properties: fix json validity on Windows

Clement Champetier · Clement Champetier · commit 184a1835b865 · 2015-12-04T17:15:51.000+01:00
* Added JsonStreamWriter::escapeJsonString to escape strings accordingly to the JSON standard.
diff --git a/src/AvTranscoder/properties/JsonWriter.cpp b/src/AvTranscoder/properties/JsonWriter.cpp
@@ -1,8 +1,23 @@
 #include "JsonWriter.hpp"
 
+#include <string>
+#include <sstream>
+
 namespace avtranscoder {
 namespace json {
 
+std::string JsonStreamWriter::escapeJsonString(const std::string& input)
+{
+	std::ostringstream ss;
+	for (std::string::const_iterator iter = input.begin(); iter != input.end(); iter++) {
+		switch (*iter) {
+			case '\\': ss << "\\\\"; break;
+			default: ss << *iter; break;
+		}
+	}
+	return ss.str();
+}
+
 template <>
 JsonStreamWriter& JsonStreamWriter::operator<<(bool value)
 {
diff --git a/src/AvTranscoder/properties/JsonWriter.hpp b/src/AvTranscoder/properties/JsonWriter.hpp
@@ -52,6 +52,9 @@ class AvExport JsonStreamWriter
 	}
 
 	virtual std::ostream& finish() = 0;
+
+	// Escape strings accordingly to the JSON standard
+	std::string escapeJsonString(const std::string& input);
 };
 
 // Write a boolean to the stream.
@@ -76,6 +79,15 @@ class AvExport JsonObjectStreamWriter : public JsonStreamWriter
 		return *this;
 	}
 
+	template<>
+	JsonObjectStreamWriter& operator<<(const std::pair<const char *, const char*> pair)
+	{
+		std::string first(pair.first);
+		std::string second(pair.second);
+		addSep() << escapeJsonString(first).c_str() << ':' << escapeJsonString(second).c_str();
+		return *this;
+	}
+
 protected:
 	virtual std::ostream& finish() { return stream << '}'; }
 };
diff --git a/test/pyTest/testProperties.py b/test/pyTest/testProperties.py
@@ -138,7 +138,5 @@ def testCheckFilePropertiesAsJson():
     inputFile = av.InputFile( inputFileName )
 
     import json
-    # throw exception if it is not a valid JSON
+    # json.loads method throws a ValueError if it is not a valid JSON.
     json.loads(inputFile.getProperties().allPropertiesAsJson())
-
-
