login.component.ts

// login method
login() {
    // set params: password or imageUrl, depending on chosen loginMethod
    var params: any = {
        username: this.username
    };
    if(this.loginMethod === 'password') {
        params.password = this.password;
    }
    else {
        params.image = this.imageUrl;
    }

    // perform http call
    this.userRestService.login({
        username: this.username,
        password: this.password,
        image: this.imageUrl
    }).subscribe( data => {
        // on success set token and user data
        var token = data.token;
        this.auth.setToken(token);
        this.auth.setUser({username: this.username});
          
        // navigate to home page
        this.router.navigate(['/home']);
    });
}

// image changed handler for embedded components (image picker, camera snapshot)
imageChanged(data) {
    this.imageUrl = data;
    this.ref.detectChanges();
}