Monday, October 14, 2013

Get the dot notation of a embedded Mongoid element

I needed to get the dot notation for embedded documents to perform queries using the given dot notation.

I could not find a "standard" way of doing just that, so here are some helper methods I use in a class. (Part of soon-to-come BoxCMS)

This Gist uses Mongoid metadata and reflect_on_all_associations, so it might break for newer versions of mongoid at some point.

Using dot notation queries in mongoid, makes it easy to dig for even the deepest "weird" embedded structures you might have.

Example of query:
»  Box::Page.where("rows.boxes.box_items.is_template_object" => false).first

Dot notations in mongodb are a powerful tool, but use it wisely unless you are indexing "more than you should".
Basic usage: Call dot_notation_for_element(embedded_element) to get the dot notation all the way up to the parent document, excluding the parent documents name/embedded name.