tools/json_schema_compiler/schema_loader.py

   1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 import os
   6 import re
   7 import sys
   8
   9 import idl_schema
  10 import json_schema
  11 from model import Model, UnixName
  12
  13 class SchemaLoader(object):
  14   '''Resolves a type name into the namespace the type belongs to.
  15
  16   Properties:
  17   - |display_path| path to the directory with the API header files, intended for
  18   use with the Model.
  19   - |real_path| path to the directory with the API header files, used for file
  20   access.
  21   '''
  22   def __init__(self, display_path, real_path):
  23     self._display_path = display_path
  24     self._real_path = real_path
  25
  26   def ResolveType(self, full_name, default_namespace):
  27     name_parts = full_name.rsplit('.', 1)
  28     if len(name_parts) == 1:
  29       if full_name not in default_namespace.types:
  30         return None
  31       return default_namespace
  32     namespace_name, type_name = name_parts
  33     real_name = None
  34     # Try to find the file defining the namespace. Eg. for
  35     # nameSpace.sub_name_space.Type' the following heuristics looks for:
  36     # 1. name_space_sub_name_space.json,
  37     # 2. name_space_sub_name_space.idl.
  38     for ext in ['json', 'idl']:
  39       basename = UnixName(namespace_name)
  40       filename = '%s.%s' % (basename, ext)
  41       filepath = os.path.join(self._real_path, filename);
  42       if os.path.exists(filepath):
  43         real_name = filename
  44         break
  45     if real_name is None:
  46       return None
  47     namespace = Model().AddNamespace(
  48         self.LoadSchema(real_name)[0],
  49         os.path.join(self._display_path, real_name))
  50     if type_name not in namespace.types:
  51       return None
  52     return namespace
  53
  54   def LoadSchema(self, schema):
  55     '''Load a schema definition. The schema parameter must be a file name
  56     without any path component - the file is loaded from the path defined by
  57     the real_path argument passed to the constructor.'''
  58     schema_filename, schema_extension = os.path.splitext(schema)
  59
  60     schema_path = os.path.join(self._real_path, schema);
  61     if schema_extension == '.json':
  62       api_defs = json_schema.Load(schema_path)
  63     elif schema_extension == '.idl':
  64       api_defs = idl_schema.Load(schema_path)
  65     else:
  66       sys.exit('Did not recognize file extension %s for schema %s' %
  67                (schema_extension, schema))
  68
  69     return api_defs