Tutorial by Examples: ar

Once you have it on your app, just import it: import { AngularFireDatabase } from 'angularfire2/database'; constructor (private _af: AngularFireDatabase) {} With this Observable List you can access to a list of items under a path, for example if you have root/items/food you can get food items l...

hosts: mysql tasks: name: Add mysql user user: name: mysql shell: /sbin/nologin name: install the latest version of libselinux-python yum: name: libselinux-python state: latest name: install perl yum: name: perl state: latest name: remove the mysql-libs package y...

Steps to create MYSQL database Login to amazon account and select RDS service Select Launch DB Instance from the instance tab By defaul MYSQL Community Edition will be selected, hence click the select button Select the database purpose, say production and click next step Provide the mysql ver...

This post shows how to use most of the functions in the Regex class, work with null safely related to the Regex functions, and how raw strings makes it easier to write and read regex patterns. The RegEx class To work with regular expressions in Kotlin, you need to use the Regex(pattern: String) cl...

import { Injectable } from '@angular/core'; import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from '@angular/common/http'; import { UserService } from '../services/user.service'; import { Observable } from 'rxjs/Observable'; @Injectable() export class AuthHeaderInterceptor imple...

AttributeDescriptiononkeydownFires when a user is pressing a keyonkeypressFires when a user presses a keyonkeyupFires when a user releases a key

In this example we are going to implement spring-data-elasticsearch project to store POJO in elasticsearch. We will see a sample maven project which does the followings: Insert a Greeting(id, username, message) item on elasticsearch. Get All Greeting items which have been inserted. Update a Gr...

In this example we are going to see a maven based spring boot application which integrates spring-data-elasticsearch. Here, we will do the followings and see the respective code segments. Insert a Greeting(id, username, message) item on elasticsearch. Get all items from elasticsearch Update a s...

it can happen that you use a scanner with the System.in as parameter for the constructor, then you need to be aware that closing the scanner will close the InputStream too giving as next that every try to read the input on that (Or any other scanner object) will throw an java.util.NoSuchElementExcep...

For connection, here is a snippet to help you understand: //Allows you to enumerate and communicate with connected USB devices. UsbManager mUsbManager = (UsbManager) getSystemService(Context.USB_SERVICE); //Explicitly asking for permission final String ACTION_USB_PERMISSION = "com.android.e...

The npm scripts are commands that npm will run for you when called with the proper arguments. The power and sense of this is to NOT install the npm packages globally poluting your environment. The difference between pre-recognized and custom scripts relies on the run word between the tags, custom s...

Using Line Numbers ... and documenting them in case of error ("The importance of seeing Erl") Detecting which line raises an error is a substantial part of any debugging and narrows the search for the cause. To document identified error lines with a short description completes a successf...

Using arrow function as callback function can reduce lines of code. The default syntax for arrow function is () => {} This can be used as callbacks For example if we want to print all elements in an array [1,2,3,4,5] without arrow function, the code will look like this [1,2,3,4,5].forEach...