Improve error message display for Schema::Validate()

components/policy/core/common/schema.h

 // Copyright 2013 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.
 
 #ifndef COMPONENTS_POLICY_CORE_COMMON_SCHEMA_H_
 #define COMPONENTS_POLICY_CORE_COMMON_SCHEMA_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 61 matching lines @@
   static Schema Parse(const std::string& schema, std::string* error);
 
   // Returns true if this Schema is valid. Schemas returned by the methods below
   // may be invalid, and in those cases the other methods must not be used.
   bool valid() const { return node_ != NULL; }
 
   base::Value::Type type() const;
 
   // Validate |value| against current schema, |strategy| is the strategy to
   // handle unknown properties or invalid values. Allowed errors will be
-  // ignored. If |value| don't conform the schema, false will be returned and
-  // |error| will contain the detailed reason.
+  // ignored. |error_path| and |error| will contain the last error location and
+  // detailed message if |value| doesn't strictly conform to the schema. If
+  // |value| doesn't conform to the schema even within the allowance of
+  // |strategy|, false will be returned and |error_path| and |error| will
+  // contain the corresponding error that caused the failure. |error_path| can
+  // be NULL and in that case no error path will be returned.
   bool Validate(const base::Value& value,
                 SchemaOnErrorStrategy strategy,
+                std::string* error_path,
                 std::string* error) const;
 
-  // Validate |value| against current schema, |strategy| is the strategy to
-  // handle unknown properties or invalid values. Allowed errors will be
-  // dropped in place. If |value| don't conform the schema, false will be
-  // returned and |error| will contain the detailed message.
+  // Same as Validate() but drop values with errors instead of ignoring them.
   bool Normalize(base::Value* value,
                  SchemaOnErrorStrategy strategy,
+                 std::string* error_path,
                  std::string* error) const;
 
   // Used to iterate over the known properties of TYPE_DICTIONARY schemas.
   class POLICY_EXPORT Iterator {
    public:
     Iterator(const scoped_refptr<const InternalStorage>& storage,
              const internal::PropertiesNode* node);
     Iterator(const Iterator& iterator);
     ~Iterator();
 
@@ skipping 41 matching lines @@
   // otherwise invalid memory will be read. A CHECK is currently enforcing this.
   Schema GetItems() const;
 
  private:
   // Builds a schema pointing to the inner structure of |storage|,
   // rooted at |node|.
   Schema(const scoped_refptr<const InternalStorage>& storage,
          const internal::SchemaNode* node);
 
   bool ValidateIntegerRestriction(int index, int value) const;
-  bool ValidateStringRestriction(int index, const char *str) const;
+  bool ValidateStringRestriction(int index, const char* str) const;
 
   scoped_refptr<const InternalStorage> storage_;
   const internal::SchemaNode* node_;
 };
 
 }  // namespace policy
 
 #endif  // COMPONENTS_POLICY_CORE_COMMON_SCHEMA_H_