仅在使用 HOC 时查询组件中的元素类型错误

Question

我创建了一个 withInfiniteScroll 高阶组件，用于向简单的数据列表添加无限滚动。我正在尝试在 apollo 的 Query 组件中使用该 HOC。这是我收到元素错误的地方：

Uncaught Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

Check the render method of Query.

我也看到这个错误（不确定那是什么意思...）：

Uncaught (in promise) Error: ObservableQuery with this id doesn't exist: 3

当我不使用 HOC 时代码工作正常

<Query>
    {(data) => return <List list={data.list} /> }
</Query>

但是当我添加 HOC 时它坏了...

import withInfiniteScroll from './withInfiniteScroll';

const ListWithInfiniteScroll = withInfiniteScroll(List);

<Query>
    {(data) => return <ListWithInfiniteScroll list={data.list} /> }
</Query>

我很确定我没有混淆 default/named 进口。作为参考，这里是 HOC 实现（简化）：

const withInfiniteScroll = (Component) => {
    class WithInfiniteScroll extends React.Component {
        // Stuff here

        render() {
            return <Component {...this.props} />;
        }
    }
}

export default withInfiniteScroll;

Answer 1

尝试将数据传递到列表并在之后包装到 HOC 中，例如

import withInfiniteScroll from './withInfiniteScroll';

const ListWithData = (props) => (
  <Query>
    {(data) => return <List list={data.list} /> }
  </Query>
)

const ListWithInfiniteScroll = withInfiniteScroll(ListWithData);

Answer 2

在您的示例中，您似乎没有 return 在高阶组件函数中创建新的 class。因此，withInfiniteScroll(Component) 将 return 未定义。导致 Uncaught Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined.

试试这个：

const withInfiniteScroll = (Component) => {
    class WithInfiniteScroll extends React.Component {
        // Stuff here

        render() {
            return <Component {...this.props} />;
        }
    }

    // This line is important!
    return WithInfiniteScroll;
}

export default withInfiniteScroll;

您还可以删除粗箭头函数周围的括号以直接 return class，如下所示：

const withInfiniteScroll = Component => class extends React.Component { ... }

仅在使用 HOC 时查询组件中的元素类型错误

Element type error in Query component only when using a HOC

javascript

reactjs

apollo-client

higher-order-components