1 files changed, 102 insertions, 0 deletions
diff --git a/grc/core/schema_checker/validator.py b/grc/core/schema_checker/validator.py
new file mode 100644
index 0000000000..ab4d43bc67
--- /dev/null
+++ b/grc/core/schema_checker/validator.py
@@ -0,0 +1,102 @@
+# Copyright 2016 Free Software Foundation, Inc.
+# This file is part of GNU Radio
+#
+# GNU Radio Companion is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 2 of the License, or (at your
+# option) any later version.
+#
+# GNU Radio Companion is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+
+from __future__ import print_function
+
+import six
+
+from .utils import Message, Spec
+
+
+class Validator(object):
+
+    def __init__(self, scheme=None):
+        self._path = []
+        self.scheme = scheme
+        self.messages = []
+        self.passed = False
+
+    def run(self, data):
+        if not self.scheme:
+            return True
+        self._reset()
+        self._path.append('block')
+        self._check(data, self.scheme)
+        self._path.pop()
+        return self.passed
+
+    def _reset(self):
+        del self.messages[:]
+        del self._path[:]
+        self.passed = True
+
+    def _check(self, data, scheme):
+        if not data or not isinstance(data, dict):
+            self._error('Empty data or not a dict')
+            return
+        if isinstance(scheme, dict):
+            self._check_dict(data, scheme)
+        else:
+            self._check_var_key_dict(data, *scheme)
+
+    def _check_var_key_dict(self, data, key_type, value_scheme):
+        for key, value in six.iteritems(data):
+            if not isinstance(key, key_type):
+                self._error('Key type {!r} for {!r} not in valid types'.format(
+                    type(value).__name__, key))
+            if isinstance(value_scheme, Spec):
+                self._check_dict(value, value_scheme)
+            elif not isinstance(value, value_scheme):
+                self._error('Value type {!r} for {!r} not in valid types'.format(
+                    type(value).__name__, key))
+
+    def _check_dict(self, data, scheme):
+        for key, (types_, required, item_scheme) in six.iteritems(scheme):
+            try:
+                value = data[key]
+            except KeyError:
+                if required:
+                    self._error('Missing required entry {!r}'.format(key))
+                continue
+
+            self._check_value(value, types_, item_scheme, label=key)
+
+        for key in set(data).difference(scheme):
+            self._warn('Ignoring extra key {!r}'.format(key))
+
+    def _check_list(self, data, scheme, label):
+        for i, item in enumerate(data):
+            self._path.append('{}[{}]'.format(label, i))
+            self._check(item, scheme)
+            self._path.pop()
+
+    def _check_value(self, value, types_, item_scheme, label):
+        if not isinstance(value, types_):
+            self._error('Value type {!r} for {!r} not in valid types'.format(
+                type(value).__name__, label))
+        if item_scheme:
+            if isinstance(value, list):
+                self._check_list(value, item_scheme, label)
+            elif isinstance(value, dict):
+                self._check(value, item_scheme)
+
+    def _error(self, msg):
+        self.messages.append(Message('.'.join(self._path), 'error', msg))
+        self.passed = False
+
+    def _warn(self, msg):
+        self.messages.append(Message('.'.join(self._path), 'warn', msg))