Ionic radio-group with Angular Reactive Forms - ionic-framework

Question

I'm working on a project in Ionic and need to use reactive forms from Angular 5. I need to allow a user to select a language preference and I'm doing that with radio-group and ion-radio, but when I make changes to the form, I'm getting
ERROR Error: There is no FormControl instance attached to form control element with name: 'preferredLanguage'
Here is my template with the form
<ion-header>
<ion-navbar>
<ion-title>User Profile</ion-title>
</ion-navbar>
</ion-header>
<ion-content padding>
<form *ngIf="user" [formGroup]="profileForm" (ngSubmit)="saveUser()">
<ion-item>
<ion-label>Display Name</ion-label>
<ion-input type="text" formControlName="displayName"></ion-input>
</ion-item>
<ion-item>
<ion-label>First Name</ion-label>
<ion-input type="text" formControlName="firstName"></ion-input>
</ion-item>
<ion-item>
<ion-label>Last Name</ion-label>
<ion-input type="text" formControlName="lastName"></ion-input>
</ion-item>
<ion-item>
<ion-label>Email</ion-label>
<ion-input type="text" formControlName="email"></ion-input>
</ion-item>
<ion-item>
<ion-label>Street</ion-label>
<ion-input type="text" formControlName="street"></ion-input>
</ion-item>
<ion-item>
<ion-label>City</ion-label>
<ion-input type="text" formControlName="city"></ion-input>
</ion-item>
<ion-item>
<ion-label>State</ion-label>
<ion-input type="text" formControlName="state"></ion-input>
</ion-item>
<ion-item>
<ion-label>Zip Code</ion-label>
<ion-input type="text" formControlName="zip"></ion-input>
</ion-item>
<ion-list radio-group formControlName="preferredLanguage">
<ion-list-header>
Select Preferred Language
</ion-list-header>
<ion-item>
<ion-label>English</ion-label>
<ion-radio value="en-US"></ion-radio>
</ion-item>
<ion-item>
<ion-label>Spanish</ion-label>
<ion-radio value="es-US"></ion-radio>
</ion-item>
</ion-list>
<button type="submit" ion-button>Submit Profile</button>
</form>
</ion-content>
Here is my method that initializes the form
initProfileForm() {
this.profileForm = this.formBuilder.group({
displayName: [this.user.profile.displayName, Validators.required],
firstName: [this.user.profile.firstName, Validators.required],
lastName: [this.user.profile.lastName, Validators.required],
email: [this.user.profile.email, Validators.required],
street: [this.user.profile.street, Validators.required],
city: [this.user.profile.city, Validators.required],
state: [this.user.profile.state, Validators.required],
zip: [this.user.profile.zip, Validators.required] ,
preferredLanguage: [this.user.profile.preferredLanguage,
Validators.required]
});
}
Has anyone else had this issue and how did you solve it?

Answer 1

I ended up coming up with a solution. This blog helped me come up with an answer: https://robferguson.org/blog/2017/11/19/ionic-3-and-forms/ Apparently, radio-group doesn't work with formControlName so instead I ended up using this:
<ion-list radio-group [formControl]="profileForm.controls['preferredLanguage']">
<ion-list-header>
Select Preferred Language
</ion-list-header>
<ion-item>
<ion-label>English</ion-label>
<ion-radio value="en-US"></ion-radio>
</ion-item>
<ion-item>
<ion-label>Spanish</ion-label>
<ion-radio value="es-US"></ion-radio>
</ion-item>
</ion-list>
This fixed the issue so there is no longer an error.

Answer 2

Make some amendments in your HTML code:
<ion-item>
<ion-label>English</ion-label>
<ion-radio value="en-US" formControlName="preferredLanguage"></ion-radio>
</ion-item>
<ion-item>
<ion-label>Spanish</ion-label>
<ion-radio value="es-US" formControlName="preferredLanguage"></ion-radio>
</ion-item>
So basically instead of using it on parent use it individually for each radio button. This worked for me.
Hope it helps!

Answer 3

get preferredLanguage() {
return this.profileForm.get('preferredLanguage').value;
}
set preferredLanguage(ev: CustomEvent) {
this.profileForm.get('preferredLanguage').patchValue(ev.detail.value);
}
<ion-radio-group [value]="preferredLanguage" (ionChange)="preferredLanguage = $event">
<ion-item>
<ion-label>English</ion-label>
<ion-radio value="en-US"></ion-radio>
</ion-item>
<ion-item>
<ion-label>Spanish</ion-label>
<ion-radio value="es-US"></ion-radio>
</ion-item>
</ion-radio-group>