n-to-m relationships in Forms

That's easy enough:

Controller:

def edit
@movie = Movie.find(params[:id])
@languages = Language.find(:all)
end

View:

<label>Languages:</label><br/>
       <% @languages .each do |lang| %>
          <%= check_box_tag 'movie[language_ids][]', lang.id,
@movie.languages.include?(lang), :id=>"cb_#{lang.name}" %>
          <label for="cb_<%=lang.name%>"
class="inline"><%=lang.name%></label><br/>
       <% end %>

The trick is in the "movie[language_ids][]". Nothing else to do, just
do the standard Movie.new(params[:movie]) stuff in your controller and
everything should be fine.

Cheers
Max

Max, you rock. I create forms like this all the time, and I kept thinking that there must be a better way - and lo and behold, there is.