Searching Owner-Specific Tags in Rails with ActsAsTaggableOn and Ransack

Recently, I needed to implement a search feature for tags that are attached to specific owners using the ⁠acts_as_taggable_on gem in a Rails project. Since we use Ransack for searching, I wanted to integrate both tools. However, the standard documentation only covers searching tags without owners. If your tags are owner-specific, the default approach won’t work—so here’s how I solved it.

Here’s what I came up with:

class User < ActiveRecord::Base
  acts_as_tagger
end

class Photo < ActiveRecord::Base
  acts_as_taggable_on :locations
end

To add a new location tag to a photo, just use:

@some_user.tag(@some_photo, :with => "paris, normandy", :on => :locations)

This will create two records: one in the ⁠taggings table and one in the ⁠tags table.

To fetch the most recently added location tag for a photo:

Photo.last.taggings.last.tag.name

If you want to search for photos by location name, simply use:

taggings_tag_name_in: []

If your ⁠Photo model has multiple taggable contexts, you can specify the context as well:

taggings_context_eq: "locations"

So, your final Ransack query would look like this:

scope.ransack(taggings_tag_name_in: ["Barcelona"], taggings_context_eq: "locations").result

I hope this article helps you solve your tag-based search challenges with ⁠acts_as_taggable_on and Ransack. These gems are incredibly powerful when used together!