5

首先是我的 graphql 数据模型：

type Human {
  id: !String,
  name: !String,
  children: [Human]
}

我正在使用的唯一路由（中继路由配置）：

class extends Relay.Route {
  static queries = {
    human: () => Relay.QL`query RootQuery { viewer }`
  };
  static routeName = 'AppHomeRoute';
}

列表组件：

class HumanList extends Component {
  render() {
    let {children} = this.props.human;

    let subListsHTML = human ? children.map(child => (
      <HumanListItem key={child.id} human={child}/>
    )) : '';

    return <ul>{subListsHTML}</ul>;
  }
}

export default Relay.createContainer(HumanList, {
  fragments: {
    human: () =>  Relay.QL`
      fragment on Human {
        children {
          id,
          ${HumanListItem.getFragment('human')}
        }
      }
    `
  }
});

列表项组件：

class HumanListItem extends Component {
  state = {expanded: false};

  render() {
    let {human} = this.props;

    let sublistHTML = '';
    if (this.state.expanded) {
      sublistHTML = <ul><HumanList human={human}/></ul>;
    }

    return (
      <li>
        <div onClick={this.onClickHead.bind(this)}>{human.name}</div>
        {sublistHTML}
      </li>
    );
  }

  onClickHead() {
    this.props.relay.setVariables({expanded: true});
    this.setState({expanded: true});
  }

}

HumanListItem.defaultProps = {viewer: {}};

export default Relay.createContainer(HumanListItem, {

  initialVariables: {
    expanded: false
  },

  fragments: {
    human: (variables) =>  Relay.QL`
      fragment on Human {
        name,
        ${HumanList.getFragment('human').if(variables.expanded)}
      }
    `
  }

});

这对于根列表运行良好。但是，一旦我单击 ListItem 并展开它，我就会收到以下错误：

Warning: RelayContainer: Expected prop 'human' supplied 'HumanList' to be data fetched by Relay. This is likely an error unless you are purposely passing in mock data that conforms to the shape of this component's fragment.

我无法理解它，因为我传递的数据不是模拟的，而是由 Relay 直接获取的，这可以在 HumanList 组合中看到。

4

1 回答 1

10

该错误表明<HumanList>在其数据准备好之前正在呈现。

class HumanListItem extends Component {
  onClickHead() {
    this.props.relay.setVariables({expanded: true});
    this.setState({expanded: true});  // <-- this causes the component to re-render before data is ready
  }

您可以查看变量的当前值，而不是使用状态：

class HumanListItem extends Component {
  // no need for `state.expanded`

  render() {
    let {human} = this.props;

    let sublistHTML = '';
    if (this.props.relay.variables.expanded) {
      // `variables` are the *currently fetched* data
      // if `variables.expanded` is true, expanded data is fetched
      sublistHTML = <ul><HumanList human={human}/></ul>;
    }

    return (
      <li>
        <div onClick={this.onClickHead.bind(this)}>{human.name}</div>
        {sublistHTML}
      </li>
    );
  }

  onClickHead() {
    this.props.relay.setVariables({expanded: true});
    // no need for `setState()`
  }

}

HumanListItem.defaultProps = {viewer: {}};

export default Relay.createContainer(HumanListItem, {

  initialVariables: {
    expanded: false
  },

  fragments: {
    human: (variables) =>  Relay.QL`
      fragment on Human {
        name,
        ${HumanList.getFragment('human').if(variables.expanded)}
      }
    `
  }

});
于 2015-09-10T17:41:36.007 回答