On Fri, Apr 22, 2011 at 8:09 AM, Kevin Pang <[email protected]> wrote:
> This is a copy/paste from my question over at > StackOverflow<http://stackoverflow.com/questions/5750963/implementing-a-tagging-system-in-rails>so > feel free to answer there if you want some reputation. > > I'm trying to implement a tagging system in a Rails app similar to the one > StackOverflow uses (where users enter in tags in a freeform textbox). I'm > aware that there are gems that can do this, but I wanted to try to implement > it myself for the learning experience. I got it to work, but since I'm a > Rails newbie I'm concerned I'm not doing it the "right way". > > Here's my current implementation: > > def Post > attr_accessor :tag_names > > has_and_belongs_to_many :tags > > after_save :update_tags > > private > def update_tags > tags.delete_all > > if tag_names.to_s == '' > return > end > > tag_names.split(/,/).each do |tag_name| > tag_name.strip! > tag = Tag.find_or_create_by_name(tag_name) > > if !tags.exists?(tag.id) > tags << tag > end > end > end > end > > This makes it easy for me to set up the tags for a post since all I have to > do is set the "tag_names" attribute on my post object. When I save the post > object, the after_save event fires and executes my update_tags function > which then handles creating tags and linking the post to them. > > Are there any problems with my implementation? > > > You're deleting the tag records on every save. So other posts which belong to the tags you deleted would most probably throw an error when you try to access the tags (or will they silently update the the post's tags?). Anyway, you need to have access to the join table and delete the records created there instead of deleting the tag records when updating the post record. I don't know if it would improve performance, but instead of deleting all tags of the post, why not compare the post's current tags first and create/associate a tag to the post if it's not yet associated? > -- > You received this message because you are subscribed to the Google Groups > "Ruby on Rails: Talk" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/rubyonrails-talk?hl=en. > -- ------------------------------------------------------------- visit my blog at http://jimlabs.heroku.com -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
