy like above where I'm interested in Users with id > 200 but actually look for id >= 201. This is fine for integers and numbers where you can increment by a single unit of interest.

If you have the number extracted into a well named constant this may be the easiest to read and understand at a glance.

Inverted logic

We can use the fact that x > y == !(x <= y) and use the where not chain.

User.where.not(id: -Float::INFINITY..200)

which generates the SQL

SELECT `users`.* FROM `users` WHERE (NOT (`users`.`id` <= 200))

This takes an extra second to read and reason about but will work for non discrete values or columns where you can't use the + 1 strategy.

Arel table

If you want to get fancy you can make use of the Arel::Table.

User.where(User.arel_table[:id].gt(200))

will generate the SQL

"SELECT `users`.* FROM `users` WHERE (`users`.`id` > 200)"

The specifics are as follows:

User.arel_table              #=> an Arel::Table instance for the User model / users table
User.arel_table[:id]         #=> an Arel::Attributes::Attribute for the id column
User.arel_table[:id].gt(200) #=> an Arel::Nodes::GreaterThan which can be passed to `where`

This approach will get you the exact SQL you're interested in however not many people use the Arel table directly and can find it messy and/or confusing. You and your team will know what's best for you.

Bonus

Starting in Rails 5 you can also do this with dates!

User.where(created_at: 3.days.ago..DateTime::Infinity.new)

will generate the SQL

SELECT `users`.* FROM `users` WHERE (`users`.`created_at` >= '2018-07-07 17:00:51')

Double Bonus

Once Ruby 2.6 is released (December 25, 2018) you'll be able to use the new infinite range syntax! Instead of 201..Float::INFINITY you'll be able to just write 201... More info in this blog post.

What is the copy-and-swap idiom?

Overview

Why do we need the copy-and-swap idiom?

Any class that manages a resource (a wrapper, like a smart pointer) needs to implement The Big Three. While the goals and implementation of the copy-constructor and destructor are straightforward, the copy-assignment operator is arguably the most nuanced and difficult. How should it be done? What pitfalls need to be avoided?

The copy-and-swap idiom is the solution, and elegantly assists the assignment operator in achieving two things: avoiding code duplication, and providing a strong exception guarantee.

How does it work?

Conceptually, it works by using the copy-constructor's functionality to create a local copy of the data, then takes the copied data with a swap function, swapping the old data with the new data. The temporary copy then destructs, taking the old data with it. We are left with a copy of the new data.

In order to use the copy-and-swap idiom, we need three things: a working copy-constructor, a working destructor (both are the basis of any wrapper, so should be complete anyway), and a swap function.

A swap function is a non-throwing function that swaps two objects of a class, member for member. We might be tempted to use std::swap instead of providing our own, but this would be impossible; std::swap uses the copy-constructor and copy-assignment operator within its implementation, and we'd ultimately be trying to define the assignment operator in terms of itself!

(Not only that, but unqualified calls to swap will use our custom swap operator, skipping over the unnecessary construction and destruction of our class that std::swap would entail.)


An in-depth explanation

The goal

Let's consider a concrete case. We want to manage, in an otherwise useless class, a dynamic array. We start with a working constructor, copy-constructor, and destructor:

#include <algorithm> // std::copy
#include <cstddef> // std::size_t

class dumb_array
{
public:
    // (default) constructor
    dumb_array(std::size_t size = 0)
        : mSize(size),
          mArray(mSize ? new int[mSize]() : nullptr)
    {
    }

    // copy-constructor
    dumb_array(const dumb_array& other)
        : mSize(other.mSize),
          mArray(mSize ? new int[mSize] : nullptr),
    {
        // note that this is non-throwing, because of the data
        // types being used; more attention to detail with regards
        // to exceptions must be given in a more general case, however
        std::copy(other.mArray, other.mArray + mSize, mArray);
    }

    // destructor
    ~dumb_array()
    {
        delete [] mArray;
    }

private:
    std::size_t mSize;
    int* mArray;
};

This class almost manages the array successfully, but it needs operator= to work correctly.

A failed solution

Here's how a naive implementation might look:

// the hard part
dumb_array& operator=(const dumb_array& other)
{
    if (this != &other) // (1)
    {
        // get rid of the old data...
        delete [] mArray; // (2)
        mArray = nullptr; // (2) *(see footnote for rationale)

        // ...and put in the new
        mSize = other.mSize; // (3)
        mArray = mSize ? new int[mSize] : nullptr; // (3)
        std::copy(other.mArray, other.mArray + mSize, mArray); // (3)
    }

    return *this;
}

And we say we're finished; this now manages an array, without leaks. However, it suffers from three problems, marked sequentially in the code as (n).

  1. The first is the self-assignment test. This check serves two purposes: it's an easy way to prevent us from running needless code on self-assignment, and it protects us from subtle bugs (such as deleting the array only to try and copy it). But in all other cases it merely serves to slow the program down, and act as noise in the code; self-assignment rarely occurs, so most of the time this check is a waste. It would be better if the operator could work properly without it.

  2. The second is that it only provides a basic exception guarantee. If new int[mSize] fails, *this will have been modified. (Namely, the size is wrong and the data is gone!) For a strong exception guarantee, it would need to be something akin to:

    dumb_array& operator=(const dumb_array& other)
    {
        if (this != &other) // (1)
        {
            // get the new data ready before we replace the old
            std::size_t newSize = other.mSize;
            int* newArray = newSize ? new int[newSize]() : nullptr; // (3)
            std::copy(other.mArray, other.mArray + newSize, newArray); // (3)
    
            // replace the old data (all are non-throwing)
            delete [] mArray;
            mSize = newSize;
            mArray = newArray;
        }
    
        return *this;
    }
    
  3. The code has expanded! Which leads us to the third problem: code duplication. Our assignment operator effectively duplicates all the code we've already written elsewhere, and that's a terrible thing.

In our case, the core of it is only two lines (the allocation and the copy), but with more complex resources this code bloat can be quite a hassle. We should strive to never repeat ourselves.

(One might wonder: if this much code is needed to manage one resource correctly, what if my class manages more than one? While this may seem to be a valid concern, and indeed it requires non-trivial try/catch clauses, this is a non-issue. That's because a class should manage one resource only!)

A successful solution

As mentioned, the copy-and-swap idiom will fix all these issues. But right now, we have all the requirements except one: a swap function. While The Rule of Three successfully entails the existence of our copy-constructor, assignment operator, and destructor, it should really be called "The Big Three and A Half": any time your class manages a resource it also makes sense to provide a swap function.

We need to add swap functionality to our class, and we do that as follows†:

class dumb_array
{
public:
    // ...

    friend void swap(dumb_array& first, dumb_array& second) // nothrow
    {
        // enable ADL (not necessary in our case, but good practice)
        using std::swap;

        // by swapping the members of two objects,
        // the two objects are effectively swapped
        swap(first.mSize, second.mSize);
        swap(first.mArray, second.mArray);
    }

    // ...
};

(Here is the explanation why public friend swap.) Now not only can we swap our dumb_array's, but swaps in general can be more efficient; it merely swaps pointers and sizes, rather than allocating and copying entire arrays. Aside from this bonus in functionality and efficiency, we are now ready to implement the copy-and-swap idiom.

Without further ado, our assignment operator is:

dumb_array& operator=(dumb_array other) // (1)
{
    swap(*this, other); // (2)

    return *this;
}

And that's it! With one fell swoop, all three problems are elegantly tackled at once.

