📚 Sorting by Delegated Attributes in CM Admin

CM Admin supports sorting on delegated or associated model attributes by specifying them in the sortable_columns configuration. This is particularly useful when you want to sort based on related models, such as organisation.name or cm_role.name.

✅ Prerequisites

Ensure that:

• The associated attributes are properly delegated in the model.

• Your database joins can support sorting on the associated table columns.

🛠 Example Setup

Given a model like:

# app/models/user.rb
class User < ApplicationRecord
  belongs_to :organisation
  belongs_to :cm_role

  delegate :name, to: :organisation, prefix: true, allow_nil: true
  delegate :name, to: :cm_role, prefix: true, allow_nil: true
end

In your CM Admin File:

# app/models/cm_admin/user.rb
sortable_columns [
  { column: 'created_at', display_name: 'Created At', default: true, default_direction: 'desc' },
  { column: 'updated_at', display_name: 'Updated At' },
  { column: 'first_name', display_name: 'Name' },
  { column: 'organisation_name', display_name: 'Organisation' },
  { column: 'cm_role_name', display_name: 'Role' }
]

🧠 Behind the Scenes

To support sorting via associations:

• CM Admin uses Arel or ActiveRecord joins and order clauses.

• The column name (e.g., organisation_name) should match a delegated method or virtual attribute on the model.

⚠️ Notes

• If you encounter SQL errors when sorting on these columns, you may need to explicitly define the join logic in your CM Admin controller or scope.

• If organisation_name or cm_role_name is not indexed or heavily queried, consider adding proper database indexes.