MapperSelectors Extension

The MapperSelectors extension adds Controller#set_selectors, which sets selectors in the controller’s identity_map that ensure the fields returned from Controller#expanded_fields (from the FieldExpansion extension) are loaded for a given model when identity_map.load(model) is called.

This will allow the mapper to save DB work and bandwidth by selecting only the required database columns, and tracking only the relevant associations, necessary to satisfy the output fields of the request.

To use this extension, include it in a controller with include Praxis::Extensions::MapperSelectors. and define before callbacks on relevant actions that call set_selectors. For example:

before actions: [:index, :show] do |controller|