Overview

Gives some methods that can parse query string parameters into a set of criterias that Mongoid can use to perform actual queries in MongoDB databases for a given model.

http://github.com/vicentemundim/mongoid_query_string_interface

This is a gem, so you can install it by:

sudo gem install mongoid_query_string_interface

Or, if you are using rails, put this in your Gemfile:

gem 'mongoid_query_string_interface'

To use it, just extend Mongoid::QueryStringInterface in your document model:

class Document
  include Mongoid::Document
  extend Mongoid::QueryInterfaceString

  # ... add fields here
end

Then, in your controllers put:

def index
  @documents = Document.filter_by(params)
  # ... do something like render a HTML template or a XML/JSON view of documents
end

That's it! Now you can do something like this:

http://myhost.com/documents?tags.all=ruby|rails|mongodb&tags.nin=sql|java&updated_at.gt=2010-01-01&created_at.desc&per_page=10&page=3

This would get all documents which have the tags 'ruby', 'rails' and 'mongo', and that don't have both 'sql' and 'java' tags, and that were updated after 2010-01-01, ordered by descending created_at. It will return 10 elements per page, and the 3rd page of results.

You could even query for embedded documents, and use any of the Mongodb conditional operators:

http://myhost.com/documents?comments.author=Shrek

Which would get all documents that have been commented by 'Shrek'. Basically, any valid path that you can use in a Mongoid::Criteria can be used here, and you can also append any of the Mongodb conditional operators.

You can sort results by passing a order_by parameter this:

http://myhost.com/documents?order_by=created_at.desc

or

http://myhost.com/documents?order_by=created_at

Which is the same as:

http://myhost.com/documents?order_by=created_at.asc

To order by more than one field:

http://myhost.com/documents?order_by=created_at.desc|updated_at.desc

Check the specs for more use cases.

• Vicente Mundim: vicente.mundim at gmail dot com
• Wandenberg Peixoto: wandenberg at gmail dot com