Make backend write API string-based

Signed-off-by: Nicholas Van Sickle <nvsickle@amazon.com>

Code/Framework/AzCore/AzCore/DOM/Backends/JSON/JsonBackend.h

@@ -10,6 +10,7 @@
 
 #include <AzCore/DOM/Backends/JSON/JsonSerializationUtils.h>
 #include <AzCore/DOM/DomBackend.h>
+#include <AzCore/IO/ByteContainerStream.h>
 
 namespace AZ::Dom
 {
@@ -32,8 +33,9 @@ namespace AZ::Dom
             return Json::VisitSerializedJsonInPlace<ParseFlags>(buffer, visitor);
         }
 
-        Visitor::Result WriteToStream(AZ::IO::GenericStream& stream, WriteCallback callback) override
+        Visitor::Result WriteToBuffer(AZStd::string& buffer, WriteCallback callback)
         {
+            AZ::IO::ByteContainerStream<AZStd::string> stream{ &buffer };
             AZStd::unique_ptr<Visitor> visitor = Json::CreateJsonStreamWriter(stream, WriteFormat);
             return callback(*visitor);
         }

Code/Framework/AzCore/AzCore/DOM/DomBackend.h

@@ -38,7 +38,7 @@ namespace AZ::Dom
         //! A callback that accepts a Visitor, making DOM calls to inform the serializer, and returns an
         //! aggregate error code to indicate whether or not the operation succeeded.
         using WriteCallback = AZStd::function<Visitor::Result(Visitor&)>;
-        //! Attempt to write a value to a stream using a write callback.
-        virtual Visitor::Result WriteToStream(AZ::IO::GenericStream& stream, WriteCallback callback) = 0;
+        //! Attempt to write a value to the specified string using a write callback.
+        virtual Visitor::Result WriteToBuffer(AZStd::string& buffer, WriteCallback callback) = 0;
     };
 } // namespace AZ::Dom

Code/Framework/AzCore/AzCore/DOM/DomUtils.cpp

@@ -21,10 +21,4 @@ namespace AZ::Dom::Utils
     {
         return backend.ReadFromBufferInPlace(string.data(), string.size(), visitor);
     }
-
-    Visitor::Result WriteToString(Backend& backend, AZStd::string& buffer, Backend::WriteCallback writeCallback)
-    {
-        AZ::IO::ByteContainerStream<AZStd::string> stream{ &buffer };
-        return backend.WriteToStream(stream, writeCallback);
-    }
 }

Code/Framework/AzCore/AzCore/DOM/DomUtils.h

@@ -14,6 +14,4 @@ namespace AZ::Dom::Utils
 {
     Visitor::Result ReadFromString(Backend& backend, AZStd::string_view string, AZ::Dom::Lifetime lifetime, Visitor& visitor);
     Visitor::Result ReadFromStringInPlace(Backend& backend, AZStd::string& string, Visitor& visitor);
-
-    Visitor::Result WriteToString(Backend& backend, AZStd::string& buffer, Backend::WriteCallback writeCallback);
 } // namespace AZ::Dom::Utils

Code/Framework/AzCore/Tests/DOM/DomJsonTests.cpp

@@ -71,7 +71,7 @@ namespace AZ::Dom::Tests
             {
                 AZStd::string serializedDocument;
                 JsonBackend backend;
-                auto result = Dom::Utils::WriteToString(backend, serializedDocument, visitDocumentFn);
+                auto result = backend.WriteToBuffer(serializedDocument, visitDocumentFn);
                 EXPECT_TRUE(result.IsSuccess());
                 EXPECT_EQ(canonicalSerializedDocument, serializedDocument);
             }
@@ -92,8 +92,8 @@ namespace AZ::Dom::Tests
             {
                 AZStd::string serializedDocument;
                 JsonBackend backend;
-                auto result = Dom::Utils::WriteToString(
-                    backend, serializedDocument,
+                auto result = backend.WriteToBuffer(
+                    serializedDocument,
                     [&backend, &canonicalSerializedDocument](AZ::Dom::Visitor& visitor)
                     {
                         return Dom::Utils::ReadFromString(backend, canonicalSerializedDocument, Lifetime::Temporary, visitor);