Why does it work?

We first notice an important choice: the parameter argument is taken by-value. While one could just as easily do the following (and indeed, many naive implementations of the idiom do):

dumb_array& operator=(const dumb_array& other)
{
    dumb_array temp(other);
    swap(*this, temp);

    return *this;
}

We lose an important optimization opportunity. Not only that, but this choice is critical in C++11, which is discussed later. (On a general note, a remarkably useful guideline is as follows: if you're going to make a copy of something in a function, let the compiler do it in the parameter list.‡)

Either way, this method of obtaining our resource is the key to eliminating code duplication: we get to use the code from the copy-constructor to make the copy, and never need to repeat any bit of it. Now that the copy is made, we are ready to swap.

Observe that upon entering the function that all the new data is already allocated, copied, and ready to be used. This is what gives us a strong exception guarantee for free: we won't even enter the function if construction of the copy fails, and it's therefore not possible to alter the state of *this. (What we did manually before for a strong exception guarantee, the compiler is doing for us now; how kind.)

At this point we are home-free, because swap is non-throwing. We swap our current data with the copied data, safely altering our state, and the old data gets put into the temporary. The old data is then released when the function returns. (Where upon the parameter's scope ends and its destructor is called.)

Because the idiom repeats no code, we cannot introduce bugs within the operator. Note that this means we are rid of the need for a self-assignment check, allowing a single uniform implementation of operator=. (Additionally, we no longer have a performance penalty on non-self-assignments.)

And that is the copy-and-swap idiom.

What about C++11?

The next version of C++, C++11, makes one very important change to how we manage resources: the Rule of Three is now The Rule of Four (and a half). Why? Because not only do we need to be able to copy-construct our resource, we need to move-construct it as well.

Luckily for us, this is easy:

class dumb_array
{
public:
    // ...

    // move constructor
    dumb_array(dumb_array&& other) noexcept ††
        : dumb_array() // initialize via default constructor, C++11 only
    {
        swap(*this, other);
    }

    // ...
};

What's going on here? Recall the goal of move-construction: to take the resources from another instance of the class, leaving it in a state guaranteed to be assignable and destructible.

So what we've done is simple: initialize via the default constructor (a C++11 feature), then swap with other; we know a default constructed instance of our class can safely be assigned and destructed, so we know other will be able to do the same, after swapping.

(Note that some compilers do not support constructor delegation; in this case, we have to manually default construct the class. This is an unfortunate but luckily trivial task.)

Why does that work?

That is the only change we need to make to our class, so why does it work? Remember the ever-important decision we made to make the parameter a value and not a reference:

dumb_array& operator=(dumb_array other); // (1)

Now, if other is being initialized with an rvalue, it will be move-constructed. Perfect. In the same way C++03 let us re-use our copy-constructor functionality by taking the argument by-value, C++11 will automatically pick the move-constructor when appropriate as well. (And, of course, as mentioned in previously linked article, the copying/moving of the value may simply be elided altogether.)

And so concludes the copy-and-swap idiom.


Footnotes

*Why do we set mArray to null? Because if any further code in the operator throws, the destructor of dumb_array might be called; and if that happens without setting it to null, we attempt to delete memory that's already been deleted! We avoid this by setting it to null, as deleting null is a no-operation.

†There are other claims that we should specialize std::swap for our type, provide an in-class swap along-side a free-function swap, etc. But this is all unnecessary: any proper use of swap will be through an unqualified call, and our function will be found through ADL. One function will do.

‡The reason is simple: once you have the resource to yourself, you may swap and/or move it (C++11) anywhere it needs to be. And by making the copy in the parameter list, you maximize optimization.

††The move constructor should generally be noexcept, otherwise some code (e.g. std::vector resizing logic) will use the copy constructor even when a move would make sense. Of course, only mark it noexcept if the code inside doesn't throw exceptions.

Default keystore file does not exist?

You must be providing the wrong path to the debug.keystore file.

Follow these steps to get the correct path and complete your command:

  1. In eclipse, click the Window menu -> Preferences -> Expand Android -> Build
  2. In the right panel, look for: Default debug keystore:
  3. Select the entire box next to the label specified in Step 2

And finally, use the path you just copied from Step 3 to construct your command:

For example, in my case, it would be:

C:\Program Files\Java\jre7\bin>keytool -list -v -keystore "C:\Users\Siddharth Lele.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

UPDATED:

If you had already followed the steps mentioned above, the only other solution is to delete the debug.keystore and let Eclipse recreate it for you.

Step 1: Go to the path where your keystore is stored. In your case, C:\Users\Suresh\.android\debug.keystore

Step 2: Close and restart Eclipse.

Step 3 (Optional): You may need to clean your project before the debug.keystore is created again.

Source: http://www.coderanch.com/t/440920/Security/KeyTool-genkeypair-exception-Keystore-file

You can refer to this for the part about deleting your debug.keystore file: "Debug certificate expired" error in Eclipse Android plugins

How to print multiple lines of text with Python

The triple quotes answer is great for ASCII art, but for those wondering - what if my multiple lines are a tuple, list, or other iterable that returns strings (perhaps a list comprehension?), then how about:

print("\n".join(<*iterable*>))

For example:

print("\n".join(["{}={}".format(k, v) for k, v in os.environ.items() if 'PATH' in k]))

How do I create HTML table using jQuery dynamically?

You may use two options:

  1. createElement
  2. InnerHTML

Create Element is the fastest way (check here.):

$(document.createElement('table'));

InnerHTML is another popular approach:

$("#foo").append("<div>hello world</div>"); // Check similar for table too.

Check a real example on How to create a new table with rows using jQuery and wrap it inside div.

There may be other approaches as well. Please use this as a starting point and not as a copy-paste solution.

Edit:

Check Dynamic creation of table with DOM

Edit 2:

IMHO, you are mixing object and inner HTML. Let's try with a pure inner html approach:

function createProviderFormFields(id, labelText, tooltip, regex) {
    var tr = '<tr>' ;
         // create a new textInputBox  
           var textInputBox = '<input type="text" id="' + id + '" name="' + id + '" title="' + tooltip + '" />';  
        // create a new Label Text
            tr += '<td>' + labelText  + '</td>';
            tr += '<td>' + textInputBox + '</td>';  
    tr +='</tr>';
    return tr;
}

Show percent % instead of counts in charts of categorical variables

Since version 3.3 of ggplot2, we have access to the convenient after_stat() function.

We can do something similar to @Andrew's answer, but without using the .. syntax:

# original example data
mydata <- c("aa", "bb", NULL, "bb", "cc", "aa", "aa", "aa", "ee", NULL, "cc")

# display percentages
library(ggplot2)
ggplot(mapping = aes(x = mydata,
                     y = after_stat(count/sum(count)))) +
  geom_bar() +
  scale_y_continuous(labels = scales::percent)

You can find all the "computed variables" available to use in the documentation of the geom_ and stat_ functions. For example, for geom_bar(), you can access the count and prop variables. (See the documentation for computed variables.)

