[英]Using React Hooks useReducer, how can I update an object by ID efficiently?
I have a StackBlitz that you can fork, I found a similar answer but I'm having trouble applying it to my example, I think it's because I have an array of objects. 我有一个可以分叉的StackBlitz ,我找到了类似的答案,但是我在将其应用于示例时遇到了麻烦,我认为这是因为我有一组对象。
I have the code working but it's very verbose, and I would like something easier to read that others who use Redux will recognize. 我的代码可以正常工作,但是它很冗长,我想让使用Redux的其他人更容易理解。
const initialState = [];
const todoReducer = (state, action) => {
switch (action.type) {
case 'ADD_TODO': {
return [...state, {
id: state.length,
name: action.name,
complete: false
}];
}
case 'TOGGLE_COMPLETE': {
let left = state.filter((_, index) => index < action.index)
let right = state.filter((_, index) => index > action.index)
let completed = state.filter((_, index) => index == action.index)
let updatedItem = {
id: completed[0].id,
name: completed[0].name,
complete: !completed[0].complete
}
return [...left, updatedItem, ...right];
}
case 'CLEAR': {
return initialState;
}
default: {
return state;
};
}
}
I feel like the answer is is similar to this one? 我觉得答案类似于这个吗? Update array object in React Redux reducer
在React Redux Reducer中更新数组对象
In the answer I cited above, his object has state.posts
How can I update my example to be more like this one? 在上面引用的答案中,他的对象具有
state.posts
如何更新我的示例,使其更类似于此示例?
How can I target my Todos if I don't have a similar state object as I can't do something like: 如果我没有类似的状态对象,而又无法执行类似的操作,该如何定位待办事项:
state.todos.complete = false.
I want to write a better reducer for the 'COMPLETE' action. 我想为“ COMPLETE”动作写一个更好的reduce。 Do I need to modify how my state is structured, ie dopes it need to be an empty object instead of an array of objects?
我是否需要修改状态的结构,即是否需要将其作为一个空对象而不是对象数组?
Just map
: 只是
map
:
case 'TOGGLE_COMPLETE': {
return state.map((item, i) => i === action.index
? {...item, complete: !item.complete}
: item
)
}
You can conditionally update "complete" without iterating multiple times. 您可以有条件地更新“完成”而无需重复多次。
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