Class: ForestAdminDatasourceToolkit::Utils::FieldPath

Inherits:
Object
  • Object
show all
Defined in:
lib/forest_admin_datasource_toolkit/utils/field_path.rb

Constant Summary collapse

POLYMORPHIC_MANY_TO_ONE = 
'PolymorphicManyToOne'.freeze

Class Method Summary collapse

Class Method Details

.leaf_collection_names(collection, path) ⇒ Object

The collections whose column a path ends on — the ones a read permission applies to. Collections crossed on the way are joins, not read targets, so they are not returned.

Several names come back for a path ending on a polymorphic relation: it carries no discriminant, so any record may resolve to any of its targets and none can be ruled out. The list is empty for a polymorphic relation declaring no target at all, which the caller counts as denied — an empty list is a path that resolves to nothing, not a path that needs nothing.

A prefix naming no relation raises rather than falling back to collection. The caller pins the collection it asked about to readable, so falling back would turn "this path does not resolve" into "this path is allowed".

A path with no prefix at all is a column of collection itself, and so is allowed. Two customisations reach a related collection through one deliberately: import_field, and an add_field whose dependencies cross a relation, both register a root-level column that the operator and sorting layers rewrite into a relation path below this guard. Like a scope or a replace_search, they are the customer's own choice of what a role reaches through a column it can read.



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# File 'lib/forest_admin_datasource_toolkit/utils/field_path.rb', line 24

def self.leaf_collection_names(collection, path)
  index = path.index(':')

  return [collection.name] if index.nil?

  relation = relation_at(collection, path[0...index])

  return relation.foreign_collections if relation.type == POLYMORPHIC_MANY_TO_ONE

  leaf_collection_names(
    collection.datasource.get_collection(relation.foreign_collection),
    path[(index + 1)..]
  )
end