Ngx-formly: Get specific field's FormControl in hooks

[Carbammato]

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I'm trying to create a complex form, using field group and repeaters, flat and nested. Therefore, the formControl could be complicated a lot since there could be nested controls. But that's ok.

My problem is that I want to run some logic on the formControl of a specific field. E.g., adding a Subscription to the statusChange or valueChange. So I thought, since I'm using ngx-formly 5, I could try the hooks and using the formControl when the form has been created. So my field configuration might seem something like this:

fields: FormlyFieldConfig[] = [
    {
      key: 'repeater',
      type: 'repeat',
      templateOptions: {
        addText: 'Add',
      },
      fieldArray: {
        fieldGroup: [
          {
            className: 'col-sm-4',
            type: 'input',
            key: 'repeatedInput',
            hooks: {
                onInit:(field: FormlyFieldConfig) => {
                  // Here I need the formControl of the specific field, since something will happen here
                }
              },
            templateOptions: {
              label: 'Input:',
              required: true,
            },
          }
        ],
      },
    },
  ];

Current behaviour
the onInit has as argument a field: FormlyFieldConfig property with some information about the field and a sub-property called formControl which include the control of the entire structured form.

Desired behaviour
I'd like to be able to have a clean property containing the formControl of the selected field.

Since the formControl has a nested structure, I can navigate the tree. But If I have a repeater (like the structure posted above), I get a formArray, and I don't know how to get the formControl of (let's say) 4th repeatedInput inside the repeater field.

I might be missing something, so thank you for any help.
TL;DR: Is there a way to get the formControl as it is inside the hooks property of a specific field? If not, do you think could it be possible to have this feature?

Thanks in advance for any help.

[aitboudad]

I don't know how to get the formControl of (let's say) 4th repeatedInput inside the repeater field.

each field instance has a formControl and form instance which the parent form control, there is several ways to get the 4th repeatedInput, here is one of them:

hooks: {
  onInit:(field: FormlyFieldConfig) => {
    if (field.parent.key === '3') {
      console.warn(field.formControl);
    }
  }
},

[Carbammato]

@aitboudad thank you for your response, but this is not helping me at all, unfortunately, since I might need to get the n-th repeatedInput inside the repeatedField dinamically. Is there a way, to access to the FormArray from the child FormGroup knowing which index in the array has the child FormGroup assigned?

[aitboudad]

in the above example, you can get the FormArray and the FormGroup from the parent

field.parent.formControl // will return FormGroup
field.parent.form // will return FormArray

to access to the FormArray from the child FormGroup knowing which index in the array has the child FormGroup assigned?

field.parent.form.at(field.parent.key) // which will return the same result as `field.parent.formControl`