我正在尝试将 Ngxs 作为状态管理系统,并遇到了一个我似乎无法弄清楚的特定用例。在这个用例中,我使用了两个标准化对象(为了便于阅读,我删除了一些不必要的字段)。
export interface Section {
id: number;
sequence: number;
name: string;
subName: string;
totalQuestions: number;
completedQuestions: number;
selected: boolean;
questionFlows: QuestionFlow[];
}
export interface QuestionFlow {
id: number;
contractId: number;
parentId: number;
subSectionId: number;
path: string;
question: string;
type: string;
answer: string;
completed: boolean;
sequenceNumber: number;
selected: boolean;
questionFlows: QuestionFlow[];
}
这两个对象驻留在不同的商店中。一个 SectionStore 和一个 QuestionFlowStore。状态模型如下:
export class SectionsStateModel {
sections: { [id: number]: Section };
currentSection: Section;
}
export class QuestionFlowsStateModel {
questionFlows: { [id: number]: QuestionFlow };
currentQuestionFlow: QuestionFlow;
}
现在我想在 QuestionFlowsState 中创建一个选择器,它返回属于 currentSection 的每个 questionFlow。是否可以在位于 QuestionFlowState 内的选择器内获取 currentSection,而 currentSection 位于 SectionState 内?我已经尝试了下面的代码(有一个填充的商店)但没有成功。
import { SectionsStateModel } from './sections.state';
@State<QuestionFlowsStateModel>({
name: 'questionFlows',
defaults: {
questionFlows: {},
currentQuestionFlow: null
}
})
export class QuestionFlowsState {
@Selector()
static getQuestionFlowsArrayFromCurrentSection(
state: QuestionFlowsStateModel,
sectionState: SectionsStateModel
) {
const questionFlowsFromCurrentSection: QuestionFlow[] = [];
sectionState.currentSection.questionFlows.forEach(questionFlow => {
questionFlowsFromCurrentSection.push(state.questionFlows[+questionFlow]);
});
return questionFlowsFromCurrentSection;
}
}
如果问题中有任何遗漏/不清楚的地方,请告诉我。
编辑: 在与@Danny Blue 反复讨论之后,我们找到了添加父状态的解决方案,该状态将包含选择器所需数据的状态作为子状态(可以在@State 装饰器中设置)。要访问这些儿童商店的数据,您需要致电 state.. 并且一切顺利。下面是解决我的问题的最终代码。
import { State, Selector } from '@ngxs/store';
import { SectionsState } from './sections.state';
import { QuestionFlowsState } from './question-flows.state';
import { QuestionFlow } from '../../contract-details.model';
import { SectionsStateModel } from './sections.state';
import { QuestionFlowsStateModel } from './question-flows.state';
@State({
name: 'parent',
children: [SectionsState, QuestionFlowsState]
})
export class ParentState {
@Selector()
static getParentFlowsArrayFromCurrentSection(
state
) {
const questionFlowsFromCurrentSection: QuestionFlow[] = [];
state.sections.currentSection.questionFlows.forEach(questionFlow => {
questionFlowsFromCurrentSection.push(
state.questionFlows.questionFlows[+questionFlow]
);
});
return questionFlowsFromCurrentSection;
}
}