Optional Values

[fourgates]

Related to #609.

Is there any way to define a defaultValue as optional? I feel there are use cases where users would prefer the default value to be undefined instead of an empty string.

Angular uses generics to be able to type their forms. this allows you to infer types and set default values.

  private initForm(): any {
    return this.fb.group<Person>({
      personId: null,
      // hidden
      displayName: [{ value: null, disabled: true }],
      age: [{ value: null, disabled: true }],

      // personal info
      firstName: [null, Validators.compose([Validators.required, Validators.maxLength(100)])],
      middleName: [null, Validators.maxLength(100)],
      lastName: [null, Validators.compose([Validators.required, Validators.maxLength(100)])],
      legalFirstName: [null, Validators.maxLength(100)],
      legalLastName: [null, Validators.maxLength(100)],
      ...
   }

[crutchcorn]

You can do the same with injectForm by passing a generic:

injectForm<Person>()