# Conditional field

#### Only `null` or a Field instance, are allowed conditional values!

## Example 1:

```php
public bool $someBoolean = true;

protected function fields()
{
    return [
       $this->someBoolean 
          ? Input::make('Conditional Field 1')->required() 
          : Input::make('Conditional Field 2')->required(),
    ];
}
```

## Example 2:

If the field depends on third party javascript libraries like FlatPickr (DatePicker field) or Trix.

You cannot switch visibility because the JS instance won't be destroyed, or the external script won't be loaded if the condition is false.

The way around it is to add class `hidden` to the field-root.

```php
DatePicker::make(__('Birthday'), 'birthday')
    ->rootAttr($this->someBoolean ? [] : [ 'class' => 'hidden' ], true)
    ->locale('en')
    ->placeholder('Select a date...')
    ->includeExternalScripts(),
```

### Observe:

When hiding fields with class `hidden`, the data properties will always exist in `$form_data` and `$validated_data`\
This is important in `onCreateModel()` and `onUpdateModel()`

You might want to filter out those properties when saving your component. Depending on the state of your condition. **Please see this issue for a detailed example**: <https://github.com/tanthammar/tall-forms/issues/105#issuecomment-1029088173>

## Example 3:

```php
protected function conditional()
{
    if ($this->something === "No") {
        return false; //the field will be omitted
    } else {
        return true; //the field will be included
    }
}

protected function fields()
{
    return [
        $this->conditional() 
            ? Input::make('Conditional Field')->required() 
            : null,
    ];
}
```

## Example 4:

```php
public bool $someBoolean = true;

protected function fields()
{
    return [
        $this->someMethod(),
    ];
}

protected function someMethod()
{
    if($this->someBoolean)) {
        return Input::make('Conditional Field')->required(); 
    } else {
        return null;
    }
}
```

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