harry han harryhan24

Flutter

A quick cheatsheet of useful snippet for Flutter

Widget

A widget is the basic type of controller in Flutter Material. There are two type of basic Widget we can extend our classes: StatefulWidget or StatelessWidget.

Stateful

StatefulWidget are all the widget that interally have a dynamic value that can change during usage. It can receive an input value in the constructor or reference to functions. You need to create two classes like:

Setting up Docker with user namespaces on CentOS 7.4

The procedure below has been tested on a Digital Ocean VM with CentOS 7.4

# Install docker from RHEL’s standard repos
yum install -y docker

#
# We’ll activate the ‘user namespaces’ feature that defends against

	import { AbstractControl, FormArray, FormGroup } from '@angular/forms';
	import { map, toPairs, fromPairs, differenceWith, isEqual, isNull, isUndefined } from 'lodash';
	import { Observable, OperatorFunction, defer, empty, of, merge, pipe } from 'rxjs';
	import { distinctUntilChanged, filter, map, shareReplay, pairwise } from 'rxjs/operators';

	/**
	* Convenience RxJS operator that filters out undefined & null and modifies the downstream type
	* appropriately.
	*/
	export function exists<T>(): OperatorFunction<T \| undefined \| null, T> {

	11. Firebase – Remote Config(Change Value)
	● 원격으로 앱의 배경색, 프로레스 작동 및 종료가 가능합니다.

	1. 문서로 이동합니다. 원격 구성 탭으로 이동합니다.
	- compile 코드를 붙여넣습니다.
	- 작동 원리 부분의 mFirebaseRemoteConfig 코드를 가져옵니다. HomeActivity로 이동하여 remoteConfig() 메소드를 생성해 바디 부분으로 붙여넣습니다. 에러는 스스로 잡습니다.
	해당 코드는 디버깅 테스트를 할 때 에러를 잡아주는 기능입니다.

	- 문서 내 하단의 디폴트 설정 값을 입력하는 코드도 복사해 해당 메소드 하단에 붙여넣습니다.
	해당 코드는 서버에 해당되는 값이 없을 때 참조하는 기능입니다.

	const jsonResponse = require("../lib/jsonResponse");
	const asyncConcatService = require("../lib/asyncConcatService");

	module.exports.handler = async (event, context) => {
	let { a, b } = event.queryStringParameters;

	if (!a \|\| !b) {
	return jsonResponse.error({
	message: "Please specify 2 strings a and b to concatenate"
	});

	package com.your.package

	import android.app.Dialog
	import android.os.Bundle
	import com.your.package.R
	import com.google.android.material.bottomsheet.BottomSheetDialog
	import com.google.android.material.bottomsheet.BottomSheetDialogFragment

	/**
	* BottomSheetDialog fragment that uses a custom

	var AWS = require('aws-sdk')
	AWS.config.update({region: 'us-east-1'})
	const uuidV4 = require('uuid/v4')
	var translate = new AWS.Translate();
	var polly = new AWS.Polly();
	var s3 = new AWS.S3({
	params: {
	Bucket: 'YOURBUCKETNAME',
	}
	})

	sealed class Event {
	object One : Event()
	object Two : Event()
	data class Three(val int: Int) : Event()
	}

	inline fun <reified T : Any> T.ordinal() =
	T::class.java.superclass.classes.indexOfFirst { sub -> sub == this@ordinal::class.java }

	fun testOrdinal() {

	interface ApiService {

	@GET("api")
	fun getUsers(@Query("result") result: Int): Observable<RandomUserResponse>
	}

	/**
	* ANY
	*/
	fun Any.toJson(): String = GsonInitializer.toJson(this)

	/**
	* VIEW
	*/
	fun View.toggleVisibility(setAsVisible: Boolean) = if (setAsVisible) this.visible() else this.gone()