Module | CouchRest::Mixins::Views::ClassMethods |
In: |
lib/couchrest/mixins/views.rb
|
Deletes any non-current design docs that were created by this class. Running this when you‘re deployed version of your application is steadily and consistently using the latest code, is the way to clear out old design docs. Running it to early could mean that live code has to regenerate potentially large indexes.
Define a CouchDB view. The name of the view will be the concatenation of by and the keys joined by and
class Post # view with default options # query with Post.by_date view_by :date, :descending => true # view with compound sort-keys # query with Post.by_user_id_and_date view_by :user_id, :date # view with custom map/reduce functions # query with Post.by_tags :reduce => true view_by :tags, :map => "function(doc) { if (doc['couchrest-type'] == 'Post' && doc.tags) { doc.tags.forEach(function(tag){ emit(doc.tag, 1); }); } }", :reduce => "function(keys, values, rereduce) { return sum(values); }" end
view_by :date will create a view defined by this Javascript function:
function(doc) { if (doc['couchrest-type'] == 'Post' && doc.date) { emit(doc.date, null); } }
It can be queried by calling Post.by_date which accepts all valid options for CouchRest::Database#view. In addition, calling with the :raw => true option will return the view rows themselves. By default Post.by_date will return the documents included in the generated view.
Calling with :database => [instance of CouchRest::Database] will send the query to a specific database, otherwise it will go to the model‘s default database (use_database)
CouchRest::Database#view options can be applied at view definition time as defaults, and they will be curried and used at view query time. Or they can be overridden at query time.
Custom views can be queried with :reduce => true to return reduce results. The default for custom views is to query with :reduce => false.
Views are generated (on a per-model basis) lazily on first-access. This means that if you are deploying changes to a view, the views for that model won‘t be available until generation is complete. This can take some time with large databases. Strategies are in the works.
To understand the capabilities of this view system more completely, it is recommended that you read the RSpec file at spec/core/model_spec.rb.