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 // This file defines utility functions for escaping strings suitable for JSON. 6 7 #ifndef BASE_JSON_STRING_ESCAPE_H_ 8 #define BASE_JSON_STRING_ESCAPE_H_ 9 10 #include <string> 11 12 #include "base/base_export.h" 13 #include "base/strings/string_piece.h" 14 15 namespace base { 16 17 // Appends to |dest| an escaped version of |str|. Valid UTF-8 code units and 18 // characters will pass through from the input to the output. Invalid code 19 // units and characters will be replaced with the U+FFFD replacement character. 20 // This function returns true if no replacement was necessary and false if 21 // there was a lossy replacement. On return, |dest| will contain a valid UTF-8 22 // JSON string. 23 // 24 // Non-printing control characters will be escaped as \uXXXX sequences for 25 // readability. 26 // 27 // If |put_in_quotes| is true, then a leading and trailing double-quote mark 28 // will be appended to |dest| as well. 29 BASE_EXPORT bool EscapeJSONString(StringPiece str, 30 bool put_in_quotes, 31 std::string* dest); 32 33 // Performs a similar function to the UTF-8 StringPiece version above, 34 // converting UTF-16 code units to UTF-8 code units and escaping non-printing 35 // control characters. On return, |dest| will contain a valid UTF-8 JSON string. 36 BASE_EXPORT bool EscapeJSONString(StringPiece16 str, 37 bool put_in_quotes, 38 std::string* dest); 39 40 // Helper functions that wrap the above two functions but return the value 41 // instead of appending. |put_in_quotes| is always true. 42 BASE_EXPORT std::string GetQuotedJSONString(StringPiece str); 43 BASE_EXPORT std::string GetQuotedJSONString(StringPiece16 str); 44 45 // Given an arbitrary byte string |str|, this will escape all non-ASCII bytes 46 // as \uXXXX escape sequences. This function is *NOT* meant to be used with 47 // Unicode strings and does not validate |str| as one. 48 // 49 // CAVEAT CALLER: The output of this function may not be valid JSON, since 50 // JSON requires escape sequences to be valid UTF-16 code units. This output 51 // will be mangled if passed to to the base::JSONReader, since the reader will 52 // interpret it as UTF-16 and convert it to UTF-8. 53 // 54 // The output of this function takes the *appearance* of JSON but is not in 55 // fact valid according to RFC 4627. 56 BASE_EXPORT std::string EscapeBytesAsInvalidJSONString(StringPiece str, 57 bool put_in_quotes); 58 59 } // namespace base 60 61 #endif // BASE_JSON_STRING_ESCAPE_H_ 62