Automatically generate externs.js for a format (idl, json) supported by tools/json_schema_compiler.

tools/json_schema_compiler/externs_js_generator.py

Index: tools/json_schema_compiler/externs_js_generator.py
diff --git a/tools/json_schema_compiler/externs_js_generator.py b/tools/json_schema_compiler/externs_js_generator.py
new file mode 100644
index 0000000000000000000000000000000000000000..fb3e056c53ee3bcf9372679d31512fe51a1f3669
--- /dev/null
+++ b/tools/json_schema_compiler/externs_js_generator.py
@@ -0,0 +1,60 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""
+Generates an externs.js file for Chrome extension APIs.
+"""
+
+from code import Code
+from model import CamelName, Function, PropertyType
+from schema_util import StripNamespace
+
+import os
+from datetime import datetime
+
+LICENSE = (
+"""// Copyright %s The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.""" %
+    datetime.now().year)
+
+PREAMBLE = (
+"""// Auto generated externs.js; do not edit.
+""")
+
+class ExternsJsGenerator(object):
+  def Generate(self, namespace):
+    self.api_namespace_ = 'chrome.%s' % CamelName(namespace.unix_name)
+
+    c = Code()
+    c.Append(LICENSE)
+
+    c.Append()
+
+    c.Append('/**')
+    c.Append(' * @const')
+    c.Append(' */')
+    c.Append('%s = {};' % self.api_namespace_)
+
+    # TODO(dtseng): Support namespace.functions, namespace.events.
+    for value in namespace.types.values():
+      c.Append('/**')
+      if value.description:
+        c.Append(' * %s' % value.description)
+      if value.property_type.name == 'enum':
+        c.Append(' * @enum {string}')
+        c.Append(' */')
+        c.Append('%s.%s = {' % (self.api_namespace_, value.name))
+        entries = []
+        for enum_value in value.enum_values:
+          entries.append('    %s: \'%s\'' % (enum_value.name, enum_value.name))
+        c.Append(',\n'.join(entries))
+        c.Append('};')
+      elif value.property_type.name == 'object':
+        # TODO(dtseng): Implement fully.
+        c.Append(' * @constructor')
+        c.Append(' */')
+        c.Append('%s.%s = function() {};' % (self.api_namespace_, value.name))
+      else:
+        raise Exception('Unknown property type: %s' % value.property_type.name)
+    return c