Question

当我使用文件A中定义的createSelector在文件B中执行Selector时，我几次遇到以下错误...显然是Selector中定义的undefined文件A尚未实例化，我收到Error: Selector creators expect all input-selectors to be functions, instead received the following types: [function, undefined] at getDependencies (http://localhost:3000/index.js:47281:11) [<root>] at Object.createSelector (http://localhost:3000/index.js:47299:24) [<root>] at Object.<anonymous> (http://localhost:3000/index.js:170074:45) [<root>] at __webpack_require__ (http://localhost:3000/index.js:20:30) [<root>] at Object.<anonymous> (http://localhost:3000/index.js:112827:10) [<root>] at __webpack_require__ (http://localhost:3000/index.js:20:30) [<root>] at Object.<anonymous> (http://localhost:3000/index.js:112838:20) [<root>] at __webpack_require__ (http://localhost:3000/index.js:20:30) [<root>] at Object.<anonymous> (http://localhost:3000/index.js:85408:17) [<root>] at __webpack_require__ (http://localhost:3000/index.js:20:30) [<root>] at Object.<anonymous> (http://localhost:3000/index.js:113264:18) [<root>] at __webpack_require__ (http://localhost:3000/index.js:20:30) [<root>] at Object.<anonymous> (http://localhost:3000/index.js:28456:10) [<root>] at __webpack_require__ (http://localhost:3000/index.js:20:30) [<root>]引用错误...

export interface State {
  accounts?: IDenormalizedAccount[];
  id?: AccountID;
}

由于我曾经遇到过这种情况，我的想法是其他人会有类似的问题，但搜索stackoverflow和互联网并没有产生任何有意义的东西......这让我相信我还没有另一个根本的误解......

档案状态（商店/帐户）

import * as reportStore from 'Store/report';

const rootExtractor: (applicationState: ApplicationStates) => accountStore.State = (applicationState: ApplicationStates) => {
  if (!applicationState.account) {
    throw new Error('Account state was null or undefined within the application ngrx store');
  }

  return applicationState.account;
};

export const accountsExtractor: (state: accountStore.State) => IDenormalizedAccount[] = (state: accountStore.State) => !!state.accounts ? state.accounts : [];
export const accountsSelector = createSelector(rootExtractor, accountsExtractor);

export const reportAccountsExtractor: (accounts: IDenormalizedAccount[], id: ReportID) => IDenormalizedAccount[] = (accounts: IDenormalizedAccount[], id: ReportID): IDenormalizedAccount[] => !!id ? accounts.filter((account: IDenormalizedAccount) => id === account.reportId) : [];
export const reportAccountsSelector: Selector<any, IDenormalizedAccount[]> = createSelector(accountsSelector, reportStore.reportIdSelector, reportAccountsExtractor);

文件A选择器（商店/帐户）

export interface State {
  reports: Report[];
  id?: ReportID;
}

文件B状态（存储/报告）

const rootExtractor: (applicationState: ApplicationStates) => reportStore.State = (applicationState: ApplicationStates) => {
  if (!applicationState.report) {
    throw new Error('Report state was null or undefined within the application ngrx store');
  }

  return applicationState.report;
};

export const reportIdExtractor: (state: reportStore.State) => ReportID = (state: reportStore.State): ReportID => !!state.id ? state.id : undefined;
export const reportIdSelector: Selector<any, ReportID> = createSelector(rootExtractor, reportIdExtractor);

文件B选择器（存储/报告）

reportStore.reportIdSelector

undefined（在显示的最后一行）当createSelector用来实例化reportAccountsSelector

时，文件A被标记为{{1}}

在过去，我已经在＆＃34; root＆＃34;之间移动或复制了一些州。在我的商店中的对象，但这不是干的 - 所以，为什么我的方法失败并且是否有更好的（正确的）方法来处理我想从应用商店的其他部分访问状态的情况？

ngrx重新选择Selector createSelector加载顺序（循环）依赖项

0 个答案: