schema: Attempt to ensure chunk commands are ordered properly

This isn't tested yet fully because the browser example app has started
ignoring all of the data.

Change-Id: I91ca6b519f6feacb9e6e5269c577858d285009aa

1 files changed, 35 insertions, 21 deletions

diff --git a/schema/parse.py b/schema/parse.py
index 1ee1b367..8a79e986 100644
--- a/schema/parse.py
+++ b/schema/parse.py
@@ -28,6 +28,7 @@ The current version of the Baserock Definitions format is defined at:
 
 
 import rdflib
+import rdflib.collection
 import yaml
 
 import os
@@ -67,8 +68,6 @@ def get_name_from_morph_file(path):
     return contents['name']
 
 
-# FIXME: can you use assignment instead of Resource.set ?
-
 class DefinitionsNamespace(rdflib.Namespace):
     '''Helpers to construct URIs for Baserock entities.
 
@@ -107,6 +106,21 @@ class DefinitionsNamespace(rdflib.Namespace):
         return cluster_uriref + '/' + label
 
 
+def ordered(graph, value_list, node=None):
+    '''Create an ordered RDF collection from a list of values.
+
+    To define an ordered list in RDF, you need an identifier for the list
+    itself. By default this function will create a 'blank node', which will end
+    up with a random unique URI when serialised. To make serialised data more
+    readable you can create your own rdflib.URIRef term to identify the list.
+
+    '''
+    node = node or rdflib.BNode()
+    collection = rdflib.collection.Collection(
+        graph, node, [rdflib.Literal(v) for v in value_list])
+    return node
+
+
 def load_all_morphologies(path='.'):
     '''Load Baserock Definitions serialisation format V5 as an RDFLib 'graph'.
 
@@ -117,6 +131,7 @@ def load_all_morphologies(path='.'):
     toplevel_path = path
     graph = rdflib.Graph()
 
+
     def load_morph(toplevel_path, filename):
         try:
             contents = parse_morph_file(filename)
@@ -133,34 +148,33 @@ def load_all_morphologies(path='.'):
             chunk_uriref = ns.chunk(contents['name'])
             entity = chunk = rdflib.resource.Resource(graph, chunk_uriref)
 
-            # FIXME: order is lost here !!!!!
             if 'pre-configure-commands' in contents:
-                chunk.add(BASEROCK.preConfigureCommands,
-                          rdflib.Literal(contents['pre-configure-commands']))
+                chunk.set(BASEROCK.preConfigureCommands,
+                          ordered(graph, contents['pre-configure-commands']))
             if 'configure-commands' in contents:
-                chunk.add(BASEROCK.configureCommands,
-                          rdflib.Literal(contents['configure-commands']))
+                chunk.set(BASEROCK.configureCommands,
+                          ordered(graph, contents['configure-commands']))
             if 'post-configure-commands' in contents:
-                chunk.add(BASEROCK.postConfigureCommands,
-                          rdflib.Literal(contents['post-configure-commands']))
+                chunk.set(BASEROCK.postConfigureCommands,
+                          ordered(graph, contents['post-configure-commands']))
             if 'pre-build-commands' in contents:
-                chunk.add(BASEROCK.preBuildCommands,
-                          rdflib.Literal(contents['pre-build-commands']))
+                chunk.set(BASEROCK.preBuildCommands,
+                          ordered(graph, contents['pre-build-commands']))
             if 'build-commands' in contents:
-                chunk.add(BASEROCK.buildCommands,
-                          rdflib.Literal(contents['build-commands']))
+                chunk.set(BASEROCK.buildCommands,
+                          ordered(graph, contents['build-commands']))
             if 'post-build-commands' in contents:
-                chunk.add(BASEROCK.postBuildCommands,
-                          rdflib.Literal(contents['post-build-commands']))
+                chunk.set(BASEROCK.postBuildCommands,
+                          ordered(graph, contents['post-build-commands']))
             if 'pre-install-commands' in contents:
-                chunk.add(BASEROCK.preInstallCommands,
-                          rdflib.Literal(contents['pre-install-commands']))
+                chunk.set(BASEROCK.preInstallCommands,
+                          ordered(graph, contents['pre-install-commands']))
             if 'install-commands' in contents:
-                chunk.add(BASEROCK.installCommands,
-                          rdflib.Literal(contents['install-commands']))
+                chunk.set(BASEROCK.installCommands,
+                          ordered(graph, contents['install-commands']))
             if 'post-install-commands' in contents:
-                chunk.add(BASEROCK.postInstallCommands,
-                          rdflib.Literal(contents['post-install-commands']))
+                chunk.set(BASEROCK.postInstallCommands,
+                          ordered(graph, contents['post-install-commands']))
 
         elif contents['kind'] == 'stratum':
             stratum_uriref = ns.stratum(contents['name'])