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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef BASE_JSON_JSON_WRITER_H_
6 #define BASE_JSON_JSON_WRITER_H_
7 #pragma once
8 
9 #include <string>
10 
11 #include "base/base_api.h"
12 #include "base/basictypes.h"
13 
14 class Value;
15 
16 namespace base {
17 
18 class BASE_API JSONWriter {
19  public:
20   // Given a root node, generates a JSON string and puts it into |json|.
21   // If |pretty_print| is true, return a slightly nicer formated json string
22   // (pads with whitespace to help readability).  If |pretty_print| is false,
23   // we try to generate as compact a string as possible.
24   // TODO(tc): Should we generate json if it would be invalid json (e.g.,
25   // |node| is not a DictionaryValue/ListValue or if there are inf/-inf float
26   // values)?
27   static void Write(const Value* const node, bool pretty_print,
28                     std::string* json);
29 
30   // Same as above, but has an option to not escape the string, preserving its
31   // UTF8 characters. It is useful if you can pass resulting string to the
32   // JSON parser in binary form (as UTF8).
33   static void WriteWithOptionalEscape(const Value* const node,
34                                       bool pretty_print,
35                                       bool escape,
36                                       std::string* json);
37 
38   // A static, constant JSON string representing an empty array.  Useful
39   // for empty JSON argument passing.
40   static const char* kEmptyArray;
41 
42  private:
43   JSONWriter(bool pretty_print, std::string* json);
44 
45   // Called recursively to build the JSON string.  Whe completed, value is
46   // json_string_ will contain the JSON.
47   void BuildJSONString(const Value* const node, int depth, bool escape);
48 
49   // Appends a quoted, escaped, version of (UTF-8) str to json_string_.
50   void AppendQuotedString(const std::string& str);
51 
52   // Adds space to json_string_ for the indent level.
53   void IndentLine(int depth);
54 
55   // Where we write JSON data as we generate it.
56   std::string* json_string_;
57 
58   bool pretty_print_;
59 
60   DISALLOW_COPY_AND_ASSIGN(JSONWriter);
61 };
62 
63 }  // namespace base
64 
65 #endif  // BASE_JSON_JSON_WRITER_H_
66