One comment about your NULL values: they are ignored when you create the vector (i.e. you end up with a vector of length 9, not 11). If you really want to keep track of missing data, you will have to use NA instead (ggplot2 will put NAs at the right end of the plot):

# use NA instead of NULL
mydata <- c("aa", "bb", NA, "bb", "cc", "aa", "aa", "aa", "ee", NA, "cc")
length(mydata)
#> [1] 11

# display percentages
library(ggplot2)
ggplot(mapping = aes(x = mydata,
                     y = after_stat(count/sum(count)))) +
  geom_bar() +
  scale_y_continuous(labels = scales::percent)

Created on 2021-02-09 by the reprex package (v1.0.0)

(Note that using chr or fct data will not make a difference for your example.)

How do I find the MySQL my.cnf location

This might work:

strace mysql ";" 2>&1  | grep cnf

on my machine this outputs:

stat64("/etc/my.cnf", 0xbf9faafc)       = -1 ENOENT (No such file or directory)
stat64("/etc/mysql/my.cnf", {st_mode=S_IFREG|0644, st_size=4271, ...}) = 0
open("/etc/mysql/my.cnf", O_RDONLY|O_LARGEFILE) = 3
read(3, "# /etc/mysql/my.cnf: The global "..., 4096) = 4096
stat64("/home/xxxxx/.my.cnf", 0xbf9faafc) = -1 ENOENT (No such file or directory)

So it looks like /etc/mysql/my.cnf is the one since it stat64() and read() were successful.

If "0" then leave the cell blank

Use =IF(H15+G16-F16=0,"",H15+G16-F16)

Correct set of dependencies for using Jackson mapper

Apart from fixing the imports, do a fresh maven clean compile -U. Note the -U option, that brings in new dependencies which sometimes the editor has hard time with. Let the compilation fail due to un-imported classes, but at least you have an option to import them after the maven command.

Just doing Maven->Reimport from Intellij did not work for me.

$(document).ready(function(){ Uncaught ReferenceError: $ is not defined

Put this code in the <head></head> tags:

<script type="text/javascript" src="http://code.jquery.com/jquery-1.10.0.min.js"></script>

Check if object is a jQuery object

You may also use the .jquery property as described here: http://api.jquery.com/jquery-2/

var a = { what: "A regular JS object" },
b = $('body');

if ( a.jquery ) { // falsy, since it's undefined
    alert(' a is a jQuery object! ');    
}

if ( b.jquery ) { // truthy, since it's a string
    alert(' b is a jQuery object! ');
}

How to test if JSON object is empty in Java

Use the following code:

if(json.isNull()!= null){  //returns true only if json is not null

}

Finding length of char array

By convention C strings are 'null-terminated'. That means that there's an extra byte at the end with the value of zero (0x00). Any function that does something with a string (like printf) will consider a string to end when it finds null. This also means that if your string is not null terminated, it will keep going until it finds a null character, which can produce some interesting results!

As the first item in your array is 0x00, it will be considered to be length zero (no characters).

If you defined your string to be:

char a[7]={0xdc,0x01,0x04,0x00};

e.g. null-terminated

then you can use strlen to measure the length of the string stored in the array.

sizeof measures the size of a type. It is not what you want. Also remember that the string in an array may be shorter than the size of the array.

How to create and handle composite primary key in JPA

You can make an Embedded class, which contains your two keys, and then have a reference to that class as EmbeddedId in your Entity.

You would need the @EmbeddedId and @Embeddable annotations.

@Entity
public class YourEntity {
    @EmbeddedId
    private MyKey myKey;

    @Column(name = "ColumnA")
    private String columnA;

    /** Your getters and setters **/
}
@Embeddable
public class MyKey implements Serializable {

    @Column(name = "Id", nullable = false)
    private int id;

    @Column(name = "Version", nullable = false)
    private int version;

    /** getters and setters **/
}

Another way to achieve this task is to use @IdClass annotation, and place both your id in that IdClass. Now you can use normal @Id annotation on both the attributes

@Entity
@IdClass(MyKey.class)
public class YourEntity {
   @Id
   private int id;
   @Id
   private int version;

}

public class MyKey implements Serializable {
   private int id;
   private int version;
}

How does += (plus equal) work?

NO 1+=2!=2 it means you are going to add 1+2. But this will give you a syntax error. Assume if a variable is int type int a=1; then a+=2; means a=1+2; and increase the value of a from 1 to 3.

How do I get the value of a registry key and ONLY the value using powershell

Not sure at what version this capability arrived, but you can use something like this to return all the properties of multiple child registry entries in an array:

$InstalledSoftware = Get-ChildItem "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall" | ForEach-Object {Get-ItemProperty "Registry::$_"}

Only adding this as Google brought me here for a relevant reason and I eventually came up with the above one-liner for dredging the registry.

Five equal columns in twitter bootstrap

I've created SASS mixin definitions based on bootstrap definitions for any number of columns (personally beside 12 I use 8, 10 and 24):

// Extended bootstrap grid system
//
// Framework grid generation
//
// Based on Bootstrap 'bootstrap/_grid-framework.scss'. Generates classes in form of `.col-(size)-x-num` of width x/num.

@mixin make-extended-grid-columns($num-columns, $i: 1, $list: ".col-xs-#{$i}-#{$num-columns}, .col-sm-#{$i}-#{$num-columns}, .col-md-#{$i}-#{$num-columns}, .col-lg-#{$i}-#{$num-columns}") {
    @for $i from (1 + 1) through $num-columns {
        $list: "#{$list}, .col-xs-#{$i}-#{$num-columns}, .col-sm-#{$i}-#{$num-columns}, .col-md-#{$i}-#{$num-columns}, .col-lg-#{$i}-#{$num-columns}";
    }
    #{$list} {
        position: relative;
        min-height: 1px;
        padding-left:  ($grid-gutter-width / 2);
        padding-right: ($grid-gutter-width / 2);
    }
}


@mixin float-extended-grid-columns($class, $num-columns, $i: 1, $list: ".col-#{$class}-#{$i}-#{$num-columns}") {
    @for $i from (1 + 1) through $num-columns {
        $list: "#{$list}, .col-#{$class}-#{$i}-#{$num-columns}";
    }
    #{$list} {
        float: left;
    }
}


@mixin calc-extended-grid-column($index, $num-columns, $class, $type) {
    @if ($type == width) and ($index > 0) {
        .col-#{$class}-#{$index}-#{$num-columns} {
            width: percentage(($index / $num-columns));
        }
    }
    @if ($type == push) and ($index > 0) {
        .col-#{$class}-push-#{$index}-#{$num-columns} {
            left: percentage(($index / $num-columns));
        }
    }
    @if ($type == pull) and ($index > 0) {
        .col-#{$class}-pull-#{$index}-#{$num-columns} {
            right: percentage(($index / $num-columns));
        }
    }
    @if ($type == offset) and ($index > 0) {
        .col-#{$class}-offset-#{$index}-#{$num-columns} {
            margin-left: percentage(($index / $num-columns));
        }
    }
}

@mixin loop-extended-grid-columns($num-columns, $class, $type) {
    @for $i from 1 through $num-columns - 1 {
        @include calc-extended-grid-column($i, $num-columns, $class, $type);
    }
}

@mixin make-extended-grid($class, $num-columns) {
    @include float-extended-grid-columns($class, $num-columns);
    @include loop-extended-grid-columns($num-columns, $class, width);
    @include loop-extended-grid-columns($num-columns, $class, pull);
    @include loop-extended-grid-columns($num-columns, $class, push);
    @include loop-extended-grid-columns($num-columns, $class, offset);
}

And you can simply create classes by:

$possible-number-extended-grid-columns: 8, 10, 24;

