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[email protected]57319e12012-03-30 22:52:341// Copyright (c) 2012 The Chromium Authors. All rights reserved.
[email protected]1632eb22009-10-01 18:14:122// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// This file defines utility functions for working with html.
6
7#ifndef CHROME_FRAME_HTML_UTILS_H_
8#define CHROME_FRAME_HTML_UTILS_H_
9
10#include <string>
11#include <vector>
12
13#include "base/basictypes.h"
[email protected]19118d52010-07-26 22:13:4214#include "base/gtest_prod_util.h"
[email protected]3f55e872009-10-17 04:48:3715#include "net/http/http_util.h"
[email protected]1632eb22009-10-01 18:14:1216
17// Forward declarations
18class HtmlUtilUnittest;
19
20//
21// Class designed to take a string of HTML and extract from it named
22// attribute values from named tags.
23//
24// Caveat: this class currently doesn't handle multi-word UTF-16 encoded
25// characters. Doesn't handle implies that any data following such a
26// character could possibly be misinterpreted.
27//
28class HTMLScanner {
29 public:
30 typedef std::wstring::const_iterator StrPos;
31
32 // Structure maintaining const_iterators into html_string_.
33 class StringRange {
34 friend class HTMLScanner;
35 public:
36 StringRange();
37 StringRange(StrPos start, StrPos end);
38
39 bool LowerCaseEqualsASCII(const char* other) const;
40 bool Equals(const wchar_t* other) const;
41
42 // Copies the data described by StringRange into destination.
43 std::wstring Copy() const;
44
45 // If this StringRange represents a tag, this method extracts the name of
46 // the tag and sticks it in tag_name.
47 // Returns true if the tag name was successfully extracted.
48 // Returns false if this string doesn't look like a valid tag.
49 bool GetTagName(std::wstring* tag_name) const;
50
51 // From a given string range, uses a string tokenizer to extract the value
52 // of the named attribute if a simple scan finds that the attribute name is
53 // present.
54 //
55 // Returns true if the named attribute can be located and it has a value
56 // which has been placed in attribute_value.
57 //
58 // Note that the attribute value is unquoted here as well, so that
59 // GetTagAttribute(*<foo bar="baz">*, L"bar", *out_value*) will stick
60 // 'bar' in out_value and not '"bar"'.
61 //
62 // Returns false if the named attribute is not present in the tag or if it
63 // did not have a value.
64 //
65 bool GetTagAttribute(const wchar_t* attribute_name,
66 StringRange* attribute_value) const;
67
68 // Unquotes a StringRange by removing a matching pair of either ' or "
69 // characters from the beginning and end of the string if present.
70 // Returns true if string was modified, false otherwise.
71 bool UnQuote();
72 private:
73 StrPos start_;
74 StrPos end_;
75 };
76
77 typedef std::vector<StringRange> StringRangeList;
78
79 // html_string must be a null-terminated string containing the HTML
80 // to be scanned.
81 explicit HTMLScanner(const wchar_t* html_string);
82
83 // Returns the set of ranges denoting HTML tags that match the given name.
84 // If stop_tag_name is given, then as soon as a tag with this name is
85 // encountered this method will return.
86 void GetTagsByName(const wchar_t* name, StringRangeList* tag_list,
87 const wchar_t* stop_tag_name);
88
89 private:
90 friend class HtmlUtilUnittest;
[email protected]19118d52010-07-26 22:13:4291 FRIEND_TEST_ALL_PREFIXES(HtmlUtilUnittest, BasicTest);
[email protected]1632eb22009-10-01 18:14:1292
93 // Given html_string which represents the remaining html range, this method
94 // returns the next tag in tag and advances html_string to one character after
95 // the end of tag. This method is intended to be called repeatedly to extract
96 // all of the tags in sequence.
97 //
98 // Returns true if another tag was found and 'tag' was populated with a valid
99 // range.
