Module: Protobuf::ActiveRecord::Scope::ClassMethods

Defined in:
lib/protobuf/active_record/scope.rb

Instance Method Summary collapse

Instance Method Details

#field_scope(field, options = {}) ⇒ Object

Define fields that should be searchable via ‘search_scope`. Accepts a protobuf field and an already defined scope. If no scope is specified, the scope will be the field name, prefixed with `by_` (e.g. when the field is :guid, the scope will be :by_guid).

Optionally, a parser can be provided that will be called, passing the field value as an argument. This allows custom data parsers to be used so that they don’t have to be handled by scopes. Parsers can be procs, lambdas, or symbolized method names and must accept the value of the field as a parameter.

Examples:

class User < ActiveRecord::Base
  scope :by_guid, lambda { |*guids| where(:guid => guids) }
  scope :custom_guid_scope, lambda { |*guids| where(:guid => guids) }

  # Equivalent to `field_scope :guid, :by_guid`
  field_scope :guid

  # With a custom scope
  field_scope :guid, :scope => :custom_guid_scope

  # With a custom parser that converts the value to an integer
  field_scope :guid, :scope => :custom_guid_scope, :parser => lambda { |value| value.to_i }
end



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# File 'lib/protobuf/active_record/scope.rb', line 43

def field_scope(field, options = {})
  scope_name = if options.include?(:scope)
                 options[:scope]
               else
                 # When no scope is defined, assume the scope is the field, prefixed with `by_`
                 :"by_#{field}"
               end
  searchable_fields[field] = scope_name

  searchable_field_parsers[field] = options[:parser] if options[:parser]
end

#model_scope ⇒ Object

Get an ARel relation to build off of. If we’re in Rails 4 we need to use ‘all` instead of `scoped`. :noapi:



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# File 'lib/protobuf/active_record/scope.rb', line 58

def model_scope
  ::ActiveRecord::VERSION::MAJOR >= 4 ? all : scoped
end

#parse_search_values(proto, field) ⇒ Object

:noapi:



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# File 'lib/protobuf/active_record/scope.rb', line 63

def parse_search_values(proto, field)
  value = proto.__send__(field)

  if searchable_field_parsers[field]
    parser = searchable_field_parsers[field]

    if parser.respond_to?(:to_sym)
      value = self.__send__(parser.to_sym, value)
    else
      value = parser.call(value)
    end
  end

  values = [ value ].flatten
  values.map!(&:to_i) if proto.class.get_field(field, true).enum?
  values
end

#search_scope(proto) ⇒ Object

Builds and returns a Arel relation based on the fields that are present in the given protobuf message using the searchable fields to determine what scopes to use. Provides several aliases for variety.

Examples:

# Search starting with the default scope and searchable fields
User.search_scope(request)
User.by_fields(request)
User.scope_from_proto(request)



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# File 'lib/protobuf/active_record/scope.rb', line 92

def search_scope(proto)
  search_relation = model_scope

  searchable_fields.each do |field, scope_name|
    next unless proto.respond_to_and_has_and_present?(field)

    unless self.respond_to?(scope_name)
      raise SearchScopeError, "Undefined scope :#{scope_name}."
    end

    search_values = parse_search_values(proto, field)
    search_relation = search_relation.__send__(scope_name, *search_values)
  end

  return search_relation
end

#searchable_field_parsers ⇒ Object

:noapi:



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# File 'lib/protobuf/active_record/scope.rb', line 115

def searchable_field_parsers
  @_searchable_field_parsers ||= {}
end

#searchable_fields ⇒ Object

:noapi:



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# File 'lib/protobuf/active_record/scope.rb', line 110

def searchable_fields
  @_searchable_fields ||= {}
end