@each $num-columns in $possible-number-extended-grid-columns {

  // Columns

  @include make-extended-grid-columns($num-columns);

  // Extra small grid

  @include make-extended-grid(xs, $num-columns);

  // Small grid

  @media (min-width: $screen-sm-min) {
    @include make-extended-grid(sm, $num-columns);
  }

  // Medium grid

  @media (min-width: $screen-md-min) {
    @include make-extended-grid(md, $num-columns);
  }

  // Large grid

  @media (min-width: $screen-lg-min) {
    @include make-extended-grid(lg, $num-columns);
  }

}

I hope someone will find it useful

IsNumeric function in c#

You could make a helper method. Something like:

public bool IsNumeric(string input) {
    int test;
    return int.TryParse(input, out test);
}

Populate one dropdown based on selection in another

Setup mine within a closure and with straight JavaScript, explanation provided in comments

_x000D_
_x000D_
(function() {_x000D_
_x000D_
  //setup an object fully of arrays_x000D_
  //alternativly it could be something like_x000D_
  //{"yes":[{value:sweet, text:Sweet}.....]}_x000D_
  //so you could set the label of the option tag something different than the name_x000D_
  var bOptions = {_x000D_
    "yes": ["sweet", "wohoo", "yay"],_x000D_
    "no": ["you suck!", "common son"]_x000D_
  };_x000D_
_x000D_
  var A = document.getElementById('A');_x000D_
  var B = document.getElementById('B');_x000D_
_x000D_
  //on change is a good event for this because you are guarenteed the value is different_x000D_
  A.onchange = function() {_x000D_
    //clear out B_x000D_
    B.length = 0;_x000D_
    //get the selected value from A_x000D_
    var _val = this.options[this.selectedIndex].value;_x000D_
    //loop through bOption at the selected value_x000D_
    for (var i in bOptions[_val]) {_x000D_
      //create option tag_x000D_
      var op = document.createElement('option');_x000D_
      //set its value_x000D_
      op.value = bOptions[_val][i];_x000D_
      //set the display label_x000D_
      op.text = bOptions[_val][i];_x000D_
      //append it to B_x000D_
      B.appendChild(op);_x000D_
    }_x000D_
  };_x000D_
  //fire this to update B on load_x000D_
  A.onchange();_x000D_
_x000D_
})();
_x000D_
<select id='A' name='A'>_x000D_
  <option value='yes' selected='selected'>yes_x000D_
  <option value='no'> no_x000D_
</select>_x000D_
<select id='B' name='B'>_x000D_
</select>
_x000D_
_x000D_
_x000D_

How to determine if binary tree is balanced?

If this is for your job, I suggest:

  1. do not reinvent the wheel and
  2. use/buy COTS instead of fiddling with bits.
  3. Save your time/energy for solving business problems.

Label on the left side instead above an input field

You must float left all elements like so:

.form-group,
.form-group label,
.form-group input { float:left; display:inline;   }

give some margin to the desired elements :

 .form-group { margin-right:5px }

and set the label the same line height as the height of the fields:

.form-group label { line-height:--px; }

How to resolve 'npm should be run outside of the node repl, in your normal shell'

If you're like me running in a restricted environment without administrative privileges, that means your only way to get node up and running is to grab the executable (node.exe) without using the installer. You also cannot change the path variable which makes it that much more challenging.

Here's what I did (for Windows)

  1. Throw node.exe into its own folder (Downloaded the node.exe stand-alone )
  2. Grab an NPM release zip off of github: https://github.com/npm/npm/releases
  3. Create a folder named: node_modules in the node.exe folder
  4. Extract the NPM zip into the node_modules folder
  5. Make sure the top most folder is named npm (remove any of the versioning on the npm folder name ie: npm-2.12.1 --> npm)
  6. Copy npm.cmd out of the npm/bin folder into the top most folder with node.exe
  7. Open a command prompt to the node.exe directory (shift right-click "Open command window here")
  8. Now you will be able to run your npm installers via: npm install -g express

Running the installers through npm will now auto install packages where they need to be located (node_modules and the root)

Don't forget you will not be able to set the path variable if you do not have proper permissions. So your best route is to open a command prompt in the node.exe directory (shift right-click "Open command window here")

How to do a non-greedy match in grep?

You're looking for a non-greedy (or lazy) match. To get a non-greedy match in regular expressions you need to use the modifier ? after the quantifier. For example you can change .* to .*?.

By default grep doesn't support non-greedy modifiers, but you can use grep -P to use the Perl syntax.

Angular window resize event

Here is a better way to do it. Based on Birowsky's answer.

Step 1: Create an angular service with RxJS Observables.

import { Injectable } from '@angular/core';
import { Observable, BehaviorSubject } from 'rxjs';

@Injectable()
export class WindowService {
    height$: Observable<number>;
    //create more Observables as and when needed for various properties
    hello: string = "Hello";
    constructor() {
        let windowSize$ = new BehaviorSubject(getWindowSize());

        this.height$ = (windowSize$.pluck('height') as Observable<number>).distinctUntilChanged();

        Observable.fromEvent(window, 'resize')
            .map(getWindowSize)
            .subscribe(windowSize$);
    }

}

function getWindowSize() {
    return {
        height: window.innerHeight
        //you can sense other parameters here
    };
};

Step 2: Inject the above service and subscribe to any of the Observables created within the service wherever you would like to receive the window resize event.

import { Component } from '@angular/core';
//import service
import { WindowService } from '../Services/window.service';

@Component({
    selector: 'pm-app',
    templateUrl: './componentTemplates/app.component.html',
    providers: [WindowService]
})
export class AppComponent { 

    constructor(private windowService: WindowService) {

        //subscribe to the window resize event
        windowService.height$.subscribe((value:any) => {
            //Do whatever you want with the value.
            //You can also subscribe to other observables of the service
        });
    }

}

A sound understanding of Reactive Programming will always help in overcoming difficult problems. Hope this helps someone.

How to generate the "create table" sql statement for an existing table in postgreSQL

Here is a bit improved version of shekwi's query.
It generates the primary key constraint and is able to handle temporary tables:

with pkey as
(
    select cc.conrelid, format(E',
    constraint %I primary key(%s)', cc.conname,
        string_agg(a.attname, ', ' 
            order by array_position(cc.conkey, a.attnum))) pkey
    from pg_catalog.pg_constraint cc
        join pg_catalog.pg_class c on c.oid = cc.conrelid
        join pg_catalog.pg_attribute a on a.attrelid = cc.conrelid 
            and a.attnum = any(cc.conkey)
    where cc.contype = 'p'
    group by cc.conrelid, cc.conname
)
select format(E'create %stable %s%I\n(\n%s%s\n);\n',
    case c.relpersistence when 't' then 'temporary ' else '' end,
    case c.relpersistence when 't' then '' else n.nspname || '.' end,
    c.relname,
    string_agg(
        format(E'\t%I %s%s',
            a.attname,
            pg_catalog.format_type(a.atttypid, a.atttypmod),
            case when a.attnotnull then ' not null' else '' end
        ), E',\n'
        order by a.attnum
    ),
    (select pkey from pkey where pkey.conrelid = c.oid)) as sql
from pg_catalog.pg_class c
    join pg_catalog.pg_namespace n on n.oid = c.relnamespace
    join pg_catalog.pg_attribute a on a.attrelid = c.oid and a.attnum > 0
    join pg_catalog.pg_type t on a.atttypid = t.oid
where c.relname = :table_name
group by c.oid, c.relname, c.relpersistence, n.nspname;

Use table_name parameter to specify the name of the table.

