1/*
2 * libjingle
3 * Copyright 2010, Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 *  1. Redistributions of source code must retain the above copyright notice,
9 *     this list of conditions and the following disclaimer.
10 *  2. Redistributions in binary form must reproduce the above copyright notice,
11 *     this list of conditions and the following disclaimer in the documentation
12 *     and/or other materials provided with the distribution.
13 *  3. The name of the author may not be used to endorse or promote products
14 *     derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#ifndef TALK_P2P_BASE_PARSING_H_
29#define TALK_P2P_BASE_PARSING_H_
30
31#include <string>
32#include <vector>
33#include "webrtc/libjingle/xmllite/xmlelement.h"  // Needed to delete ParseError.extra.
34#include "webrtc/base/basictypes.h"
35#include "webrtc/base/stringencode.h"
36
37namespace cricket {
38
39typedef std::vector<buzz::XmlElement*> XmlElements;
40
41// We decided "bool Parse(in, out*, error*)" is generally the best
42// parse signature.  "out Parse(in)" doesn't allow for errors.
43// "error* Parse(in, out*)" doesn't allow flexible memory management.
44
45// The error type for parsing.
46struct ParseError {
47 public:
48  // explains the error
49  std::string text;
50  // provide details about what wasn't parsable
51  const buzz::XmlElement* extra;
52
53  ParseError() : extra(NULL) {}
54
55  ~ParseError() {
56    delete extra;
57  }
58
59  void SetText(const std::string& text) {
60    this->text = text;
61  }
62};
63
64// The error type for writing.
65struct WriteError {
66  std::string text;
67
68  void SetText(const std::string& text) {
69    this->text = text;
70  }
71};
72
73// Convenience method for returning a message when parsing fails.
74bool BadParse(const std::string& text, ParseError* err);
75
76// Convenience method for returning a message when writing fails.
77bool BadWrite(const std::string& text, WriteError* error);
78
79// helper XML functions
80std::string GetXmlAttr(const buzz::XmlElement* elem,
81                       const buzz::QName& name,
82                       const std::string& def);
83std::string GetXmlAttr(const buzz::XmlElement* elem,
84                       const buzz::QName& name,
85                       const char* def);
86// Return true if the value is "true" or "1".
87bool GetXmlAttr(const buzz::XmlElement* elem,
88                const buzz::QName& name, bool def);
89int GetXmlAttr(const buzz::XmlElement* elem,
90               const buzz::QName& name, int def);
91
92template <class T>
93bool GetXmlAttr(const buzz::XmlElement* elem,
94                const buzz::QName& name,
95                T* val_out) {
96  if (!elem->HasAttr(name)) {
97    return false;
98  }
99  std::string unparsed = elem->Attr(name);
100  return rtc::FromString(unparsed, val_out);
101}
102
103template <class T>
104bool GetXmlAttr(const buzz::XmlElement* elem,
105                const buzz::QName& name,
106                const T& def,
107                T* val_out) {
108  if (!elem->HasAttr(name)) {
109    *val_out = def;
110    return true;
111  }
112  return GetXmlAttr(elem, name, val_out);
113}
114
115template <class T>
116bool AddXmlAttr(buzz::XmlElement* elem,
117                const buzz::QName& name, const T& val) {
118  std::string buf;
119  if (!rtc::ToString(val, &buf)) {
120    return false;
121  }
122  elem->AddAttr(name, buf);
123  return true;
124}
125
126template <class T>
127bool SetXmlBody(buzz::XmlElement* elem, const T& val) {
128  std::string buf;
129  if (!rtc::ToString(val, &buf)) {
130    return false;
131  }
132  elem->SetBodyText(buf);
133  return true;
134}
135
136const buzz::XmlElement* GetXmlChild(const buzz::XmlElement* parent,
137                                    const std::string& name);
138
139bool RequireXmlChild(const buzz::XmlElement* parent,
140                     const std::string& name,
141                     const buzz::XmlElement** child,
142                     ParseError* error);
143bool RequireXmlAttr(const buzz::XmlElement* elem,
144                    const buzz::QName& name,
145                    std::string* value,
146                    ParseError* error);
147void AddXmlAttrIfNonEmpty(buzz::XmlElement* elem,
148                          const buzz::QName name,
149                          const std::string& value);
150void AddXmlChildren(buzz::XmlElement* parent,
151                    const std::vector<buzz::XmlElement*>& children);
152void CopyXmlChildren(const buzz::XmlElement* source, buzz::XmlElement* dest);
153std::vector<buzz::XmlElement*> CopyOfXmlChildren(const buzz::XmlElement* elem);
154
155}  // namespace cricket
156
157#endif  // TALK_P2P_BASE_PARSING_H_
158