__zone_symbol__state: null, __zone_symbol__value: Array(0)

Ionic Framework ionic-v3
1

While i try to read any data as a value, i got __zone_symbol__state: null, __zone_symbol__value: Array(0) but when i check the storage there is an array.

this.storage.get("key").then((res)=>{console.log(res)})

Why could be reason

Thanks in advance

2

Wherever you get the “strange” __zone_symbol__state: null, __zone_symbol__value: Array(0), you are reading the promise, not the resolved value. If you experience this in a view…assign you res to a member of of your controller and bind the view to that value or use the | async pipe inside your view.

1 Like
3

The async pipe is for observables in this case, so that shouldn’t work.

But the rest of what is being said here is true.
storage.get returns a promise, not the value.
You’ll need to unwrap the promise in a .then

strorage.get('key')
.then( res => console.log(res));
3 Likes
4

Sure? https://angular.io/docs/ts/latest/api/common/index/AsyncPipe-pipe.html states “The async pipe subscribes to an Observable or Promise and returns the latest value it has emitted”

5

shows how little I use the async pipe :smile:

6

This is not first time i am using stroge .The last app which is done i used this syntax below and it works fine

storage.get("key").then((res)=>{console.log(res)})

and it was 2.2 ionic .

7

I Solved this

yes
it is really easy for start in you`re service create a function and then paste below text on that. for example i have a method to show PROFILE info in USER-STORAGE service

//read user to show in profile pages
//Iuser this my interface you can see on below
// this method return Promise
read_to_show_profile(): Promise {
return this.storage.get(user_storage_DB);
}

/ /
export interface Iuser {
id: string;
name: string;
mobileNumber: number;
city: string;
subCity: string;
galleryName: string;
imageSrc: string;
}
/ */

and then in you`re component u can import SERVICE and use it like below
MY.COMPONENT.TS file

public current_usr: Iuser = {};

constructor(
private storage_service: StorageUserService
) {}

ngOnInit() {
//read data from local storage and assign it to CURRENT_USER
this.storage_service.read_to_show_profile().then(result => {
this.current_usr = result;
console.log(this.current_usr);
});