javascript - 更新 redux 状态

Question

我试图让我的 redux reducers 在更新状态时更简单。例如，下面是一个 reducer :

const initialState = {
  emails: {
    id: {
      emailAddress: null,
      emailBody: null,
      emailSubject: null,
    },
  },
  calls: {},
};

function messaging(state = initialState, action) {
  switch (action.type) {
    case actionTypes.SET_EMAIL_ADDRESS:
      return {
        ...state,
        emails: {
          ...state.emails,
          [action.id]: {
            emailAddress: [action.emailAddress]
          },
        },
      };
    default:
      return state;
  }
}

export default messaging;

我试着写下面的 reducer，但是 webstorm 提示说这不是正确的表示法。我究竟做错了什么？此外，非常感谢任何有关如何以更清洁的方式更新状态的建议。谢谢!

case actionTypes.SET_EMAIL_ADDRESS:
  return {
    ...state,
    emails[action.id]: {
      ...state.emails[action.id],
      emailAddress: [action.emailAddress]
    },
  };

Answer 1

基于你的初始状态

并避免覆盖 emailBody 和 emailSubject 的现有值。

我会这样重写:

case actionTypes.SET_EMAIL_ADDRESS:
    const currentEmails = state.emails;
    const emailId = action.id;
    const emailAddress = action.emailAddress;

    const email = { ...currentEmails[emailId], emailAddress };
    const emails = { ...currentEmails, [emailId]: email };
    return { ...state, emails };

使用描述性名称总是值得的!