List files ONLY in the current directory

Just use os.listdir and os.path.isfile instead of os.walk.

Example:

import os
files = [f for f in os.listdir('.') if os.path.isfile(f)]
for f in files:
    # do something

But be careful while applying this to other directory, like

files = [f for f in os.listdir(somedir) if os.path.isfile(f)].

which would not work because f is not a full path but relative to the current dir.

Therefore, for filtering on another directory, do os.path.isfile(os.path.join(somedir, f))

(Thanks Causality for the hint)

Android Studio Gradle project "Unable to start the daemon process /initialization of VM"

Try disabling firewall.

This might be a very weird solution but I had the same problem and I'm running Android 2.3 on windows 32 bit . I deleted the current app and disabled firewall. Upon creating a new project everything worked fine.

Replace all particular values in a data frame

Since PikkuKatja and glallen asked for a more general solution and I cannot comment yet, I'll write an answer. You can combine statements as in:

> df[df=="" | df==12] <- NA
> df
     A    B
1  <NA> <NA>
2  xyz  <NA>
3  jkl  100

For factors, zxzak's code already yields factors:

> df <- data.frame(list(A=c("","xyz","jkl"), B=c(12,"",100)))
> str(df)
'data.frame':   3 obs. of  2 variables:
 $ A: Factor w/ 3 levels "","jkl","xyz": 1 3 2
 $ B: Factor w/ 3 levels "","100","12": 3 1 2

If in trouble, I'd suggest to temporarily drop the factors.

df[] <- lapply(df, as.character)

HTML5 Dynamically create Canvas

 <html>
 <head></head>
 <body>
 <canvas id="canvas" width="300" height="300"></canvas>
 <script>
  var sun = new Image();
  var moon = new Image();
  var earth = new Image();
  function init() {
  sun.src = 'https://mdn.mozillademos.org/files/1456/Canvas_sun.png';
  moon.src = 'https://mdn.mozillademos.org/files/1443/Canvas_moon.png';
  earth.src = 'https://mdn.mozillademos.org/files/1429/Canvas_earth.png';
  window.requestAnimationFrame(draw);
  }

  function draw() {
  var ctx = document.getElementById('canvas').getContext('2d');

  ctx.globalCompositeOperation = 'destination-over';
  ctx.clearRect(0, 0, 300, 300);

  ctx.fillStyle = 'rgba(0, 0, 0, 0.4)';
  ctx.strokeStyle = 'rgba(0, 153, 255, 0.4)';
  ctx.save();
  ctx.translate(150, 150);

  // Earth
  var time = new Date();
  ctx.rotate(((2 * Math.PI) / 60) * time.getSeconds() + ((2 * Math.PI) / 60000) * 
  time.getMilliseconds());
  ctx.translate(105, 0);
  ctx.fillRect(10, -19, 55, 31); 
  ctx.drawImage(earth, -12, -12);

   // Moon
  ctx.save();
  ctx.rotate(((2 * Math.PI) / 6) * time.getSeconds() + ((2 * Math.PI) / 6000) * 
  time.getMilliseconds());
  ctx.translate(0, 28.5);
  ctx.drawImage(moon, -3.5, -3.5);
  ctx.restore();

  ctx.restore();

   ctx.beginPath();
   ctx.arc(150, 150, 105, 0, Math.PI * 2, false);
   ctx.stroke();

   ctx.drawImage(sun, 0, 0, 300, 300);

   window.requestAnimationFrame(draw);
    }

   init();
   </script>
   </body>
   </html>

exceeds the list view threshold 5000 items in Sharepoint 2010

The setting for the list throttle

  • Open the SharePoint Central Administration,
  • go to Application Management --> Manage Web Applications
  • Click to select the web application that hosts your list (eg. SharePoint - 80)
  • At the Ribbon, select the General Settings and select Resource Throttling
  • Then, you can see the 5000 List View Threshold limit and you can edit the value you want.
  • Click OK to save it.

For addtional reading: http://blogs.msdn.com/b/dinaayoub/archive/2010/04/22/sharepoint-2010-how-to-change-the-list-view-threshold.aspx

DISTINCT clause with WHERE

simple query this query select all record from table where email is unique:

select distinct email,* from table_name

How do I delete everything in Redis?

Answers so far are absolutely correct; they delete all keys.

However, if you also want to delete all Lua scripts from the Redis instance, you should follow it by:

SCRIPT FLUSH

The OP asks two questions; this completes the second question (everything wiped).

"SSL certificate verify failed" using pip to install packages

One note on the above answers: it is no longer sufficient to add just pypi.python.org to the trusted-hosts in the case where you are behind an HTTPS-intercepting proxy (we have zScaler).

I currently have the following in my pip.ini:

trusted-host = pypi.python.org pypi.org files.pythonhosted.org

Running pip -v install pkg will give you some hints as to which hosts might need to be added.

http://localhost:50070 does not work HADOOP

First, check that java processes that are running using "jps". If you are in a pseudo-distributed mode you must have the following proccesses:

  • Namenode
  • Jobtracker
  • Tasktracker
  • Datanode
  • SecondaryNamenode

If you are missing any, use the restart commands:

$HADOOP_INSTALL/bin/stop-all.sh
$HADOOP_INSTALL/bin/start-all.sh

It can also be because you haven't open that port on the machine:

iptables -A INPUT -p tcp --dport 50070 -j ACCEPT

Visual Studio 2012 Web Publish doesn't copy files

Had the same problem recently in VS 2013 for a MVC project in which I imported Umbraco CMS. I couldn't publish. The answer above helped, though I needed a while to figure out what I actually should do in VS. It needed some research e.g. on MS blogs to find out. I try to say it simple:

  • Choose in the VS toolbar a certain configuration e.g. Release and Any CPU. Run the project.
  • Afterwards right-click in the Solution Explorer on the solution in question, choose Publish. Create a new publishing profile or use a given one, but always make sure that in the settings the same configuration (e.g. Release and Any CPU) is chosen, as before you run the project the last time.
  • Additionally in my case it was necessary to delete the OBJ folder because here the settings from my last unsuccessful tries to publish got stuck, though I restarted VS and deleting all publishing profiles.

Excel Validation Drop Down list using VBA

The accepted answer is correct but needs to be wary that this way imposes a 255 character limit. Better to reference an actual worksheet range object.

Pytorch reshape tensor dimension

import torch
>>>a = torch.Tensor([1,2,3,4,5])
>>>a.size()
torch.Size([5])
#use view to reshape

>>>b = a.view(1,a.shape[0])
>>>b
tensor([[1., 2., 3., 4., 5.]])
>>>b.size()
torch.Size([1, 5])
>>>b.type()
'torch.FloatTensor'

What is the best Java QR code generator library?

QRGen is a good library that creates a layer on top of ZXing and makes QR Code generation in Java a piece of cake.

What does "commercial use" exactly mean?

Fundamentally if you use it as part of a business then its commercial use - so its not a matter of whether the tools are directly generating income or not rather one of if they are being used in support of income generation directly or indirectly.

To take your specific example, if the purpose of the site is to sell or promote your paid services/product then its a commercial enterprise.

SQL Server Profiler - How to filter trace to only display events from one database?

