Implement declarativeContent API.

chrome/browser/extensions/api/declarative_content/content_condition.cc

+// Copyright (c) 2012 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.
+
+#include "chrome/browser/extensions/api/declarative_content/content_condition.h"
+
+#include "base/bind.h"

[battre, 2012/12/15 11:54:10]

nit: can you check whether all of these are needed

[Jeffrey Yasskin, 2013/01/17 09:22:56]

Done.

+#include "base/logging.h"
+#include "base/stringprintf.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/api/declarative_content/content_constants.h"
+#include "chrome/common/extensions/matcher/url_matcher.h"
+#include "chrome/common/extensions/matcher/url_matcher_factory.h"
+
+namespace keys = extensions::declarative_content_constants;
+
+namespace {
+static extensions::URLMatcherConditionSet::ID g_next_id = 0;
+
+// TODO(jyasskin): improve error messaging to give more meaningful messages
+// to the extension developer.
+// Error messages:
+const char kExpectedDictionary[] = "A condition has to be a dictionary.";
+const char kConditionWithoutInstanceType[] = "A condition had no instanceType";
+const char kExpectedOtherConditionType[] = "Expected a condition of type "
+    "declarativeContent.PageStateMatcher";
+const char kUnknownConditionAttribute[] = "Unknown condition attribute '%s'";
+const char kInvalidTypeOfParamter[] = "Attribute '%s' has an invalid type";
+}  // namespace
+
+namespace extensions {
+
+namespace keys = declarative_content_constants;
+
+RendererContentMatchData::RendererContentMatchData() {}
+RendererContentMatchData::~RendererContentMatchData() {}
+
+//
+// ContentCondition
+//
+
+ContentCondition::ContentCondition(
+    scoped_refptr<URLMatcherConditionSet> url_matcher_conditions,
+    const std::vector<std::string>& css_rules)
+    : url_matcher_conditions_(url_matcher_conditions),
+      css_rules_(css_rules) {
+  CHECK(url_matcher_conditions.get());
+}
+
+ContentCondition::~ContentCondition() {}
+
+bool ContentCondition::IsFulfilled(
+    const RendererContentMatchData& renderer_data) const {
+  // Assume the URL matches or this condition wouldn't get checked.
+
+  // All attributes must be fulfilled for a fulfilled condition.
+  for (std::vector<std::string>::const_iterator i =
+       css_rules_.begin(); i != css_rules_.end(); ++i) {
+    if (!ContainsKey(renderer_data.css_rules, *i))
+      return false;
+  }
+  return true;
+}
+
+// static
+scoped_ptr<ContentCondition> ContentCondition::Create(
+    URLMatcherConditionFactory* url_matcher_condition_factory,
+    const base::Value& condition,
+    std::string* error) {
+  const base::DictionaryValue* condition_dict = NULL;
+  if (!condition.GetAsDictionary(&condition_dict)) {
+    *error = kExpectedDictionary;
+    return scoped_ptr<ContentCondition>(NULL);
+  }
+
+  // Verify that we are dealing with a Condition whose type we understand.
+  std::string instance_type;
+  if (!condition_dict->GetString(keys::kInstanceType, &instance_type)) {
+    *error = kConditionWithoutInstanceType;
+    return scoped_ptr<ContentCondition>(NULL);
+  }
+  if (instance_type != keys::kPageStateMatcherType) {
+    *error = kExpectedOtherConditionType;
+    return scoped_ptr<ContentCondition>(NULL);
+  }
+
+  scoped_refptr<URLMatcherConditionSet> url_matcher_condition_set;
+  std::vector<std::string> css_rules;
+
+  for (base::DictionaryValue::Iterator iter(*condition_dict);
+       iter.HasNext(); iter.Advance()) {
+    const std::string& condition_attribute_name = iter.key();
+    const Value& condition_attribute_value = iter.value();
+    if (condition_attribute_name == keys::kInstanceType) {
+      // Skip this.
+    } else if (condition_attribute_name == keys::kPageUrl) {
+      const base::DictionaryValue* dict = NULL;
+      if (!condition_attribute_value.GetAsDictionary(&dict)) {
+        *error = base::StringPrintf(kInvalidTypeOfParamter,
+                                    condition_attribute_name.c_str());
+      } else {
+        url_matcher_condition_set =
+            URLMatcherFactory::CreateFromURLFilterDictionary(
+                url_matcher_condition_factory, dict, ++g_next_id, error);
+      }
+    } else if (condition_attribute_name == keys::kCss) {
+      const base::ListValue* css_rules_value = NULL;
+      if (!condition_attribute_value.GetAsList(&css_rules_value)) {
+        *error = base::StringPrintf(kInvalidTypeOfParamter,
+                                    condition_attribute_name.c_str());
+      }
+      for (size_t i = 0; i < css_rules_value->GetSize(); ++i) {
+        std::string css_rule;
+        if (!css_rules_value->GetString(i, &css_rule)) {
+          *error = base::StringPrintf(kInvalidTypeOfParamter,
+                                      condition_attribute_name.c_str());
+          break;
+        }
+        css_rules.push_back(css_rule);
+      }
+    } else {
+      *error = base::StringPrintf(kUnknownConditionAttribute,
+                                  condition_attribute_name.c_str());
+    }
+    if (!error->empty())
+      return scoped_ptr<ContentCondition>(NULL);
+  }
+
+  if (!url_matcher_condition_set) {
+    URLMatcherConditionSet::Conditions url_matcher_conditions;
+    url_matcher_conditions.insert(
+        url_matcher_condition_factory->CreateHostPrefixCondition(""));
+    url_matcher_condition_set =
+        new URLMatcherConditionSet(++g_next_id, url_matcher_conditions);
+  }
+  return scoped_ptr<ContentCondition>(
+      new ContentCondition(url_matcher_condition_set, css_rules));
+}
+
+}  // namespace extensions