Module: IntrospectiveGrape::Traversal

Included in:
API
Defined in:
lib/introspective_grape/traversal.rb

Instance Method Summary collapse

Instance Method Details

#find_leaf(routes, record, params) ⇒ Object 



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# File 'lib/introspective_grape/traversal.rb', line 33

def find_leaf(routes, record, params)
  return record unless routes.size > 1

  # For deeply nested routes we need to search from the root of the API to the leaf
  # of its nested associations in order to guarantee the validity of the relationship,
  # the authorization on the parent model, and the sanity of passed parameters.
  routes[1..].each do |r|
    if record && params[r.key]
      ref    = r.reflection
      record = record.send(ref.name).where( id: params[r.key] ).first if ref
    end
  end

  verify_record_found(routes, params, record)
  record
end

#find_leaves(routes, record, params) ⇒ Object

For deeply nested endpoints we want to present the record being affected, these methods traverse down from the parent instance to the child model associations of the deeply nested route.



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# File 'lib/introspective_grape/traversal.rb', line 7

def find_leaves(routes, record, params)
  # Traverse down our route and find the leaf's siblings from its parent, e.g.
  # project/#/teams/#/team_users ~> project.find.teams.find.team_users
  # (the traversal of the intermediate nodes occurs in find_leaf())
  return record if routes.size < 2 # the leaf is the root

  record = find_leaf(routes, record, params) || return

  assoc  = routes.last
  if assoc.many?
    leaves = record.send( assoc.reflection.name ).includes( default_includes(assoc.model) )
    verify_records_found(leaves, routes)
    leaves
  else
    # has_one associations don't return a CollectionProxy and so don't support
    # eager loading.
    record.send( assoc.reflection.name )
  end
end

#verify_record_found(routes, params, record) ⇒ Object

Raises:

  • (ActiveRecord::RecordNotFound) 


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# File 'lib/introspective_grape/traversal.rb', line 50

def verify_record_found(routes, params, record)
  return unless params[routes.last.key] && record.class != routes.last.model

  raise ActiveRecord::RecordNotFound.new("No #{routes.last.model.name} with ID '#{params[routes.last.key]}'")
end

#verify_records_found(leaves, routes) ⇒ Object

Raises:

  • (ActiveRecord::RecordNotFound) 


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# File 'lib/introspective_grape/traversal.rb', line 27

def verify_records_found(leaves, routes)
  return if (leaves.map(&:class) - [routes.last.model]).empty?

  raise ActiveRecord::RecordNotFound.new("Records contain the wrong models, they should all be #{routes.last.model.name}, found #{records.map(&:class).map(&:name).join(',')}")
end