By experiment I was able to observe this:

When SQL Profiler 2005 or SQL Profiler 2000 is used with database residing in SQLServer 2000 - problem mentioned problem persists, but when SQL Profiler 2005 is used with SQLServer 2005 database, it works perfect!

In Summary, the issue seems to be prevalent in SQLServer 2000 & rectified in SQLServer 2005.

The solution for the issue when dealing with SQLServer 2000 is (as explained by wearejimbo)

  1. Identify the DatabaseID of the database you want to filter by querying the sysdatabases table as below

    SELECT * 
    FROM master..sysdatabases 
    WHERE name like '%your_db_name%'   -- Remove this line to see all databases
    ORDER BY dbid
    
  2. Use the DatabaseID Filter (instead of DatabaseName) in the New Trace window of SQL Profiler 2000

Calculate relative time in C#

I got this answer from one of Bill Gates' blogs. I need to find it on my browser history and I'll give you the link.

The Javascript code to do the same thing (as requested):

function posted(t) {
    var now = new Date();
    var diff = parseInt((now.getTime() - Date.parse(t)) / 1000);
    if (diff < 60) { return 'less than a minute ago'; }
    else if (diff < 120) { return 'about a minute ago'; }
    else if (diff < (2700)) { return (parseInt(diff / 60)).toString() + ' minutes ago'; }
    else if (diff < (5400)) { return 'about an hour ago'; }
    else if (diff < (86400)) { return 'about ' + (parseInt(diff / 3600)).toString() + ' hours ago'; }
    else if (diff < (172800)) { return '1 day ago'; } 
    else {return (parseInt(diff / 86400)).toString() + ' days ago'; }
}

Basically, you work in terms of seconds.

What does the "More Columns than Column Names" error mean?

Depending on the data (e.g. tsv extension) it may use tab as separators, so you may try sep = '\t' with read.csv.

Best C# API to create PDF

Update:

I'm not sure when or if the license changed for the iText# library, but it is licensed under AGPL which means it must be licensed if included with a closed-source product. The question does not (currently) require free or open-source libraries. One should always investigate the license type of any library used in a project.


I have used iText# with success in .NET C# 3.5; it is a port of the open source Java library for PDF generation and it's free.

There is a NuGet package available for iTextSharp version 5 and the official developer documentation, as well as C# examples, can be found at itextpdf.com

Append values to query string

The end to all URL query string editing woes

After lots of toil and fiddling with the Uri class, and other solutions, here're my string extension methods to solve my problems.

using System;
using System.Collections.Specialized;
using System.Linq;
using System.Web;

public static class StringExtensions
{
    public static string AddToQueryString(this string url, params object[] keysAndValues)
    {
        return UpdateQueryString(url, q =>
        {
            for (var i = 0; i < keysAndValues.Length; i += 2)
            {
                q.Set(keysAndValues[i].ToString(), keysAndValues[i + 1].ToString());
            }
        });
    }

    public static string RemoveFromQueryString(this string url, params string[] keys)
    {
        return UpdateQueryString(url, q =>
        {
            foreach (var key in keys)
            {
                q.Remove(key);
            }
        });
    }

    public static string UpdateQueryString(string url, Action<NameValueCollection> func)
    {
        var urlWithoutQueryString = url.Contains('?') ? url.Substring(0, url.IndexOf('?')) : url;
        var queryString = url.Contains('?') ? url.Substring(url.IndexOf('?')) : null;
        var query = HttpUtility.ParseQueryString(queryString ?? string.Empty);

        func(query);

        return urlWithoutQueryString + (query.Count > 0 ? "?" : string.Empty) + query;
    }
}

How to use OpenSSL to encrypt/decrypt files?

DO NOT USE OPENSSL DEFAULT KEY DERIVATION.

Currently the accepted answer makes use of it and it's no longer recommended and secure.

It is very feasible for an attacker to simply brute force the key.

https://www.ietf.org/rfc/rfc2898.txt

PBKDF1 applies a hash function, which shall be MD2 [6], MD5 [19] or SHA-1 [18], to derive keys. The length of the derived key is bounded by the length of the hash function output, which is 16 octets for MD2 and MD5 and 20 octets for SHA-1. PBKDF1 is compatible with the key derivation process in PKCS #5 v1.5. PBKDF1 is recommended only for compatibility with existing applications since the keys it produces may not be large enough for some applications.

PBKDF2 applies a pseudorandom function (see Appendix B.1 for an example) to derive keys. The length of the derived key is essentially unbounded. (However, the maximum effective search space for the derived key may be limited by the structure of the underlying pseudorandom function. See Appendix B.1 for further discussion.) PBKDF2 is recommended for new applications.

Do this:

openssl enc -aes-256-cbc -pbkdf2 -iter 20000 -in hello -out hello.enc -k meow

openssl enc -d -aes-256-cbc -pbkdf2 -iter 20000 -in hello.enc -out hello.out

Note: Iterations in decryption have to be the same as iterations in encryption.

Iterations have to be a minimum of 10000. Here is a good answer on the number of iterations: https://security.stackexchange.com/a/3993

Also... we've got enough people here recommending GPG. Read the damn question.

How to test if a file is a directory in a batch script?

If your objective is to only process directories then this will be useful.

This is taken from the https://ss64.com/nt/for_d.html

Example... List every subfolder, below the folder C:\Work\ that has a name starting with "User":

CD \Work
FOR /D /r %%G in ("User*") DO Echo We found

FOR /D or FOR /D /R

@echo off
cd /d "C:\your directory here"
for /d /r %%A in ("*") do echo We found a folder: %%~nxA
pause

Remove /r to only go one folder deep. The /r switch is recursive and undocumented in the command below.

The for /d help taken from command for /?

FOR /D %variable IN (set) DO command [command-parameters]

If set contains wildcards, then specifies to match against directory names instead of file names.

Calculate days between two Dates in Java 8

Use the class or method that best meets your needs:

  • the Duration class,
  • Period class,
  • or the ChronoUnit.between method.

A Duration measures an amount of time using time-based values (seconds, nanoseconds).

A Period uses date-based values (years, months, days).

The ChronoUnit.between method is useful when you want to measure an amount of time in a single unit of time only, such as days or seconds.

https://docs.oracle.com/javase/tutorial/datetime/iso/period.html

How to create a file in memory for user to download, but not through server?

For me this worked perfectly, with the same filename and extension getting downloaded

<a href={"data:application/octet-stream;charset=utf-16le;base64," + file64 } download={title} >{title}</a>

'title' is the file name with extension i.e, sample.pdf, waterfall.jpg, etc..

'file64' is the base64 content something like this i.e, Ww6IDEwNDAsIFNsaWRpbmdTY2FsZUdyb3VwOiAiR3JvdXAgQiIsIE1lZGljYWxWaXNpdEZsYXRGZWU6IDM1LCBEZW50YWxQYXltZW50UGVyY2VudGFnZTogMjUsIFByb2NlZHVyZVBlcmNlbnQ6IDcwLKCFfSB7IkdyYW5kVG90YWwiOjEwNDAsIlNsaWRpbmdTY2FsZUdyb3VwIjoiR3JvdXAgQiIsIk1lZGljYWxWaXNpdEZsYXRGZWUiOjM1LCJEZW50YWxQYXltZW50UGVyY2VudGFnZSI6MjUsIlByb2NlZHVyZVBlcmNlbnQiOjcwLCJDcmVhdGVkX0J5IjoiVGVycnkgTGVlIiwiUGF0aWVudExpc3QiOlt7IlBhdGllbnRO

Initializing a member array in constructor initializer

How about

...
  C() : arr{ {1,2,3} }
{}
...

