Add read-only access to POST data for webRequest's onBeforeRequest

chrome/browser/extensions/api/web_request/upload_data_presenter.h

+// 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_API_WEB_REQUEST_UPLOAD_DATA_PRESENTER_H_
+#define CHROME_BROWSER_EXTENSIONS_API_WEB_REQUEST_UPLOAD_DATA_PRESENTER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace base {
+class DictionaryValue;
+class ListValue;
+class Value;
+}
+
+namespace extensions {
+class FormDataParser;
+}
+
+namespace net {
+class URLRequest;
+class UploadElement;
+}
+
+namespace extensions {
+
+FORWARD_DECLARE_TEST(WebRequestUploadDataPresenterTest, RawData);
+
+// UploadDataPresenter is an interface for objects capable to consume a series
+// of UploadElement and represent this data as a base:Value.
+//
+// Workflow for objects implementing this interface:
+// 1. Call object->FeedNext(element) for each element from the request's body.
+// 2. Check if object->Succeeded().
+// 3. If that check passed then retrieve object->Result().
+class UploadDataPresenter {
+ public:
+  virtual ~UploadDataPresenter();
+  virtual void FeedNext(const net::UploadElement& element) = 0;
+  virtual bool Succeeded() = 0;
+  virtual scoped_ptr<base::Value> Result() = 0;
+
+ protected:
+  UploadDataPresenter() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(UploadDataPresenter);
+};
+
+// This class checks that chunked transfer encoding (defined in RFC 2616)
+// is not used. If it is, an error string is generated.
+class ChunkedErrorPresenter : public UploadDataPresenter {
+ public:
+  explicit ChunkedErrorPresenter(const net::URLRequest* request);
+  virtual ~ChunkedErrorPresenter();
+
+  // Tests the headers of |request| for transfer encoding.
+  static bool IsTransferEncodingChunked(const net::URLRequest* request);
+
+  // Implementation of UploadDataPresenter.
+  virtual void FeedNext(const net::UploadElement& element) OVERRIDE;
+  virtual bool Succeeded() OVERRIDE;
+  virtual scoped_ptr<base::Value> Result() OVERRIDE;
+
+ private:
+  bool chunks_found_;
+};
+
+// This class passes all the bytes from elements of TYPE_BYTES as a BinaryValue
+// for each such element. Elements of TYPE_FILE are presented as StringValue
+// containing the path for that file. The presence of TYPE_CHUNK elements causes
+// a failure.
+class RawDataPresenter : public UploadDataPresenter {
+ public:
+  RawDataPresenter();
+  virtual ~RawDataPresenter();
+
+  // Implementation of UploadDataPresenter.
+  virtual void FeedNext(const net::UploadElement& element) OVERRIDE;
+  virtual bool Succeeded() OVERRIDE;
+  virtual scoped_ptr<base::Value> Result() OVERRIDE;
+
+  // Appends a dictionary {'key': 'value'} to |list|.
+  // This is a helper function and has nothing to do with RawDataPresenter
+  // directly. However, it is used by FeedNext* methods and also unit-tests
+  // depending on RawDataPresenter. It is here to avoid code duplication.
+  static void AppendResultWithKey(
+      base::ListValue* list, const char* key, base::Value* value);
+
+ private:
+  // Clears resources and the success flag.
+  void Abort();
+
+  void FeedNextBytes(const char* bytes, size_t size);
+  void FeedNextFile(const std::string& filename);
+  FRIEND_TEST_ALL_PREFIXES(WebRequestUploadDataPresenterTest, RawData);
+
+  bool success_;
+  scoped_ptr<base::ListValue> list_;
+};
+
+// This class inspects the contents of elements of TYPE_BYTES. It uses the
+// parser classes inheriting from FormDataParser to parse the concatenated
+// content of such elements. If the parsing is successfull, the parsed form is
+// returned as a DictionaryValue. For example, a form consisting of
+// <input name="check" type="checkbox" value="A" checked />
+// <input name="check" type="checkbox" value="B" checked />
+// <input name="text" type="text" value="abc" />
+// would be represented as {"check": ["A", "B"], "text": ["abc"]} (although as a
+// DictionaryValue, not as a JSON string).
+class ParsedDataPresenter : public UploadDataPresenter {
+ public:
+  explicit ParsedDataPresenter(const net::URLRequest* request);
+  virtual ~ParsedDataPresenter();
+
+  // Implementation of UploadDataPresenter.
+  virtual void FeedNext(const net::UploadElement& element) OVERRIDE;
+  virtual bool Succeeded() OVERRIDE;
+  virtual scoped_ptr<base::Value> Result() OVERRIDE;
+
+ private:
+  // Clears resources and the success flag.
+  void Abort();
+  scoped_ptr<FormDataParser> parser_;
+  bool success_;
+  scoped_ptr<base::DictionaryValue> dictionary_;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_WEB_REQUEST_UPLOAD_DATA_PRESENTER_H_