Angular Ngrx选择器不发出新值
我试图在解析程序中重新加载页面时从服务器获取单个对象，但是在保存到存储区后，应该从存储区获取该对象的选择器不会发出新值。为什么呢？ 选择器中的日志被调用两次，第二次调用新值，但由于某些原因，它们不会在解析器中发出。 任何帮助都将不胜感激 我的减速器文件：Angular Ngrx选择器不发出新值,angular,ngrx,Angular,Ngrx,我试图在解析程序中重新加载页面时从服务器获取单个对象，但是在保存到存储区后，应该从存储区获取该对象的选择器不会发出新值。为什么呢？ 选择器中的日志被调用两次，第二次调用新值，但由于某些原因，它们不会在解析器中发出。 任何帮助都将不胜感激 我的减速器文件： export interface GroupState extends EntityState<Group> { topicsLoaded: { topic: string, coun
export interface GroupState extends EntityState<Group> {
topicsLoaded: {
topic: string,
count: number,
groupsLoaded: number
}[];
}
export const adapter = createEntityAdapter<Group>();
export const initialGroupState = adapter.getInitialState({
topicsLoaded: []
});
export const groupReducer = createReducer(
initialGroupState,
on(GroupActions.getTopicGroupsSuccess, (state, action) => {
let oldTopics;
let newTopics;
// Check if 1st batch of groups have already been loaded //
const oldGroupsLoaded = state.topicsLoaded.find(g => g.topic === action.topic);
if (!oldGroupsLoaded) {
// Add topic to group entity //
newTopics = [...state.topicsLoaded];
newTopics.push({
topic: action.topic,
count: action.count,
groupsLoaded: action.groupsLoaded
});
} else {
// Update group entity //
const index = [...state.topicsLoaded].indexOf(oldGroupsLoaded);
oldTopics = [...state.topicsLoaded];
oldTopics[index] = {
...state.topicsLoaded[index],
groupsLoaded: state.topicsLoaded[index].groupsLoaded + action.groupsLoaded
};
}
return adapter.addMany(action.groups,
{
...state,
topicsLoaded: oldGroupsLoaded ? oldTopics : newTopics
});
}),
on(GroupActions.getSingleGroupSuccess, (state, action) => {
const newTopicLoaded = [...state.topicsLoaded];
newTopicLoaded.push({
topic: action.group.topic,
count: action.count,
groupsLoaded: 1
});
return adapter.addOne(action.group, {
...state,
topicsLoaded: newTopicLoaded
});
})
);
export const {
selectAll,
} = adapter.getSelectors();
导出接口GroupState扩展EntityState{
主题：{
主题：字符串，
计数：数字，
groupsLoaded:编号
}[];
}
export const adapter=createEntityAdapter（）；
export const initialGroupState=adapter.getInitialState({
topicsLoaded:[]
});
export const groupReducer=createReducer(
初始组状态，
on（GroupActions.GetTopicGroupsAccess，（状态，操作）=>{
让老话题；
让新托皮克；
//检查是否已加载第一批组//
constOldGroupsLoaded=state.topicsloadded.find（g=>g.topic==action.topic）；
如果（！oldGroupsLoaded）{
//将主题添加到组实体//
newTopics=[…state.topicsloadded]；
推({
主题：action.topic，
count:action.count，
groupsLoaded:action.groupsLoaded
});
}否则{
//更新组实体//
const index=[…state.topicsloadded].indexOf（oldGroupsLoaded）；
oldTopics=[…state.topicsLoaded]；
旧主题[索引]={
…state.topicsLoaded[索引]，
groupsLoaded:state.topicsLoaded[index]。groupsLoaded+action.groupsLoaded
};
}
返回adapter.addMany（action.groups，
{
……国家，
加载的主题：旧组已加载？旧主题：新主题
});
}),
on（GroupActions.getSingleGroupSuccess，（状态，操作）=>{
const newTopicLoaded=[…state.topicsLoaded]；
纽托皮克洛德推({
主题：action.group.topic，
count:action.count，
组别：1
});
返回adapter.addOne（action.group{
……国家，
已加载主题：新主题已加载
});
})
);
出口常数{
选择全部，
}=adapter.getSelectors（）；
resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
const topic = route.queryParams['topic'];
const id = route.paramMap.get('id');
return this.store
.pipe(
select(isTopicLoaded, { topic }),
withLatestFrom(
this.store.pipe(select(selectTopicGroups, { topic })),
this.store.pipe(select(selectGroupById, { id }))
),
tap(([loaded, groups, group]) => {
if (!loaded && !this.isLoading) {
this.isLoading = true;
this.store.dispatch(GroupActions.getTopicGroups({ topic, pageNumber: 1, pageSize: 20 }));
this.store.dispatch(SpinnerActions.startSpinner());
}
/* On page refresh groups will not be loaded from the store
so we need to fetch that single group from server
*/
if (id && !group && !this.groupLoading) {
this.groupLoading = true;
this.store.dispatch(GroupActions.getSingleGroup({ groupId: id }));
}
console.log(loaded, groups, group);
}),
filter(([loaded, groups, group]) => {
if (id) {
return group !== undefined ? true : false;
} else {
return !!loaded;
}
}),
map(([loaded, groups, group]) => {
if (group) {
return true;
}
// Offer to create a group if the array is empty //
if (groups.length === 0) {
this.router.navigate(['/groups/create'], {
queryParams: {
empty: true,
topic
}
});
return false;
}
}),
first(),
finalize(() => {
this.isLoading = false;
this.groupLoading = false;
}));
}
}
export const selectGroupsState = createFeatureSelector<GroupState>('groups');
export const selectAllGroups = createSelector(
selectGroupsState,
fromGroups.selectAll
);
export const selectTopicGroups = createSelector(
selectAllGroups,
(groups, props) => {
const topic = props.topic;
return groups.filter(g => g.topic === topic);
}
);
export const isTopicLoaded = createSelector(
selectGroupsState,
(state, props) => {
const topic = props.topic;
return !!state.topicsLoaded.find(g => g.topic === topic);
}
);
export const selectGroupById = createSelector(
selectAllGroups,
(groups, props) => {
console.log(groups, props);
const id = props.id;
return groups.find(g => g._id === id);
}
);
export const totalGroups = createSelector(
selectGroupsState,
(state, props) => {
const topic = props.topic;
const group = state.topicsLoaded.find(g => g.topic === topic);
return group ? group.count : 0;
}
);
export const groupsAlreadyLoaded = createSelector(
selectGroupsState,
(state, props) => {
const topic = props.topic;
const group = state.topicsLoaded.find(g => g.topic === topic);
return group ? group.groupsLoaded : 0;
}
);