CODEWITHSUNDEEP
angularionic-framework
ChuChuwi
ChuChuwi

Reputation: 1060

Is there a way for html page to loads after retrieving data from ionic storage?

I got an error ERROR TypeError: Cannot read property 'name' of undefined

I have a service that retrieves data from the storage and a homepage that calls the service and displays the data.

storage.service.ts

async initilizeData() {
   this.data = await this.storage.get('myData')
}
getData() : MyData {
   return this.data
}

home.page.ts

data: MyData

async ngOnInit() {
   this.storageService.initializeData()
   this.data = this.storageService.getData()
   console.log(this.data)
}

home.page.html

<ion-text>{{data.name}}</ion-text>
<ion-text>{{data.amount}}</ion-text>

The console.log() inside ngOnInit() does log out the data for me but in the HTML page both data.name and data.amount seems to be undefined (I knew since when I put *ngIf="!data == null" around the code, the error disappeared.)

Thank you for all the answers :)

Upvotes: 2

Views: 458

Answers (1)

sebaferreras
sebaferreras

Reputation: 44659

One way to do that would be to wrap the data using an ngIf, like this:

<ng-container *ngIf="data">
  <ion-text>{{ data.name }}</ion-text>
  <ion-text>{{ data.amount }}</ion-text>
</ng-container>

The content won't be displayed until data is initialized.

Another way to avoid this would be by using the safe navigation operator, like this:

<ion-text>{{ data?.name }}</ion-text>
<ion-text>{{ data?.amount }}</ion-text>

In this case, Angular will not try to access data.name and data.amount if data is null or undefined. Please keep in mind that this approach will still render the ion-text elements, but they will be empty until data is initialized.

Upvotes: 2

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