CouchRest is based on CouchDB's couch.js test library, which I find to be concise, clear, and well designed. CouchRest lightly wraps CouchDB's HTTP API, managing JSON serialization, and remembering the URI-paths to CouchDB's API endpoints so you don't have to.
CouchRest is designed to make a simple base for application and framework-specific object oriented APIs. CouchRest is Object-Mapper agnostic, the parsed JSON it returns from CouchDB shows up as subclasses of Ruby's Hash. Naked JSON, just as it was mean to be.
Easy Install is moving to RubyForge, heads up for the gem.
The core of Couchrest is Heroku’s excellent REST Client Ruby HTTP wrapper. REST Client takes all the nastyness of Net::HTTP and gives is a pretty face, while still giving you more control than Open-URI. I recommend it anytime you’re interfacing with a well-defined web service.
The most complete documentation is the spec/ directory. To validate your
CouchRest install, from the project root directory run rake, or autotest
(requires RSpec and optionally ZenTest for autotest support).
Quick Start:
# with !, it creates the database if it doesn't already exist
@db = CouchRest.database!("http://127.0.0.1:5984/couchrest-test")
response = @db.save_doc({:key => 'value', 'another key' => 'another value'})
doc = @db.get(response['id'])
puts doc.inspect
Bulk Save:
@db.bulk_save([
{"wild" => "and random"},
{"mild" => "yet local"},
{"another" => ["set","of","keys"]}
])
# returns ids and revs of the current docs
puts @db.documents.inspect
Creating and Querying Views:
@db.save_doc({
"_id" => "_design/first",
:views => {
:test => {
:map => "function(doc){for(var w in doc){ if(!w.match(/^_/))emit(w,doc[w])}}"
}
}
})
puts @db.view('first/test')['rows'].inspect
CouchRest::Model has been deprecated and replaced by CouchRest::ExtendedDocument
CouchRest::ExtendedDocuments instances have 2 callbacks already defined for you:
create_callback, save_callback, update_callback and destroy_callback
In your document inherits from CouchRest::ExtendedDocument, define your callback as follows:
save_callback :before, :generate_slug_from_name
CouchRest uses a mixin you can find in lib/mixins/callbacks which is extracted from Rails 3, here are some simple usage examples:
save_callback :before, :before_method
save_callback :after, :after_method, :if => :condition
save_callback :around {|r| stuff; yield; stuff }
Check the mixin or the ExtendedDocument class to see how to implement your own callbacks.
Often, you will want to store multiple objects within a document, to be able to retrieve your objects when you load the document, you can define some casting rules.
property :casted_attribute, :cast_as => 'WithCastedModelMixin'
property :keywords, :cast_as => ["String"]
If you want to cast an array of instances from a specific Class, use the trick shown above ["ClassName"]
Views can return any sort of JSON encoded data you want, not just full documents as they are stored in the DB. If the objects returned from your view are defined by classes that inherit from ViewObject, then they will be instanciated correctly when the view is called using the casted_from class method.
class Parent < CouchRest::ExtendedDocument
property :children, :cast_as => ["Child"]
end
class Child < CouchRest::Response
include CouchRest::ViewObject
property :year_born
view_by :year_born
:map => "
function(){
if (doc['couchrest-type'] == 'Parent' && doc.tags) {
doc.child.forEach(function(child){
emit(child.year_born, child);
}}}"
end
Child.casted_from :year_born #[child_1, child_2, ...]