Tutorial by Examples: st

Lifecycle method call in different states

This example serves as a complement to other examples which talk about how to use the lifecycle methods and when the method will be called. This example summarize Which methods (componentWillMount, componentWillReceiveProps, etc) will be called and in which sequence will be different for a componen...

React • React Component Lifecycle

Creating a custom template for Custom Post type book

To create a template for the single posts of our custom post type, we need to create a file called single-post_type_name.php where post_type_name is the name of our custom post type. For example, if our custom post type is called “Books”, we need to create a PHP file called single-book.php. Note th...

WordPress • Create Template for Custom Post Type

React Native - ListView with Firebase

This is what I do when I'm working with Firebase and I want to use ListView. Use a parent component to retrieve the data from Firebase (Posts.js): Posts.js import PostsList from './PostsList'; class Posts extends Component{ constructor(props) { super(props); this.state =...

react-native • Integration with Firebase for Authentication

Constructor dependency injection

The Constructor Dependency Injection requires parameters in the constructor to inject dependencies. So you have to pass the values when you create a new object. public class Example { private readonly ILogging _logging; public Example(ILogging logging) { this._logging = l...

asp.net-mvc • Dependency Injection

List all databases

show dbs or db.adminCommand('listDatabases') or db.getMongo().getDBNames()

MongoDB • Getting database information

List all collections in database

show collections or show tables or db.getCollectionNames()

MongoDB • Getting database information

Encoding/Decoding using Go structs

Let's assume we have the following struct that defines a City type: type City struct { Name string Temperature int } We can encode/decode City values using the encoding/json package. First of all, we need to use the Go metadata to tell the encoder the correspondence between the...

Go • JSON

Paging list items returned from a query

To simulate paging using REST you can do the following: Use the $skip=n parameter to skip the first n entries according to the $orderby parameter Use the $top=n parameter to return the top n entries according to the $orderby and $skip parameters. var endpointUrl = "/_api/lists('g...

sharepoint • REST Services

Define custom managers

Very often it happens to deal with models which have something like a published field. Such kind of fields are almost always used when retrieving objects, so that you will find yourself to write something like: my_news = News.objects.filter(published=True) too many times. You can use custom mana...

Django • Custom Managers and Querysets

Custom Listview comprises of rows that are designed as per the users needs.

For the layout above your customrow.axml file is as shown below <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_heigh...

Xamarin.Android • Custom ListView

Using MarkupExtension with Converters to skip recource declaration

Usually to use the converter, we have to define it as resource in the following way: <converters:SomeConverter x:Key="SomeConverter"/> It is possible to skip this step by defining a converter as MarkupExtension and implementing the method ProvideValue. The following example conve...

wpf • Value and Multivalue Converters

Use IMultiValueConverter to pass multiple parameters to a Command

It is possible to pass multiple bound values as a CommandParameter using MultiBinding with a very simple IMultiValueConverter: namespace MyProject.Converters { public class Converter_MultipleCommandParameters : MarkupExtension, IMultiValueConverter { public object Convert(object...

wpf • Value and Multivalue Converters

Basic webpage using bootstrap components

<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1">...

twitter-bootstrap • Getting started with twitter-bootstrap

Gentoo/Funtoo Installation

Elixir is available in main packages repository. Update the packages list before installing any package: emerge --sync This is one step installation: emerge --ask dev-lang/elixir

Elixir Language • Installation

Install Jekyll on Linux Mint 18

Install jekyll on Linux Mint 18 with the following steps: sudo apt install ruby sudo apt install build-essential sudo apt install ruby-dev sudo gem install jekyll

jekyll • Getting started with jekyll

Install Jekyll on Windows

Open a command prompt with Administrator access Install Chocolatey: @powershell -NoProfile -ExecutionPolicy Bypass -Command "iex ((new-object net.webclient).DownloadString('https://chocolatey.org/install.ps1'))" && SET PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin Close the comm...

jekyll • Getting started with jekyll

with_items - simple list

A with_items loop in ansible can be used to easily loop over values. - name: Add lines to this file lineinfile: dest=/etc/file line={{ item }} state=present with_items: - Line 1 - Line 2 - Line 3

ansible • Ansible: Looping

with_items - predefined list

You can also loop over a variable list. From vars: favorite_snacks: - hotdog - ice cream - chips and then the loop: - name: create directories for storing my snacks file: path=/etc/snacks/{{ item }} state=directory with_items: '{{ favorite_snacks }}' If you are using Ansible ...

ansible • Ansible: Looping

Nested loops

You can create nested loops using with_nested. from vars: keys: - key1 - key2 - key3 - key4 then the loop: - name: Distribute SSH keys among multiple users lineinfile: dest=/home/{{ item[0] }}/.ssh/authorized_keys line={{ item[1] }} state=present with_nested: - [ 'calvin...

ansible • Ansible: Looping

Decoupling ErrorHandlerAttribute registering from the service implementation

To decouple and reuse the same error logging code for all your services you need two boilerplate classes and tuck them away in a library somewhere. ErrorhandlerAttribute implementing IServiceBehavior. FaultErrorhandler implementing IErrorhandler which logs all the exceptions. [AttributeUsage(Attr...

wcf • Handling exceptions