execute code inside subscribe on condition

Question

I have observable data in my angular2 app. The data has 2 properties

 {isFetching: false, user: {userID: 1, firstName: "john", lastName: "public"} }.

When the data is getting retrieved from server isFetching flag is true and user object is null. In one of my component I need to get some other data by userID that is on the observable object.Initially when the observable is subscribed user object is null. In my code I am having to check if the user is null before performing some other action. Below code works, but I think there has to be better way than having if condition inside subscribe block.

this.store.select<UserProfileState>('user')
        .subscribe(user => {
            if (!user.isFetching) {
              this.store.dispatch(this.informationPanelActions.loadInformationPanel(user.user.clientID, user.user.userID));
            }
        });

Any help is appreciated.

maxime1992 maxime1992 · Accepted Answer · 2016-12-02T08:00:48

As you're working with an Observable, you can use filter :

this.store.select<UserProfileState>('user')
    .filter(user => !user.isFetching)
    .subscribe(user => {
        this.store.dispatch(this.informationPanelActions.loadInformationPanel(user.user.clientID, user.user.userID));
    });

execute code inside subscribe on condition

1 Answers