[Redux] Fetching Data on the Route change

We'll learn how to fire a async request when the route changes.

A Mock Server data:

/**/api/index.js * Created by Wanzhen on 7.6.2016.*/Import {v4} from' Node-uuid ';//This is a fake in-memory implementation of something//That would is implemented by calling a REST server.Const Fakedatabase={todos: [{id:v4 (), Text:' Hey ', Completed:true, }, {id:v4 (), Text:' Ho ', Completed:true, }, {id:v4 (), Text:' Let ' s go ', Completed:false,}],};const delay= (ms) = =NewPromise (resolve =SetTimeout (Resolve, MS)); Export Const Fetchtodos= (Filter) = =Delay () then (() = {        Switch(filter) { Case' All ':                returnFakedatabase.todos;  Case' Active ':                returnFakeDatabase.todos.filter (t =!)t.completed);  Case' Completed ':                returnFakeDatabase.todos.filter (t =t.completed); default:                Throw NewError (' Unknown filter: ${filter} '); }    });

We want to replace Localstorge with mock server data and so remove the Localstorge code:

//Configurestore.jsImport {CreateStore} from' Redux '; import Todoapp from'./reducers '; Const Addloggingtodispatch= (store) = ={Const Rawdispatch=Store.dispatch; //If Browser not support Console.group    if(!console.group) {returnRawdispatch; }    return(Action) ={console.group (action.type); Console.log ('%c prev state ', ' Color:gray ', Store.getstate ()); Console.log ('%c action ', ' Color:blue ', action); Const ReturnValue=Rawdispatch (action); Console.log ('%c next state ', ' Color:green ', Store.getstate ());        Console.groupend (Action.type); returnreturnvalue; };}; Const Configurestore= () + ={Const Store=CreateStore (Todoapp); //If in production does not log it    if(Process.env.NODE_ENV!== ' production ') {Store.dispatch=Addloggingtodispatch (store); }    returnstore;}; ExportdefaultConfigurestore;

We want to fetch data inside the component:VisibleTodoList.js.

The good place-to-fetch data is in ' Componentdidmount ' lifecycle:this would fetch the initial data, which only run once.

Thats not enough, we still need if the filter changes, it also need to fetch data, for so we can use another lifecycle ' Componentdidupdate '.

Import {Connect} from ' React-redux '; import {Toggletodo} from‘.. /actions '; import ToDoList from'./todolist '; import {withrouter} from' React-router '; import {Getvisibletodos} from‘.. /reducers '; import React, {Component} from' React '; import {Fetchtodos} from‘.. /api '; class Visibletodolist extends Component {//Fetch data when component MountComponentdidmount () {Fetchtodos ( This. Props.filter). Then (Todos)={Console.log ( This. Props.filter, Todos); })    }    //Check The filter props, when it changes, fetch data againcomponentdidupdate (prevprops) {if( This. Props.filter!==prevprops.filter) {Fetchtodos ( This. Props.filter). Then (Todos)={Console.log ( This. Props.filter, Todos); }}}}} render () {return (            <todolist {... This.props}/>)}}const Mapstatetoprops= (state, {params}) = ={Const filter= Params.filter | | ' All '; //Todos, filter would available in props    return{Todos:getvisibletodos (State, filter), filter,};};//re-assign the VisibletodolistVisibletodolist =withrouter (Connect (mapstatetoprops, {Ontodoclick:toggletodo}) (visibletodolist)); ExportdefaultVisibletodolist;

[Redux] Fetching Data on the Route change