1 // Copyright (c) 2012 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 8 #include <stddef.h> 9 10 #include <string> 11 12 #include "base/base_export.h" 13 #include "base/macros.h" 14 15 namespace base { 16 17 class Value; 18 19 class BASE_EXPORT JSONWriter { 20 public: 21 enum Options { 22 // This option instructs the writer that if a Binary value is encountered, 23 // the value (and key if within a dictionary) will be omitted from the 24 // output, and success will be returned. Otherwise, if a binary value is 25 // encountered, failure will be returned. 26 OPTIONS_OMIT_BINARY_VALUES = 1 << 0, 27 28 // This option instructs the writer to write doubles that have no fractional 29 // part as a normal integer (i.e., without using exponential notation 30 // or appending a '.0') as long as the value is within the range of a 31 // 64-bit int. 32 OPTIONS_OMIT_DOUBLE_TYPE_PRESERVATION = 1 << 1, 33 34 // Return a slightly nicer formatted json string (pads with whitespace to 35 // help with readability). 36 OPTIONS_PRETTY_PRINT = 1 << 2, 37 }; 38 39 // Given a root node, generates a JSON string and puts it into |json|. 40 // The output string is overwritten and not appended. 41 // 42 // TODO(tc): Should we generate json if it would be invalid json (e.g., 43 // |node| is not a DictionaryValue/ListValue or if there are inf/-inf float 44 // values)? Return true on success and false on failure. 45 static bool Write(const Value& node, std::string* json); 46 47 // Same as above but with |options| which is a bunch of JSONWriter::Options 48 // bitwise ORed together. Return true on success and false on failure. 49 static bool WriteWithOptions(const Value& node, 50 int options, 51 std::string* json); 52 53 private: 54 JSONWriter(int options, std::string* json); 55 56 // Called recursively to build the JSON string. When completed, 57 // |json_string_| will contain the JSON. 58 bool BuildJSONString(const Value& node, size_t depth); 59 60 // Adds space to json_string_ for the indent level. 61 void IndentLine(size_t depth); 62 63 bool omit_binary_values_; 64 bool omit_double_type_preservation_; 65 bool pretty_print_; 66 67 // Where we write JSON data as we generate it. 68 std::string* json_string_; 69 70 DISALLOW_COPY_AND_ASSIGN(JSONWriter); 71 }; 72 73 } // namespace base 74 75 #endif // BASE_JSON_JSON_WRITER_H_ 76