100 // Returns false if we have reached the end of the html data.
101 bool NextTag(StringRange* html_string, StringRange* tag);
102
103 // Returns true if c can be found in quotes_, false otherwise
104 bool IsQuote(wchar_t c);
105
106 // Returns true if pos refers to the last character in an HTML comment in a
107 // string described by html_string, false otherwise.
108 // For example with html_string describing <!-- foo> -->, pos must refer to
109 // the last > for this method to return true.
[email protected]9f2c8022010-12-14 20:57:55110 bool IsHTMLCommentClose(const StringRange* html_string, StrPos pos);
111
112 // Returns true if pos refers to the last character in the terminator of the
113 // opening tag of a downlevel-hidden conditional comment in IE as per
114 // http://msdn.microsoft.com/en-us/library/ms537512(VS.85).aspx#syntax
115 // For example with html_string describing <![if booga >wooga]>, pos must
116 // refer to the last > for this method to return true.
117 bool IsIEConditionalCommentClose(const StringRange* html_string, StrPos pos);
[email protected]1632eb22009-10-01 18:14:12118
119 // We store a (CollapsedWhitespace'd) copy of the html data.
120 const std::wstring html_string_;
121
122 // Store the string of quote characters to avoid repeated construction.
123 const std::wstring quotes_;
124
125 DISALLOW_COPY_AND_ASSIGN(HTMLScanner);
126};
127
[email protected]3f55e872009-10-17 04:48:37128namespace http_utils {
129
[email protected]57319e12012-03-30 22:52:34130// Adds "chromeframe/a.b.c.d" to the User-Agent string (a.b.c.d is the version).
131// If the cf tag has already been added to the string, the original string is
132// returned.
[email protected]3f55e872009-10-17 04:48:37133std::string AddChromeFrameToUserAgentValue(const std::string& value);
134
[email protected]57319e12012-03-30 22:52:34135// Removes "chromeframe/a.b.c.d" from the User-Agent string (a.b.c.d is the
136// version). If the cf tag is not present in the string, the original string is
137// returned.
138std::string RemoveChromeFrameFromUserAgentValue(const std::string& value);
139
[email protected]3f55e872009-10-17 04:48:37140// Fetches the user agent from urlmon and adds chrome frame to the
141// comment section.
142// NOTE: The returned string includes the "User-Agent: " header name.
143std::string GetDefaultUserAgentHeaderWithCFTag();
144
[email protected]e67a73f42010-08-31 15:05:02145// Returns the User-Agent header as would be used by Chrome itself.
146const char* GetChromeUserAgent();
147
[email protected]3f55e872009-10-17 04:48:37148// Fetches the default user agent string from urlmon.
149// This value does not include the "User-Agent:" header name.
150std::string GetDefaultUserAgent();
151
152// Returns the Chrome Frame user agent. E.g. "chromeframe/1.0".
153// Note that in unit tests this will be "chromeframe/0.0" due to the version
154// table not being present in the unit test executable.
155const char* GetChromeFrameUserAgent();
156
[email protected]d578d302009-11-19 02:25:42157// Returns true if there is a frame busting header (other than the do-nothing
[email protected]bc2ff5192010-06-01 22:05:45158// "X-Frame-Options: ALLOWALL") in the provided header block. Note that there
159// may be multiple X-Frame-Options values specified; if there is one anywhere in
160// the list with a value other than ALLOWALL, this returns true.
[email protected]d578d302009-11-19 02:25:42161bool HasFrameBustingHeader(const std::string& http_headers);
162
[email protected]f8554292010-09-10 05:06:29163// Returns the header passed in from the headers list.
164std::string GetHttpHeaderFromHeaderList(const std::string& header_name,
165 const std::string& headers);
[email protected]3f55e872009-10-17 04:48:37166} // namespace http_utils
167
[email protected]1632eb22009-10-01 18:14:12168#endif // CHROME_FRAME_HTML_UTILS_H_