How to get the LocalStorage value out of promise scope ionic 4

Ionic Framework ionic-v3
1

So can you please correct me if i am wrong …

//Its working fine
this.storage.get(‘user_id’).then((result) => {
console.log(result);
});
//its not working
this.storage.get(‘user_id’).then((result) => {

});

console.log(result);

2

Not sure what you’re asking here. Looks like there could be a syntax error?

Your console.log line is not within the promise callback, so it wouldn’t work in the second scenario.

3

Thanks for your reply @tumain this is my actual code
getstorage()
{
this.storage.get(‘user_id’).then((result) => {
console.log(result);
});
}

let value =this.getstorage();

//then my output is like this

  1. ZoneAwarePromise {__zone_symbol__state: null, __zone_symbol__value: Array(0)}

  2. __zone_symbol__state: true

  3. __zone_symbol__value: “5”

  4. proto: Object

then how can i get this value __zone_symbol__value: “5”

4

i prefer the async/await syntax for promises, it feels easier to read
the method needs to return some value if you are assigning it to a variable

async getStorage(): Proimise<any> {
    try {
        const result =  await this.storage.get('user_id');
        console.log(result);
        return result;
    }
    catch(e) { console.log(e) }
}

let value = this.getStorage();

alternatively, without async:

getStorage() {
    return this.storage.get('user_id').then((result) => {
        console.log(result);
        return result;
    });
}

let value = this.getStorage();

do either of these work?

1 Like
5

Thanks @jjdev Checked
Nope!
same output i got

ZoneAwarePromise {__zone_symbol__state: null, __zone_symbol__value: Array(0)}

__zone_symbol__state: true
__zone_symbol__value: “5”
proto: Object

6 
let value: any;

getStorage() {
    try { return await this.storage.get('user_id') }
    catch(e) { console.log(e) }
}

this.getStorage().then((result) => {
    if (result) {
        console.log(result);
        value = result;
    }
});

Here I have just returned the promise entirely, and handle the ‘then’ outside of the method.

I’m not sure why this isn’t working for you, I haven’t had many problems using localStorage this way

7

Thanks @jjdev I tried all your ways but only got this output

ZoneAwarePromise {__zone_symbol__state: null, __zone_symbol__value: Array(0)}

__zone_symbol__state: true
__zone_symbol__value: “5”
proto: Object

8

Anyone having a idea ???

9

Please try this,

let x = storage.get(‘user_id’)

1 Like
10

I would just double check here and make sure you have everything implemented properly

Storage docs

11

Try this.

var result: any;

this.storage.get(‘user_id’).then((data) => {
 result = data
});
console.log(result);
12

you do not use a promise value directly.
you either use it in it’s then/catch method with callback,
or use it with await inside async block.

you may learn more about async programming in javascript from this youtube video:

13

Could you find any answer? I have same issue, but only when I build the app with capacitor, on the browser works fine

14

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);
});