Tutorial by Examples

1.The Unit return type declaration is optional for functions. The following codes are equivalent. fun printHello(name: String?): Unit { if (name != null) println("Hello ${name}") } fun printHello(name: String?) { ... } 2.Single-Ex...

Replace firebase values with your app api values: import firebase from 'firebase'; componentWillMount() { firebase.initializeApp({ apiKey: "yourAPIKey", authDomain: "authDomainNAme", databaseURL: "yourDomainBaseURL", projectId: "yourProjectID", ...

When performing data science tasks, it’s common to want to use data found on the internet. You’ll usually be able to access this data via an Application Programming Interface(API) or in other formats. However, there are times when the data you want can only be accessed as part of a web page. In case...

While using scrollviews in storyboard it's better to calculate content size according to number of views present in scrollview rather than giving content size programatically with static value. Here are the steps to get content size dynamically. Step 1 : Add Scrollview to view in storyboard and ...

Starting from react-native version 0.38, a Jest setup is included by default when running react-native init. The following configuration should be automatically added to your package.json file: "scripts": { "start": "node node_modules/react-native/local-cli/cli.js ...

A simple OGL 4.0 GLSL shader program that shows that shows how to add details with tessellation shader to the geometry. The program is executed with a python script. To run the script, PyOpenGL and NumPy must be installed. The basic mesh in this example is an icosahedron that consists of 20 triang...

For better performance it's important to avoid using of array (lambda) function in JSX. As explained at https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-no-bind.md : A bind call or arrow function in a JSX prop will create a brand new function on every single render. Th...

It's highly recommended to use ESLint in your project on react-native. ESLint is a tool for code validation using specific rules provided by community. For react-native you can use rulesets for javascript, react and react-native. Common ESLint rules with motivation and explanations for javascript ...

The Xamarin Forms Entry control does not have a MaxLength property. To achieve this you can extend Entry as below, by adding a Bindable MaxLength property. Then you just need to subscribe to the TextChanged event on Entry and validate the length of the Text when this is called: class CustomEntry ...

Spread dot operator can be used instead of collect method (1..10)*.multiply(2) // equivalent to (1..10).collect{ it *2 } d = ["hello", "world"] d*.size() // d.collect{ it.size() }

Gpars offers intuitive ways to handle tasks concurrently import groovyx.gpars.* GParsPool.withPool { def result = dataList.collectParallel { processItem(it) } }

With the help of react-navigation, you can add navigation to your app really easy. Install react-navigation npm install --save react-navigation Example: import { Button, View, Text, AppRegistry } from 'react-native'; import { StackNavigator } from 'react-navigation'; const App = StackNavigat...

app.module.ts import {appStoreProviders} from "./app.store"; providers : [ ... appStoreProviders, ... ] app.store.ts import {InjectionToken} from '@angular/core'; import {createStore, Store, compose, StoreEnhancer} from 'redux'; import {AppState, default as reduce...

import * as Redux from 'redux'; import {Inject, Injectable} from '@angular/core'; @Injectable() export class exampleService { constructor(@Inject(AppStore) private store: Redux.Store<AppState>) {} getExampleState(){ console.log(this.store.getState().example); } } ...

import * as Redux from 'redux'; import {Inject, Injectable} from '@angular/core'; @Injectable() export class exampleService { constructor(@Inject(AppStore) private store: Redux.Store<AppState>) {} setExampleState(){ this.store.dispatch(updateExample("new value"...

app.store.ts import {InjectionToken} from '@angular/core'; import {createStore, Store, compose, StoreEnhancer} from 'redux'; import {AppState, default as reducer} from "../app.reducer"; export const AppStore = new InjectionToken('App.store'); const devtools: ...

MCVE's should start the Shiny app when they are copied in the console. An easy way to do this is using the shinyApp function. For example: why is my checkbox not responding? library(shiny) ui <- fluidPage( checkboxInput('checkbox', 'click me'), verbatimTextOutput('text') ) serv...

In practice, shiny Apps are often very complicated and full of features that have been developed over time. More often than not, those additional details are not necessary to reproduce your issue. It is best if you skip such details when writing MCVE's. WRONG Why is my plot not showing? libra...

The simplest way to include plots in your shinyApp is to use plotOutput in the ui and renderPlot in the server. This will work with base graphics as well as ggPlots library(shiny) library(ggplot2) ui <- fluidPage( plotOutput('myPlot'), plotOutput('myGgPlot') ) server <- function...