In my App i need to check, if a user is allready in the local storage, befor i call my api. if the user is allready in the storage, i want to give back the old data and dont call the api again.
My problem is, that when i try to check the sotrage, my app calls the api to fast. I dondt understand why.
So i call my getUser methode, in this method i check the localstorage value and then i check the value.
Maybe there is a way to tait for the local storage data.
You need to use the Promise that is returned by the Storage.
this.storage.get(key).then((value) => {
this.alreadyHasThe(value);
}).catch((empty) => {
this.checkValue(empty);
});Yes i do this, but always the api is called, and the storage output comes later…
callApi(){
if(checkUser()){
return new Promise oldData;
} else {
return new Probime (api call blabla);
}
}`
So i alwasy get a false, and after the api is called, on the console i get the storage output wo is true…
callApi() {
return new Promise((resolve, reject) => {
if (user = checkUser()) {
resolve(user);
} else {
reject(false);
}
});
}
And on the receiving side (if it is split up in multiple functions): class.callApi().then(result => { /process/}).catch(no_result => {/* fetch*/});
You could also just call the function to fetch the user here in callApi() and resolve with new fetched data. (instead of rejecting it and handling it elsewhere.)
checkUser(tag) {
this.local.get('oldUser').then((result) => {
console.log(result);
if (result == tag) {
return true;
} else {
this.local.set('oldUser', tag);
return false;
}
});
}
And then
loadProfile(platform, region, tag) {
if(this.checkUser(tag)){
return Promise.resolve(this.profileData);
} else {
return new Promise(resolve => {
this.http.get(this.api + platform + '/' + region + '/' + tag + '/profile')
.map(res => res.json())
.subscribe(data => {
this.profileData = data;
resolve(this.profileData);
});
});
}
};I can see the problem. The http uses Observable. This is executed asyncronously.
You should use callback functions in your loadProfile, I suppose… or wait!
Maybe try this using ‘toPromise()’ and modified your code to return promise:
Can you explain me/change my code to do this?
Would be realy helpful 
checkUser(tag) {
return new Promise((resolve, reject) => {
this.local.get('oldUser').then((result) => {
console.log(result);
if (result == tag) {
resolve(true);
} else {
this.local.set('oldUser', tag);
reject(false); //thus we can use catch
}
});
});
}
loadProfile(platform, region, tag) {
this.checkUser(tag).then(() => {
return Promise.resolve(this.profileData); //why even return it?
}).catch(() => {
return this.http.get(this.api + platform + '/' + region + '/' + tag + '/profile')
.map(res => res.json())
.toPromise().then((data) => { //toPromise; might be the key to succes here!!
this.profileData = data;
return Promise.resolve(this.profileData); //why even return it?
});
});
};
let me know… i also added some comments because, maybe you do not need to return the promise in loadProfile? Because then the work is done, right?
Now i have the problem in my home.ts
“Error TS2339: Property ‘then’ does not exist on type ‘void’”
Oh, then you forgot to return the Promise!
loadProfile(platform, region, tag) {
return .......Now i recive only undefined values
I fixed it wit an sqlite solution.
Hello LolStats,
How you fixed your issue. I have the same prolem, i want to get user information in localstorage to load in form.
Please can you help ?
Regards,
I hope this link will help you