Make SchemaLoader independent of current working directory.

tools/json_schema_compiler/schema_loader.py

Index: tools/json_schema_compiler/schema_loader.py
diff --git a/tools/json_schema_compiler/schema_loader.py b/tools/json_schema_compiler/schema_loader.py
index c434dc167462a26a6e913a28e50d8b9bb79a4126..f74df8956e316aeccfcdb0bdef4d9f9a81e069bf 100644
--- a/tools/json_schema_compiler/schema_loader.py
+++ b/tools/json_schema_compiler/schema_loader.py
@@ -12,7 +12,8 @@ from model import Model
 class SchemaLoader(object):
   '''Resolves a type name into the namespace the type belongs to.
   '''
-  def __init__(self, api_path):
+  def __init__(self, root, api_path):
+    self._root = root
     self._api_path = api_path
 
   def ResolveType(self, full_name, default_namespace):
@@ -25,7 +26,8 @@ class SchemaLoader(object):
     real_name = None
     for ext in ['json', 'idl']:
       filename = '%s.%s' % (namespace_name, ext)
-      if os.path.exists(filename):
+      filepath = os.path.join(self._root, self._api_path, filename);
+      if os.path.exists(filepath):
         real_name = filename
         break
     if real_name is None:
@@ -37,12 +39,16 @@ class SchemaLoader(object):
     return namespace
 
   def LoadSchema(self, schema):
+    '''Load a schema definition. The schema parameter must be a file name
+       without any path component - the file is loaded from the path defined by
+       the root and api_path arguments passed to the constructor.'''
     schema_filename, schema_extension = os.path.splitext(schema)
 
+    schema_path = os.path.join(self._root, self._api_path, schema);

[not at google - send to devlin, 2013/09/19 15:43:34]

can the caller just make sure that the root is properly prepended to api_path?

[msimonides, 2013/09/20 11:32:01]

This would be a problem with line 35-36: Model().AddNamespace(). If I modify the
_api_path as you suggest, the generated header files will have incorrect
#include paths.

[not at google - send to devlin, 2013/09/20 20:37:57]

Ah. So there's a long-standing cleanup where we don't actually need the api path
to be passed into those Namespaces, they should be passed into the code
generators.

But unless you're keen to fix that now (which would be great, but I would
understand if not), I'd still rather pass in 2 separate paths rather than 1 path
and a root.

     if schema_extension == '.json':
-      api_defs = json_schema.Load(schema)
+      api_defs = json_schema.Load(schema_path)
     elif schema_extension == '.idl':
-      api_defs = idl_schema.Load(schema)
+      api_defs = idl_schema.Load(schema_path)
     else:
       sys.exit('Did not recognize file extension %s for schema %s' %
                (schema_extension, schema))