Question

鉴于以下内容：

$cat src/Greeting.re
let component = ReasonReact.reducerComponent("Greeting");

type action =
 | Click;

type state = {
    count: int
};

let make = (_children) => {
  ...component,
  initialState: () => {count: 0},
  reducer: (action, state) =>
    ReasonReact.Update({count: state.count + 1}),
  render: (self) => {
     let message = "Clicked " ++ string_of_int(self.state.count) ++ "x";
        <div>
          <button
            onClick={_event => self.send(Click)}
          />
          {ReasonReact.stringToElement(message)}
        </div>
  }
};

我收到以下编译时错误：

  17 ┆ <div>
  18 ┆   <button
  19 ┆     onClick={_event => self.send(Click)}
  20 ┆   />
  21 ┆   {ReasonReact.stringToElement(message)}

  This record expression is expected to have type
    ReasonReact.componentSpec (state,  'a,  'b,  'c,  'd)
  The field send does not belong to type ReasonReact.self

ninja: build stopped: subcommand failed.
>>>> Finish compiling(exit: 1)

我不明白。有人可以解释错误是什么以及如何解决它？

Answer 1

您必须在let component = ReasonReact.reducerComponent("Greeting");声明之前放置make行，如下所示：

…
let component = ReasonReact.reducerComponent("Greeting");

let make = (_children) => {
  ...component,
  initialState: () => {count: 0},
…

这样做的原因是reducer元素的类型是根据其他类型（即state和action）推断出来的，所以它需要能够在声明它时“看到”它们

另外，对于记录，您应该在bsb输出中看到关于此的警告：

这是一个ReasonReact reducerComponent还是保留的组件道具？如果是，则声明状态，保留的道具或动作的类型在组件声明之后？将这些类型移到组件声明之上应解决此问题！

尝试再次运行npm run start以查看警告！

Answer 2

我有类似的问题，我解决了改变self.send与self.reduce，尝试改变：

 <button
        onClick={_event => self.send(Click)}
 />

在：

<button
  onClick=(self.reduce(_event => Click))
/>

我不确定，但也许self.reduce是旧API，所以可能我们有旧版本的东西

编辑：我只是将原因更新为“0.3.1”，现在使用send

ReasonReact编译时错误的`self.send`

2 个答案: