note
	description: "Summary description for {CMS_NODE_STORAGE_I}."
	date: "$Date: 2015-01-27 19:15:02 +0100 (mar., 27 janv. 2015) $"
	revision: "$Revision: 96542 $"

deferred class
	CMS_NODE_STORAGE_I

feature -- Error Handling

	error_handler: ERROR_HANDLER
			-- Error handler.
		deferred
		end

feature -- Storage extension

	register_node_storage_extension (a_extension: CMS_NODE_STORAGE_EXTENSION [CMS_NODE])
			-- Register `a_extension' as extension to the node storage system.
		local
			tb: like node_storage_extensions
		do
			tb := node_storage_extensions
			if tb = Void then
				create tb.make_caseless (1)
				node_storage_extensions := tb
			end
			tb.force (a_extension, a_extension.content_type)
		end

	node_storage_extension (a_node: CMS_NODE): detachable CMS_NODE_STORAGE_EXTENSION [CMS_NODE]
			-- Extension to the node storage system for node `a_node'.
		do
			if attached node_storage_extensions as tb then
				Result := tb.item (a_node.content_type)
			end
		end

feature {NONE} -- Implementation

	node_storage_extensions: detachable STRING_TABLE [CMS_NODE_STORAGE_EXTENSION [CMS_NODE]]
			-- Table of node storage extensions.

	extended_store (a_node: CMS_NODE)
			-- Store extended data from `a_node'.
		require
			not_has_error: not error_handler.has_error
		do
			if attached node_storage_extension (a_node) as ext then
				ext.store_node (a_node)
			end
		end

	extended_load (a_node: CMS_NODE)
			-- Load extended data into `a_node'.
		require
			not_has_error: not error_handler.has_error
		do
			if attached node_storage_extension (a_node) as ext then
				ext.load_node (a_node)
			end
		end

	extended_delete (a_node: CMS_NODE)
			-- Delete extended data related to node `a_node'.
		require
			not_has_error: not error_handler.has_error
		do
			if attached node_storage_extension (a_node) as ext then
				ext.delete_node (a_node)
			end
		end

feature -- Access		

	nodes_count: NATURAL_64
			-- Count of nodes.
		deferred
		end

	nodes: LIST [CMS_NODE]
			-- List of nodes.
		deferred
		end

	node_revisions (a_node: CMS_NODE): LIST [CMS_NODE]
			-- Revisions of node `a_node'.
		deferred
		end

	trashed_nodes (a_user: detachable CMS_USER): LIST [CMS_NODE]
			-- List of nodes by user `a_user' if set, or any.
		require
			a_user /= Void implies a_user.has_id
		deferred
		end

	recent_nodes (a_lower: INTEGER; a_count: INTEGER): LIST [CMS_NODE]
			-- List of recent `a_count' nodes with an offset of `lower'.
		deferred
		end

	recent_node_changes_before (a_lower: INTEGER; a_count: INTEGER; a_date: DATE_TIME): LIST [CMS_NODE]
			-- List of recent changes, before `a_date', according to `params' settings.
		deferred
		end

	node_by_id (a_id: INTEGER_64): detachable CMS_NODE
			-- Retrieve node by id `a_id', if any.
		require
			a_id > 0
		deferred
		end

	node_by_id_and_revision (a_node_id, a_revision: INTEGER_64): detachable CMS_NODE
			-- Retrieve node by node id `a_node_id' and revision `a_revision', if any.
		require
			has_node_id: a_node_id > 0
			has_revision: a_revision > 0
		deferred
		end

	node_author (a_node: CMS_NODE): detachable CMS_USER
			-- Node's author. if any.
		require
			valid_node: a_node.has_id
		deferred
		end

feature -- Access: outline

	children (a_node: CMS_NODE): detachable LIST [CMS_NODE]
			-- Children of node `a_node'.
			-- note: this is the partial version of the nodes.
		deferred
		end

	available_parents_for_node (a_node: CMS_NODE): LIST [CMS_NODE]
			-- Given the node `a_node', return the list of possible parent nodes id
		deferred
		ensure
			a_node_excluded: across Result as ic all not a_node.same_node (ic.item) end
		end

feature -- Change: Node

	save_node (a_node: CMS_NODE)
			-- Create or update `a_node'.
		do
			if a_node.has_id then
				update_node (a_node)
			else
				new_node (a_node)
			end
		end

	new_node (a_node: CMS_NODE)
			-- Save node `a_node'.
		require
			no_id: not a_node.has_id
			valid_user: attached a_node.author as l_author and then l_author.id > 0
		deferred
		ensure
			has_id: not error_handler.has_error implies a_node.has_id
		end

	update_node (a_node: CMS_NODE)
			-- Update node content `a_node'.
			-- The user `a_id' is an existing or new collaborator.
		require
			has_id: a_node.has_id
			has_author: attached a_node.author as l_author and then l_author.has_id
		deferred
		end

	delete_node (a_node: CMS_NODE)
			-- Delete `a_node'.
		require
				valid_node_id: a_node.has_id
		do
				-- TODO
				-- Check if we need to use a transaction
				-- we delete a node
				-- node_revisions
				-- and extensions (PAGE, BLOG, etc).
			delete_node_base (a_node)
		end

	delete_node_base (a_node: CMS_NODE)
			-- Remove node `a_node'.
		deferred
		end

	trash_node (a_node: CMS_NODE)
			-- Trash `a_node'.
		do
			if a_node.has_id then
				trash_node_by_id (a_node.id)
			end
		end

	restore_node (a_node: CMS_NODE)
			-- Restore `a_node'.
		do
			if a_node.has_id then
				restore_node_by_id (a_node.id)
			end
		end

	trash_node_by_id (a_id: INTEGER_64)
			-- Trash node by id `a_id'.
		require
			valid_node_id: a_id > 0
		deferred
		end

	restore_node_by_id (a_id: INTEGER_64)
			-- Restore node by id `a_id'.
		require
			valid_node_id: a_id > 0
		deferred
		end

feature -- Helpers

	fill_node (a_node: CMS_NODE)
			-- Fill `a_node' with extra information from database.
			-- i.e: specific to each content type data.
		require
			has_id: a_node.has_id
		deferred
		end

end