Adding a "title" field to video thumbnails in the Video Module

Question

I would like to attach a textfield field to the video field. How can I go about doing that programmatically?

How do you attach a field of a field?

Answer 1

You can use hook_form_alter(), there is no any built-in option to do that.

You can also use the Field collection module to create a new field collection with a text field, and the video field.

Provides a field-collection field, to which any number of fields can be attached.

A field collection is internally represented as an entity, which is embedded in the host entity. Thus, if desired field collections may be viewed and edited separately too.

Answer 2

You can implement hook_field_widget_form_alter() to add a #process function to the widget. This is what the Image field does in image_field_widget_form(), by adding image_field_widget_process() as #process function.

// Add all extra functionality provided by the image widget.
$elements[$delta]['#process'][] = 'image_field_widget_process';

If you need to save the content of the form field you add, and the field doesn't provide a database field to save it, there is nothing much you can do, until No hook_field_schema_alter() gets implemented for Drupal 7 too.