reactjs / reactjs/react.dev

useReducer dispatch flow clarification

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描述

Hi,

I've been looking around to try to find out more about the "dispatch / render" flow and can not find anything relevant yet.

My question is: when I do 2 dispatchsequentially such as:

dispatch({type: ACTION_1});
dispatch({type: ACTION_2});

Are we sure that the 2 actions will be processed before the next rendering cycle occurs?
Could it be that on the next rendering cycle, only ACTION_1 has been processed then ACTION_2 is processed on a later rendering cycle?

In other words, from the react perspective, is doing:

dispatch({type: ACTION_1});
dispatch({type: ACTION_2});

equivalent to:

dispatch({type: ACTIONS: payload: [ACTION_1, ACTION2]});

In a small demo, it seems that it doesn't matter:
https://codesandbox.io/s/tzp0s (see the console messages)

In my larger react app, it seems that often time there is a render cycle between 2 consecutive dispatch.

Is it considered an anti-pattern to do 2 dispatch sequentially and should we instead do 1 dispatch with the content of the 2 dispatch combined?

Thank you!

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研究方向

未指定文件或測試。首先在連結的 CodeSandbox 中重現循序 dispatch 行為,並將其與所描述的較大型應用程式行為進行比較;完成這項工作需要找到相關的 React 指南,並釐清 dispatch 與 render 之間的關係以及建議的用法。

由索引模型根據 Issue 內容生成。

評估

技術堆疊
javascript, react
領域
documentation, frontend
Issue 類型
文件
難度
4/5
預估耗時
3-5 天
活躍度
停滯
描述清晰度
需要釐清
新手友好度
35/100

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