在React.js中设置和重置状态

Question

I'm trying to build a section in my web page where there are four components displayed in a 2X2 grid. When you click one, the box expands to the center of the screen while the others fade out. I've got that part figured out by calling setState on a few different properties to toggle css classes.

What I'm having trouble with is resetting the state when a "close" button is kicked so that the boxes assume their original shape and opacity. I'm seeing a console.log from within the "handleCloseClick" function, so I know that it is wired property. No matter how I loop through the array of the state, I cannot change their properties back to their original state. Here's my code.

class Parent extends Component{
  constructor(){
    super();
    this.state = 
      attrs: {[{
        id: 1,
        expand: false,
        reduced: false,
        seeText: false
    }],
    [{
        id: 2,
        expand: false,
        reduced: false,
        seeText: false
    }],
    [{
        id: 3,
        expand: false,
        reduced: false,
        seeText: false
    }],
    [{
        id: 4
        expand: false,
        reduced: false,
        seeText: false
    }]}
    this.handleClick = this.handleClick.bind(this)
    this.handleCloseClick = this.handleClick.bind(this)
  }
  /*This function works*/
  handleClick(e){
    const array = this.state.attrs
    array.map(function(element){
      if(element.id === i){
        element.reduced = false;
        element.expand = true;
        element.seeText = true;
      }else{
        element.reduced = true;
      }
    })
    this.seState({attrs: array})
  }
  /*This function will console.log but will not setState of attrs*/
  handleCloseClick(){
    const newArray = this.state.attrs
    newArray.map(function(element(){
      element.expand = false;
      element.reduced = false;
      element.seeText = false;
    })
    this.setState(attrs: newArray})
  }
  render(){
    const newEls = this.state.attrs;
    return(
      {newEls.map(function(newEl, index)){
        return <Child key={index} onClick={this.handleClick(el)} onCloseClick={this.handleCloseClick()} />
      }
    )
  }
}

Please help! Why won't the damn state change back?!?!

Answer 1

There's a few issues... .map returns a new array, it doesn't change the existing state. So you need to assign it to a variable to see the changes.

Also, you have to return a value in .map , or use an "implicit" return ({ vs { .

 handleCloseClick(){ const newArray = this.state.attrs.map(element => ({ element.expand = false; element.reduced = false; element.seeText = false; })) this.setState(attrs: newArray}) } 

You can also move initial state into its own method, then use in the constructor and when you want to reset it...

  constructor() { ... this.state = this.initialState(); } close() { this.setState(this.initialState()); } initialState() { return { attrs: [ [{ id: 1, expand: false, reduced: false, seeText: false }], [{ id: 2, expand: false, reduced: false, seeText: false }], [{ id: 3, expand: false, reduced: false, seeText: false }], [{ id: 4 expand: false, reduced: false, seeText: false }]} ]} }