saving a model with a through association

I can't seem to find any logical way of handling this situation I have created.

Heres the problem I have worked myself into.

On the create/update of a model, say post, one of the things it has associated with it is a list of tags. The tags are associated through a separate model of tags_to_posts. But I wanted to separate the tags by the word, then save them.

On the PostController.update function i do a split of the tags based on the spaces. So the submitted params get broken into an array based on each word. But the save of this always seems to mess up.

This is basically how the situation is set up.

Models:

class Post < ActiveRecord::Base   has_many :tags_to_post   has_many :tags, :through => :tags_to_post end

class Tag < ActiveRecord::Base   has_many :tags_to_post   has_many :posts, :through => :tags_to_post end

class Tags_to_post < ActiveRecord::Base   belongs_to :post   belongs_to :tag end

Edit.html.erb :

<fieldset>   <label>Tags</label>   <%= text_field_tag 'post[tags]', @post.tags.join(' '), :id => 'post_tags' %> </fieldset>

PostController def update     @post = Post.find(params[:id])

    params[:post][:tags] = params[:post][:tags].split

    respond_to do |format|       if @post.update_attributes(params[:post])         flash[:notice] = 'Post was successfully updated.'         format.html { redirect_to(@post) }         format.xml { head :ok }       else         format.html { render :action => "edit" }         format.xml { render :xml => @post.errors, :status => :unprocessable_entity }       end     end end

Anyone have any suggestions for a good way of getting this to work?

Any suggestions?

Last bump i guess then i'll just let it die