CODEWITHSUNDEEP
javascriptreactjs
Gayathri
Gayathri

Reputation: 1896

Reflect changes without refresh in React

I am trying to do a simple task, with an input box in which text is entered and on submit gets listed below. I am unaware of how to reflect changes without refresh.

App.js

  constructor(props){
    super(props);
    this.state={
     todoList:[]
    }
  }
  componentWillMount(){
   console.log("mounting app");
   axios.get('http://localhost:8888/todoitems').then((res)=>{
     this.setState({todoList: res.data});
   });
  }
  save=()=>{
   var data={
     name:this.refs.newvalue.value,
     status:'started'
   };
   axios.post('http://localhost:8888/todoitem',data).then((res)=>{
    console.log("data inserted is":data);
   });
  }
  render() {
   return (
    <div className="App">
      <input type="text" ref="newvalue"/>
      <button onClick={this.save}>Submit</button>
      <table>
        <tbody>
          {
           this.state.todoList.map(todo => (
               <TodoList 
                 key={todo.id} 
                 id={todo.id} 
                 name={todo.name} 
                 status={todo.status} 
                 click={this.update.bind(this,todo.id)}
               />
              )})
          }
        </tbody>
      </table>
    }

TodoList.js

 render() {
    return (
      <tr onClick={this.props.click}>
         <td>{this.props.id}</td>
         <td>{this.props.name}</td>
         <td>{this.props.status}</td>
      </tr>
    );
 }

By this, changes would be reflected only in refresh. But i need changes reflected instant. I tried with shouldcomponentupdate and componentwillupdate but i see nextProps as undefined.And i am naive on knowing how to proceed. Please favour.

Upvotes: 1

Views: 13660

Answers (2)

Prakash Sharma
Prakash Sharma

Reputation: 16472

If you are returning the data after saving them, then you can simply reflect the changes without refreshing by adding that returned data to state like this

save=()=>{
     var data={
      name:this.refs.newvalue.value,
      status:'started'
    }
     axios.post('http://localhost:8888/todoitem',data).then((res)=>{
       console.log("data inserted is":data);
       // When data is returned after successfull save
       // add that data to the "todoList" state.
       let todoList = [...this.state.todoList]
       todoList.push(data)
       // setting back the state will trigger a rerender and will show the changes on screen
       this.setState({todoList})
     })
  }

Upvotes: 3

dashton
dashton

Reputation: 2704

You want this bit of code to render a Todo component not a TodoList:

 {
   this.state.todoList.map(todo=>{
      return (
       <Todo key={todo.id} id={todo.id} name={todo.name} status={todo.status} click={this.update.bind(this,todo.id)}/>
      )

   });

Or just pass the array into TodoList and create Todo in there.

Upvotes: 0

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