adding collections contexts

app/models/collections/context.rb

+module Collections
+  class Context
+    attr_reader :from, :privacy
+  end
+end

app/models/collections/public_context.rb

+##
+# This class represents an specification for listing collections
+# The PublicContext class specify all collections with field privacy=public
+class Collections::PublicContext < Collections::Context
+
+  def initialize
+    @from = 'Collection'
+    @privacy = 'public'
+  end
+
+end
\ No newline at end of file

app/models/collections/user_context.rb

+class UserContext < Collections::Context
+
+  def initialize(user)
+    @user = user
+    @from = sprintf "select expand(in('BelongsTo')) from %s)", user.rid
+  end
+
+end
\ No newline at end of file

app/models/collections/user_private_context.rb

+##
+# This class represents an specification for listing collections
+# The PublicContext class specify all collections with field privacy=public
+class Collections::UserPrivateContext < Collections::UserContext
+
+  def initialize
+    @privacy = 'private'
+  end
+
+end
\ No newline at end of file

app/models/collections/user_public_context.rb

+##
+# This class represents an specification for listing collections
+# The PublicContext class specify all collections with field privacy=public
+class Collections::UserPublicContext < Collections::UserContext
+
+  def initialize
+    @privacy = 'public'
+  end
+
+end
\ No newline at end of file