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How to pass the props when set ref for a component

this.map[col1][row1] = <MemoizedItem key={item} x={row1} y={col1} />
this.setState({ map: this.map })

This is my code, I’m put all the item in param map. and render by using:

renderItem() {

  return this.state.map.map((row) => {
    return row.map((item) => {
      return item;
    })
  })
}

Now, i’m trying to pass the props color in the item by this.state.map[0][0].props.color ='#fff' but not working, get an error ‘Cannot add property color, object is not extensible’, so is there any way to do that?

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Answer

you should not store components in component state You can just store the data in state like

let data = [{id:'row1', cols:[{id:'col1'}, {id:'col2'}]} , {...}, ...]
this.setState({
  map: data
})

and render it using your memoized component

renderItem() {

  return this.state.map.map((row, rowIndex) => {
    return row.cols.map((item,index) => {
//you can pass whatever you want to pass to the component
      return <MemoizedComponent key={rowIndex+index} x={item} y={row} yourprops={condition ? color1: color2} />
    })
  })
}

finally you can update data by setting state like

  let final = this.state.data.map(r => {
    if (r === 'your condition') {
      return Object.assign({}, r, {
        cols: r.cols.map(c => {
          if (c === 'your col condition') {
            return Object.assign({}, c, {
              changedProp: 'changedPropvalue',
            });
          } else {
            return c;
          }
        }),
      });
    }else{
      return r
    }
  });

...

this.setState({data:final})

so when the state updates the component rerendered

also make sure you use PureComponent as it will restrict rerenders to only changed items

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