CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3tagsacts-as-taggable-on
jay
jay

Reputation: 12495

Return all tags based on context - ActsAsTaggableOn

I'm using the rails gem acts-as-taggable on, and am tagging posts on two contexts: tags and topics.

To return a hash of all the topics tags used so far for posts I can use the code:

 Post.tag_counts_on(:topics)

However, I have created a certain number of set topics tags, and if some of these topics tags aren't currently being used as tags on posts, then the code above doesn't return the said topics.

I am wondering if there is a way to return all the relevant tags based on context -- I was hoping for a solution along the lines of :

 topics = Tag.topics

To implement the solution, I created a Tag.rb model: 

 class Tag < ActiveRecord::Base
   has_many :relationship_topics, :foreign_key => "topic_followed_id", :dependent => :destroy
   has_many :topic_followers, :through => :relationship_topics, :source => :topic_follower
 end

Here I have some code to allow for following topics, but nothing more.

Does anyone know how I could return all the tags based on context?

Upvotes: 10

Views: 4399

Answers (4)

Nadiya
Nadiya

Reputation: 1527

The method is very simple:

ActsAsTaggableOn::Tag.for_context('topics')

Upvotes: -1

Abram
Abram

Reputation: 41954

This worked best for me:

ActsAsTaggableOn::Tag.includes(:taggings).where(taggings:{context:'topics'}).uniq(:name).order(:name)

One limitation when doing joins or includes with a tagging context is that you will only see topics that are active. You cannot load up a topic list and have them show up using this query. See examples:

Without tagging context

2.2.1 :009 > ActsAsTaggableOn::Tag.includes(:taggings)
  ActsAsTaggableOn::Tag Load (0.4ms)  SELECT `tags`.* FROM `tags`
  ActsAsTaggableOn::Tagging Load (0.4ms)  SELECT `taggings`.* FROM `taggings` WHERE `taggings`.`tag_id` IN (1, 2, 3)
[
    [0] severe hearing loss {
                    :id => 1,
                  :name => "severe hearing loss",
        :taggings_count => 0
    },
    [1] hearing loss {
                    :id => 2,
                  :name => "hearing loss",
        :taggings_count => 1
    },
    [2] hearing aids {
                    :id => 3,
                  :name => "hearing aids",
        :taggings_count => 0
    }
]

With taggings context of topics

2.2.1 :016 > ActsAsTaggableOn::Tag.includes(:taggings).where(taggings:{context:'topics'})
  SQL (0.4ms)  SELECT `tags`.`id` AS t0_r0, `tags`.`name` AS t0_r1, `tags`.`taggings_count` AS t0_r2, `taggings`.`id` AS t1_r0, `taggings`.`tag_id` AS t1_r1, `taggings`.`taggable_id` AS t1_r2, `taggings`.`taggable_type` AS t1_r3, `taggings`.`tagger_id` AS t1_r4, `taggings`.`tagger_type` AS t1_r5, `taggings`.`context` AS t1_r6, `taggings`.`created_at` AS t1_r7 FROM `tags` LEFT OUTER JOIN `taggings` ON `taggings`.`tag_id` = `tags`.`id` WHERE `taggings`.`context` = 'topics'
[
    [0] hearing loss {
                    :id => 2,
                  :name => "hearing loss",
        :taggings_count => 1
    }
]

Upvotes: 0

cgenco
cgenco

Reputation: 3567

Use Model.tag_counts (from Using acts-as-taggable-on how do I find the top, say 10, tags in my app?):

User.skill_counts # => [<Tag name="joking" count=2>,<Tag name="clowning" count=1>...]

Upvotes: 0

rubish
rubish

Reputation: 10907

I have never used acts-as-taggable-on but a quick browse through of the code suggests, you can do:

# to get all the tags with context topic with counts
ActsAsTaggableOn::Tagging.
    includes(:tag).
    where(:context => "topics").
    group("tags.name").
    select("tags.name, COUNT(*) as count")

You should probably take a look at ActsAsTaggableOn::Tagging, ActsAsTaggableOn::Tag and the migration file in your db/migrations folder to figure out how you can go about it.

If you don't want the count, only the tag names:

tags = ActsAsTaggableOn::Tag.includes(:taggings).
           where("taggings.context = 'topics'").
           select("DISTINCT tags.*")

# usage
tags.each {|tag| puts tag.name}

I hope that answers your question.

Upvotes: 17

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