?

Compiles fine on g++ 4.8

Create table using Javascript

<style>
    body{
        background: radial-gradient(rgba(179,255,0.5),rgba(255,255,255,0.5),rgba(0,0,0,0.2));
        text-align: center;
    }
    #name{
        margin-top: 50px;
    }
    .input{
        font-size: 25px;
        color: #004d00;
        font-weight: 700;
        font-family: cursive;
    }
    #entry{
        width: 150px;
        height: 40px;
        font-size: 23px;
        font-family:  cursive;
        background-color: #001a66;
        color: whitesmoke;
        box-shadow: 0 2px 2px 0 rgba(0,0,0,0.5);
        margin: 20px;
    }
    table{
        border-collapse: collapse;
        width: 50%;
        margin: 50px auto;
        background-color: burlywood;
    }
    table,th,td{
       border: 2px solid black;
       padding:5px;

    }
    th{
        font-size: 30px;
        font-weight: 700;
        font-family: Arial;
        color: #004d00;
    }
    td{
        font-size: 25px;
        color: crimson;
        font-weight: 400;
        font-family: Georgia;
    }
    .length{
        width: 20%;
    }
</style>
<body>
    <!-- Code to get student details -->
    <div id="container" >
        <div class="input">
             Name: <input type="text" id="name" class="length" placeholder="eg: Anil Ambani"/>
        </div>
        <div class="input">
             Email: <input type="text" id="mail" class="length" placeholder="eg: [email protected]"/>
        </div>
        <div class="input">
             Phone: <input type="text" id="phn"  class="length" placeholder="eg: 9898989898"/>
        </div>
        <div class="input">
             SLNO: <input type="number" id="sln" class="length" placeholder="eg: 1"/>
        </div>
        <br>
        <button id="entry"> I/P ENTRY</button>
    </div>
    <table id="tabledata">
       <tr>
          <th> Name</th>
          <th> Email</th>
          <th> Phone</th>
          <th> Slno</th>
       </tr> 
    </table>
</body>
<script>
    var entry = document.getElementById('entry');
    entry.addEventListener("click",display);
    var row = 1;
    function display(){
        var nam =  document.getElementById('name').value;
        var emal = document.getElementById('mail').value;
        var ph = document.getElementById('phn').value;
        var sl = document.getElementById('sln').value;
        var disp = document.getElementById("tabledata");
        var newRow = disp.insertRow(row);
        var cell1 = newRow.insertCell(0);
        var cell2 = newRow.insertCell(1);
        var cell3 = newRow.insertCell(2);
        var cell4 = newRow.insertCell(3);
        cell1.innerHTML = nam;
        cell2.innerHTML = emal;
        cell3.innerHTML = ph;
        cell4.innerHTML = sl;
        row++;
    }
</script>

How to serve all existing static files directly with NGINX, but proxy the rest to a backend server.

If you use mod_rewrite to hide the extension of your scripts, or if you just like pretty URLs that end in /, then you might want to approach this from the other direction. Tell nginx to let anything with a non-static extension to go through to apache. For example:

location ~* ^.+\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|pdf|txt|tar|wav|bmp|rtf|js|flv|swf|html|htm)$
{
    root   /path/to/static-content;
}

location ~* ^!.+\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|pdf|txt|tar|wav|bmp|rtf|js|flv|swf|html|htm)$ {
    if (!-f $request_filename) {
        return 404;
    }
    proxy_set_header X-Real-IP  $remote_addr;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_pass http://127.0.0.1:8080;
}

I found the first part of this snippet over at: http://code.google.com/p/scalr/wiki/NginxStatic

Retrieving a List from a java.util.stream.Stream in Java 8

In case someone (like me) out there is looking for ways deal with Objects instead of primitive types then use mapToObj()

String ss = "An alternative way is to insert the following VM option before "
        + "the -vmargs option in the Eclipse shortcut properties(edit the "
        + "field Target inside the Shortcut tab):";

List<Character> ll = ss
                        .chars()
                        .mapToObj(c -> new Character((char) c))
                        .collect(Collectors.toList());

System.out.println("List type: " + ll.getClass());
System.out.println("Elem type: " + ll.get(0).getClass());
ll.stream().limit(50).forEach(System.out::print);

prints:

List type: class java.util.ArrayList
Elem type: class java.lang.Character
An alternative way is to insert the following VM o

JavaScript Nested function

Functions are another type of variable in JavaScript (with some nuances of course). Creating a function within another function changes the scope of the function in the same way it would change the scope of a variable. This is especially important for use with closures to reduce total global namespace pollution.

The functions defined within another function won't be accessible outside the function unless they have been attached to an object that is accessible outside the function:

function foo(doBar)
{
  function bar()
  {
    console.log( 'bar' );
  }

  function baz()
  {
    console.log( 'baz' );
  }

  window.baz = baz;
  if ( doBar ) bar();
}

In this example, the baz function will be available for use after the foo function has been run, as it's overridden window.baz. The bar function will not be available to any context other than scopes contained within the foo function.

as a different example:

function Fizz(qux)
{
  this.buzz = function(){
    console.log( qux );
  };
}

The Fizz function is designed as a constructor so that, when run, it assigns a buzz function to the newly created object.

jQuery get the rendered height of an element?

style = window.getComputedStyle(your_element);

then simply: style.height

Simple conversion between java.util.Date and XMLGregorianCalendar

You can use the this customization to change the default mapping to java.util.Date

<xsd:annotation>
<xsd:appinfo>
    <jaxb:globalBindings>
        <jaxb:javaType name="java.util.Date" xmlType="xsd:dateTime"
                 parseMethod="org.apache.cxf.xjc.runtime.DataTypeAdapter.parseDateTime"
                 printMethod="org.apache.cxf.xjc.runtime.DataTypeAdapter.printDateTime"/>
    </jaxb:globalBindings>
</xsd:appinfo>

Concatenate a list of pandas dataframes together

Given that all the dataframes have the same columns, you can simply concat them:

import pandas as pd
df = pd.concat(list_of_dataframes)

Server configuration is missing in Eclipse

In my case, the server list was empty for Apache in "Run Configurations" when I opened

Run > Run Configurations enter image description here

I fixed this by creating a server in the Servers Panel as in other answers:

  1. Window -> Show view -> Servers
  2. Right click -> New -> Server : to create a new one

enter image description here

enter image description here

How do I set up CLion to compile and run?

You can also use Microsoft Visual Studio compiler instead of Cygwin or MinGW in Windows environment as the compiler for CLion.

Just go to find Actions in Help and type "Registry" without " and enable CLion.enable.msvc Now configure toolchain with Microsoft Visual Studio Compiler. (You need to download it if not already downloaded)

follow this link for more details: https://www.jetbrains.com/help/clion/quick-tutorial-on-configuring-clion-on-windows.html

error: unknown type name ‘bool’

C99 does, if you have

#include <stdbool.h> 

If the compiler does not support C99, you can define it yourself:

// file : myboolean.h
#ifndef MYBOOLEAN_H
#define MYBOOLEAN_H

#define false 0
#define true 1
typedef int bool; // or #define bool int

#endif

(but note that this definition changes ABI for bool type so linking against external libraries which were compiled with properly defined bool may cause hard-to-diagnose runtime errors).

