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最后一个子组件覆盖所有子组件

react-redux redux reactjs

dan-klasson · 技术社区 · 7 年前

我有一个包含3个子项的父组件:

<ChildComponent category="foo" />
<ChildComponent category="bar" />
<ChildComponent category="baz" />

子组件根据道具类别值调用api:

http://example.com/listings.json?category=foo

在我的操作中,数据按预期返回。但是,当子组件呈现数据时。最后一个子baz也在覆盖foo和bar中的值。

A. solution to this problem seems to be given here

我的 子组件 看起来像这样:

class TweetColumn extends Component {

  componentDidMount() {
    this.props.fetchTweets(this.props.column)
  }

  render() {
    const { tweets, column } = this.props
    if (tweets.length === 0) { return null }
    const tweetItems = tweets[column].map(tweet => (
      <div key={ tweet.id }>
        { tweetItems.name }
      </div>
    )
    return (
      <div className="box-content">
        { tweetItems }
      </div>
    )
  }
}

TweetColumn.propTypes = {
  fetchTweets: PropTypes.func.isRequired,
  tweets: PropTypes.array.isRequired
}

const mapStateToProps = state => ({
  tweets: state.tweets.items
})

export default connect(mapStateToProps, { fetchTweets })( TweetColumn )

还原剂

export default function tweetReducer(state = initialState, action) {
  switch (action.type) {
    case FETCH_TWEETS_SUCCESS:
      return {
    ...state,
    [action.data[0].user.screen_name]: action.data
      }
    default:
      return state;
  }
}

export default combineReducers({
    tweets: tweetReducer,
})

行动:

export const fetchTweets = (column) => dispatch => {
  dispatch({ type: FETCH_TWEETS_START })
  const url = `${ TWITTER_API }/statuses/user_timeline.json?count=30&screen_name=${ column }`
  return axios.get(url)
    .then(response => dispatch({
      type: FETCH_TWEETS_SUCCESS,
      data: response.data
    }))
    .then(response => console.log(response.data))
    .catch(e => dispatch({type: FETCH_TWEETS_FAIL}))

}

1 回复 | 直到 7 年前

nebuler 7 年前

您每次都在进行api调用 TweetColumn 安装了。如果你有多个 state.tweets.items . 这是因为您正在发送相同的操作 FETCH_TWEETS_SUCCESS category (foo,bar,baz),我将用以下方式编写减速机:

export default function tweetReducer(state = initialState, action) {
  switch (action.type) {
    case FETCH_TWEETS_SUCCESS:
      return {
          ...state,
          [action.data.category]: action.data
      }
    default:
      return state;
  }
}

推文栏 组成部分:

class TweetColumn extends Component {

  componentDidMount() {
    this.props.fetchTweets(this.props.column)
  }

  render() {
    const { column } = this.props;
    const tweetItems = this.props.tweets[column].map(tweet => (
      <div key={ tweet.id }>
        { tweet.name }
      </div>
    )
    return (
      <div className="box-content">
        { tweetItems }
      </div>
    )
  }
}

const mapStateToProps = state => ({
  tweets: state.tweets
})

const mapDispatchToProps = dispatch => ({
  fetchTweets: column => dispatch(fetchTweets(column))
})

export default connect(
  mapStateToProps,
  mapDispatchToProps,
)( TweetColumn )

您必须进行一些验证以确保 tweets[column]