Pass state to recursively nested component in Reac

问题:

I have a component that has children of the same type as the component itself. I can render the children as well but the children can't seem to access their slice of state. I'm using React with Redux

export class Material extends React.Component {

  constructor(props) {
    super(props)
    this.renderChild = this.renderChild.bind(this)
    this.getNestedItems = this.getNestedItems.bind(this)
  }

  static propTypes = {
    parentId: PropTypes.number,
    id: PropTypes.number.isRequired,
    name: PropTypes.string.isRequired,
    subtext: PropTypes.string.isRequired,
    childIds: PropTypes.arrayOf(PropTypes.number.isRequired),
    fileType: PropTypes.string.isRequired
  }

  // This is where I am having trouble.
  // Shouldn't the props be accessible from state itself?

  renderChild = (id, childId) => (
      <Material key={childId}
        id={childId}
        parentId={id}
        name={name}
        subtext={subtext}
        fileType={fileType}
        />
    )

  getNestedItems = (id, childIds) => {
    console.log("id: " + id)
    console.log("childIds: " + childIds)
    var childItems = []
    for(var i=0; i < childIds.length; i++){
        var child = this.renderChild(id, childIds[i])
        childItems.push(child)
    }
    return childItems
  }

  render(){

    let childItems = []
    if(this.props.childIds){
      childItems = this.getNestedItems(this.props.id, this.props.childIds)
    }

    return(
      <ListItem
        leftAvatar={<Avatar icon={fileType.length === 0 ? <FileFolder /> : <ActionAssignment />} />}
        rightIcon={fileType.length === 0 ? <AddCircle /> : <ActionInfo />}
        primaryText={name}
        secondaryText={subtext}
        initiallyOpen={fileType.length === 0} // fileType is empty if it is a folder
        primaryTogglesNestedList={fileType.length === 0}
        nestedItems={childItems} // one has to pass an array of elements
      />
    )
  }
}

const mapStateToProps = (state, ownProps) => {
  return {
    id: ownProps.id,
    name: state.Material[ownProps.id].name,
    subtext: state.Material[ownProps.id].subtext,
    childIds: state.Material[ownProps.id].childIds,
    fileType: state.Material[ownProps.id].fileType,
  }
}

export default connect(
  mapStateToProps
)(Material)

Also, I'm making use of ListItem from Material-ui (these are ultimately rendered inside a List component) and my code is heavily influenced from the tree-view example in the official redux repo. My state looks like this:

const initialState = {
  0: {
      id: 0,
      name: 'Root',
      subtext: 'Some subtext',
      fileType: '',
      childIds: [1]
    },
  1: {
      id: 1,
      name: 'Child',
      subtext: 'Child subtext',
      fileType: 'png',
      childIds: []
    }

}

The state shown has the same structure as in the tree-view example

回答1:

Well, if I understand it right, you want these Material components to get it's data from the redux store.
If that's what you want to achieve you need to provide access to the redux's store to each one of the Material. Basically you need to wrap all of them with the connect HOC.
Example:

const MaterialContainer = connect(mapStateToProps)(Material);

And inside the renderChild function you would use this MaterialContainer.

renderChild = (id) => (
  <MaterialContainer key={childId} id={childId} />
)

You can see it working here https://jsbin.com/taquke/edit?js,output