define_schema for Active Resource

Signed-off-by: Joshua Peek <josh@joshpeek.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/activeresource/lib/active_resource/schema_definition.rb b/activeresource/lib/active_resource/schema_definition.rb
new file mode 100644
index 0000000000..abcbf3ba4e
--- /dev/null
+++ b/activeresource/lib/active_resource/schema_definition.rb
@@ -0,0 +1,58 @@
+require 'active_resource/exceptions'
+
+module ActiveResource # :nodoc:
+  class SchemaDefinition # :nodoc:
+
+    # attributes can be known to be one of these types. They are easy to
+    # cast to/from.
+    KNOWN_ATTRIBUTE_TYPES = %w( string integer float )
+
+    # An array of attribute definitions, representing the attributes that
+    # have been defined.
+    attr_accessor :attrs
+
+    # The internals of an Active Resource SchemaDefinition are very simple -
+    # unlike an Active Record TableDefinition (on which it is based).
+    # It provides a set of convenience methods for people to define their
+    # schema using the syntax:
+    #  define_schema do |s|
+    #    s.string :foo
+    #    s.integer :bar
+    #  end
+    #
+    #  The schema stores the name and type of each attribute. That is then
+    #  read out by the define_schema method to populate the actual
+    #  Resource's schema
+    def initialize
+      @attrs = {}
+    end
+
+    def attribute(name, type, options = {})
+      raise ArgumentError, "Unknown Attribute type: #{type.inspect} for key: #{name.inspect}" unless type.nil? || SchemaDefinition::KNOWN_ATTRIBUTE_TYPES.include?(type.to_s) 
+
+      the_type = type.to_s
+      # TODO: add defaults
+      #the_attr = [type.to_s]
+      #the_attr << options[:default] if options.has_key? :default
+      @attrs[name.to_s] = the_type
+      self
+    end
+
+    # The following are the attribute types supported by Active Resource
+    # migrations. 
+    # TODO:  We should eventually support all of these:
+    # %w( string text integer float decimal datetime timestamp time date binary boolean ).each do |attr_type|
+    KNOWN_ATTRIBUTE_TYPES.each do |attr_type|
+      class_eval <<-EOV
+        def #{attr_type.to_s}(*args)                                                # def string(*args)
+          options = args.extract_options!                                      #   options = args.extract_options!
+          attr_names = args                                                    #   attr_names = args
+                                                                               #
+          attr_names.each { |name| attribute(name, '#{attr_type}', options) }  #   attr_names.each { |name| attribute(name, 'string', options) }
+        end                                                                    # end
+      EOV
+
+    end
+
+  end
+end