How to get and return stored data - StorageService?

Ionic Framework ionic-v3
1

Hello,

I’m new to Ionic. I want to get and return the stored data, but it looks like I need to use Promise to make this code work and I do not know how to use Promise. I appreciate anyone who can look at my code below and give me advise on how to make this code work properly:

Provider: storage-service.ts:
I’m able to store and output data, but I cannot return the data:

import {Injectable} from '@angular/core';
import { Storage } from '@ionic/storage';

@Injectable()
export class StorageService {

constructor(public storage: Storage){}

public storeData (data) {
     this.storage.set('data', data);
  }

public getStoredData() {
    	this.storage.get('data').then((val) => {
    	console.dir(val);  //****** this outputs the object.
            return val;  //***** this returns undefined
     });
}

}

my-page.ts:

import {StorageService} from "../../providers/storage-service";

constructor(public storageService: StorageService) {

        //***** this outputs undefined, what I'm doing wrong?
        console.dir(this.storageService.getStoredData());
}
1 Like
2

try this

public getStoredData() {
    return this.storage.get('data');
}
3

Thank you - this worked; however, the data that is returned is an object. I tried this code and it does not work:
let user_hash=this.storageService.getStoredData()[‘user_hash’];
I also tried this and it does not work:
let user_hash=this.storageService.getStoredData().user_hash;
Could you please help on how do I get the value of the object name: user_hash?

4

refer this link i hope you will get all your answer here

5

You need to make the getStoredData() function promise and then when calling it, use .then to get your data out.

Get Data Function

getStorage(key: string): Promise<any> {
    return this.storage.get(key);
  }

Retrieving it

this.storage.getStorage('uid').then(uid => {
      // you can do anything here. I used uid as example because I use firebase and this saves me calls.
});
6

Don’t forget that not key and value are strings. You’ll need to use JSON.parse

1 Like
7

They should be DOMString which returns a string type. You wouldn’t want to put object, array, and/or number as your key.

1 Like