Java substring: 'string index out of range'

I would recommend apache commons lang. A one-liner takes care of the problem.

pstmt2.setString(3, StringUtils.defaultIfEmpty(
    StringUtils.subString(itemdescription,0, 38), "_")); 

How to implement the Java comparable interface?

Emp class needs to implement Comaparable interface so we need to Override its compateTo method.

import java.util.ArrayList;
import java.util.Collections;


class Emp implements Comparable< Emp >{

    int empid;
    String name;

    Emp(int empid,String name){
         this.empid = empid;  
         this.name = name;

    }


    @Override
    public String toString(){
        return empid+" "+name;
    }

    @Override
    public int compareTo(Emp o) {

     if(this.empid==o.empid){
       return 0; 
     } 
     else if(this.empid < o.empid){
     return 1;
     }
     else{
       return -1;
     }
    }
}

public class JavaApplication1 {


    public static void main(String[] args) {

    ArrayList<Emp> a= new ArrayList<Emp>();

    a.add(new Emp(10,"Mahadev"));
      a.add(new Emp(50,"Ashish"));
      a.add(new Emp(40,"Amit"));
      Collections.sort(a);
      for(Emp id:a){
      System.out.println(id);
      }
    }

}

ImportError in importing from sklearn: cannot import name check_build

If you use Anaconda 2.7 64 bit, try

conda upgrade scikit-learn

and restart the python shell, that works for me.

Second edit when I faced the same problem and solved it:

conda upgrade scikit-learn

also works for me

What is the simplest method of inter-process communication between 2 C# processes?

The easiest solution in C# for inter-process communication when security is not a concern and given your constraints (two C# processes on the same machine) is the Remoting API. Now Remoting is a legacy technology (not the same as deprecated) and not encouraged for use in new projects, but it does work well and does not require a lot of pomp and circumstance to get working.

There is an excellent article on MSDN for using the class IpcChannel from the Remoting framework (credit to Greg Beech for the find here) for setting up a simple remoting server and client.

I Would suggest trying this approach first, and then try to port your code to WCF (Windows Communication Framework). Which has several advantages (better security, cross-platform), but is necessarily more complex. Luckily MSDN has a very good article for porting code from Remoting to WCF.

If you want to dive in right away with WCF there is a great tutorial here.

Register comdlg32.dll gets Regsvr32: DllRegisterServer entry point was not found

Information about missing entry point error installing legacy VB6 compiled applications on Windows 10 which I hope could be useful to someone.

Missing OCX files can be found in the "OS\System folder" of the Visual Basic 6.0 installer package. Today I copied the relevant OCX file (from our network) to the local computer

And then I typed the commands below, as administrator, which normally work to register it.

cd \windows\syswow64
regsvr32.exe /u mscomctl.ocx
regsvr32.exe /i mscomctl.ocx

(add the path to the locally copied file for the /i command)

However today I got errors from both these regsvr32.exe commands.

The second error was giving the DllImport missing entry point error which is similar to the error mentioned by the original poster.

To resolve, one of the things I tried was leaving out the switch -

regsvr32.exe mscomctl.ocx

To my surprise it then said it was successful. To confirm, the application started up properly afterwards.

ASP.NET MVC 3 - redirect to another action

You will need to return the result of RedirectToAction.

Oracle SQL query for Date format

you can use this command by getting your data. this will extract your data...

select * from employees where to_char(es_date,'dd/mon/yyyy')='17/jun/2003';

Convert nullable bool? to bool

You can use Nullable{T} GetValueOrDefault() method. This will return false if null.

 bool? nullableBool = null;

 bool actualBool = nullableBool.GetValueOrDefault();

Tool to convert java to c# code

For your reference:

Note: I had no experience on them.

Print a div content using Jquery

https://github.com/jasonday/printThis

$("#myID").printThis();

Great Jquery plugin to do exactly what your after

Excel CSV - Number cell format

Load csv into oleDB and force all inferred datatypes to string

i asked the same question and then answerd it with code.

basically when the csv file is loaded the oledb driver makes assumptions, you can tell it what assumptions to make.

My code forces all datatypes to string though ... its very easy to change the schema. for my purposes i used an xslt to get ti the way i wanted - but i am parsing a wide variety of files.

Convert object array to hash map, indexed by an attribute value of the Object

Using the spread operator:

const result = arr.reduce(
    (accumulator, target) => ({ ...accumulator, [target.key]: target.val }),
    {});

Demonstration of the code snippet on jsFiddle.

Spring Boot + JPA : Column name annotation ignored

you have to follow some naming strategy when you work with spring jpa. The column name should be in lowercase or uppercase.

@Column(name="TESTNAME")
private String testName;

or

@Column(name="testname")
private String testName;

keep in mind that, if you have your column name "test_name" format in the database then you have to follow the following way

@Column(name="TestName")
private String testName;

or

@Column(name="TEST_NAME")
private String testName;

or

@Column(name="test_name")
private String testName;

The EXECUTE permission was denied on the object 'xxxxxxx', database 'zzzzzzz', schema 'dbo'

In Sql Server Management Studio:

just go to security->schema->dbo.

Double click dbo, then click on permission tab->(blue font)view database permission and feel free to scroll for required fields like "execute".Help yourself to choose usinggrantor deny controls. Hope this will help:)

What is the correct syntax of ng-include?

For those who are looking for the shortest possible "item renderer" solution from a partial, so a combo of ng-repeat and ng-include:

<div ng-repeat="item in items" ng-include src="'views/partials/item.html'" />

Actually, if you use it like this for one repeater, it will work, but won't for 2 of them! Angular (v1.2.16) will freak out for some reason if you have 2 of these one after another, so it is safer to close the div the pre-xhtml way:

<div ng-repeat="item in items" ng-include src="'views/partials/item.html'"></div>

Oracle SQL - DATE greater than statement

you have to use the To_Date() function to convert the string to date ! http://www.techonthenet.com/oracle/functions/to_date.php

How to get Rails.logger printing to the console/stdout when running rspec?

For Rails 4.x the log level is configured a bit different than in Rails 3.x

Add this to config/environment/test.rb

# Enable stdout logger
config.logger = Logger.new(STDOUT)

# Set log level
config.log_level = :ERROR

The logger level is set on the logger instance from config.log_level at: https://github.com/rails/rails/blob/v4.2.4/railties/lib/rails/application/bootstrap.rb#L70

Environment variable

As a bonus, you can allow overwriting the log level using an environment variable with a default value like so:

# default :ERROR
config.log_level = ENV.fetch("LOG_LEVEL", "ERROR")

And then running tests from shell:

# Log level :INFO (the value is uppercased in bootstrap.rb)
$ LOG_LEVEL=info rake test

# Log level :ERROR
$ rake test

Altering user-defined table types in SQL Server

If you can use a Database project in Visual Studio, you can make your changes in the project and use schema compare to synchronize the changes to your database.

This way, dropping and recreating the dependent objects is handled by the change script.

How do I format date value as yyyy-mm-dd using SSIS expression builder?

Correct expression is

"source " + (DT_STR,4,1252)DATEPART( "yyyy" , getdate() ) + "-" +
RIGHT("0" + (DT_STR,4,1252)DATEPART( "mm" , getdate() ), 2) + "-" +
RIGHT("0" + (DT_STR,4,1252)DATEPART( "dd" , getdate() ), 2) +".CSV"