In our rails application, there is a model called Essay and another
called Tag. Essay ‘has_and_belongs_to_many’ tags. When a user CREATEs an
essay, he gives the text in a text field which corresponds to a database
column in the essays table. The _form.rhtml also provides a text area
that lets the user tag the essay with keywords. The text area does not
correspond directly to any single column in the essays table. The text
is parsed and used to populate the tags table and set relations between
the essay and the tags.
This works when I create a new essay. When I try to EDIT and essay, I
would like to see the previously entered tags. This means the Tags text
area should be pre-populated. How do I do this?