private void WriteTypeDiscriminatorConverterBody(SourceWriter w, string baseType, JensonPropertyInfo p, string discrFun)
{
w.Line($"public override {baseType} Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)");
w.Line("{");
w.Indent();
w.Line("var discrReader = reader;");
w.Line($"var discriminatorName = Encoding.UTF8.GetBytes(\"{p.Name}\");");
w.Line();
w.Line("if (discrReader.TokenType != JsonTokenType.StartObject) throw new JsonException(\"Expected start of object.\");");
w.Line();
w.Line("while (discrReader.Read())");
w.Line("{");
w.Indent();
w.Line("if (discrReader.ValueTextEquals(discriminatorName))");
w.Line("{");
w.Indent();
w.Line("if (!discrReader.Read()) throw new JsonException();");
// TODO proper deserialization of value
w.Line($"var value = JsonSerializer.Deserialize<{p.TypeName}>(ref discrReader);");
w.Line($"var realType = {baseType}.{discrFun}(value);");
w.Line($"return ({baseType}) JsonSerializer.Deserialize(ref reader, realType, options);");
w.Dedent();
w.Line("}");
w.Line();
w.Line("discrReader.Skip();");
w.Dedent();
w.Line("}");
w.Line();
w.Line("throw new JsonException(\"Missing type discriminator.\");");
w.Dedent();
w.Line("}");
w.Line();
w.Line($"public override void Write(Utf8JsonWriter writer, {baseType} value, JsonSerializerOptions options)");
w.Line("{");
w.Indent();
w.Line("throw new NotImplementedException(\"A converter for subclasses must always be used for writing.\");");
w.Dedent();
w.Line("}");
}
private string GenerateReadArray(JensonPropertyInfo p)
{
var w = new SourceWriter();
w.Line("if (reader.TokenType != JsonTokenType.StartArray) throw new JsonException();");
w.Line();
w.Line($"{p.Name} = JsonSerializer.Deserialize<{p.TypeName}>(ref reader);");
return(w.ToString());
w.Line("var restore = reader;");
w.Line("var length = 0;");
w.Line();
w.Line("while (reader.Read() && reader.TokenType != JsonTokenType.EndArray)");
w.Line("{");
w.Indent();
w.Line("if (reader.TokenType != JsonTokenType.Comment) length++;");
w.Line("reader.Skip();");
w.Dedent();
w.Line("}");
w.Line();
w.Line("reader = restore;");
w.Line($"{p.Name} = new {p.TypeName.Substring(0, p.TypeName.Length - 2)}[length];");
var itemType = p.ArrayItemType;
if (itemType.EndsWith("[]"))
{
throw new NotImplementedException("Nested arrays are not implemented.");
}
//var attribList = new List<OpAttribute>();
//while (reader.Read())
//{
// if (reader.TokenType == JsonTokenType.EndArray)
// {
// attributes = attribList.ToArray();
// break;
// }
return(w.ToString());
}
private void AppendWrite(SourceWriter w, string typeName, List <JensonPropertyInfo> propertiesInfo)
{
// WRITE
// Relevant options
// - PropertyNameCaseInsensitive
// - IgnoreNullValues
// - IgnoreReadOnlyProperties
w.Line($"public override void Write(Utf8JsonWriter writer, {typeName} value, JsonSerializerOptions options)");
w.Line("{");
w.Indent();
w.Line("writer.WriteStartObject();");
w.Line();
for (var i = 0; i < propertiesInfo.Count; i++)
{
var p = propertiesInfo[i];
if (!p.ShouldSerialize)
{
continue;
}
var writeValueString = p switch
{
//_ when p.IsArray => GenerateWriteArray(p),
_ when p.IsString ||
p.IsBoolean ||
p.IsDateTime ||
p.IsDateTimeOffset ||
p.IsGuid => $"writer.WriteString(_{p.Name}Name, value.{p.Name});",
_ when p.IsByte ||
p.IsDecimal ||
p.IsDouble ||
p.IsInt16 ||
p.IsInt32 ||
p.IsInt64 ||
p.IsSByte ||
p.IsSingle ||
p.IsUInt16 ||
p.IsUInt32 ||
p.IsUInt64 => $"writer.WriteNumber(_{p.Name}Name, value.{p.Name});",
_ => $"JsonSerializer.Serialize(writer, value.{p.Name}, options);"
};
if (p.IsReadOnly)
{
w.Line($"if (!options.IgnoreReadOnlyProperties)");
w.Line("{");
w.Indent();
}
if (p.ShouldSerializeFunction != null)
{
w.Line($"if (value.{p.ShouldSerializeFunction}())");
w.Line("{");
w.Indent();
}
if (p.CanBeNull)
{
w.Line($"if (!(options.IgnoreNullValues && value.{p.Name} is null))");
w.Line("{");
w.Indent();
}
w.Line(writeValueString);
if (p.CanBeNull)
{
w.Dedent();
w.Line("}");
}
if (p.ShouldSerializeFunction != null)
{
w.Dedent();
w.Line("}");
}
if (p.IsReadOnly)
{
w.Dedent();
w.Line("}");
}
}
w.Line();
w.Line("writer.WriteEndObject();");
w.Dedent();
w.Line("}");
}
private void AppendRead(SourceWriter w, string typeName, List <JensonPropertyInfo> propertiesInfo)
{
// READ
// Relevant options:
// - IgnoreNullValues
// - ReadCommentHandling
// - AllowTrailingComments
w.Line($"public override {typeName} Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)");
w.Line("{");
w.Indent();
w.Line("if (reader.TokenType != JsonTokenType.StartObject) throw new JsonException(\"Expected start of object.\");");
w.Line();
foreach (var p in propertiesInfo.Where(p => p.ShouldDeserialize))
{
// variables to hold content
w.Line($"{p.TypeName} {p.Name} = default;");
}
w.Line();
w.Line("while (reader.Read())");
w.Line("{");
w.Indent();
w.Line("if (reader.TokenType == JsonTokenType.EndObject)");
w.Line("{");
w.Indent();
// Construct and return the read object
w.Line($"return new {typeName}");
w.Line("{");
w.Indent();
foreach (var p in propertiesInfo.Where(p => p.ShouldDeserialize))
{
w.Line($"{p.Name} = {p.Name},");
}
w.Dedent();
w.Line("};");
w.Dedent();
w.Line("}");
w.Line();
w.Line("if (reader.TokenType != JsonTokenType.PropertyName) throw new JsonException($\"Expected property name, but got {reader.TokenType}.\");");
w.Line();
var firstBranchHandled = false;
for (var i = 0; i < propertiesInfo.Count; i++)
{
var p = propertiesInfo[i];
if (!p.ShouldDeserialize)
{
continue;
}
// Check against properties
if (firstBranchHandled)
{
w.Write($"else ");
}
firstBranchHandled = true;
// TODO options.PropertyNameCaseInsensitive
// TODO options.PropertyNamingPolicy
w.Line($"if (reader.ValueTextEquals(_{p.Name}Name))");
w.Line("{");
w.Indent();
var tryReadValue = p switch
{
//_ when p.IsArray => GenerateReadArray(p),
_ when p.IsString => $"if (!reader.Read()) throw new JsonException();\n{p.Name} = reader.GetString();",
_ when p.IsBoolean => GenerateReadBoolean(p),
_ when p.IsByte => $"if (!reader.Read() || !reader.TryGetByte(out {p.Name})) throw new JsonException();",
_ when p.IsDateTime => $"if (!reader.Read() || !reader.TryGetDateTime(out {p.Name})) throw new JsonException();",
_ when p.IsDateTimeOffset => $"if (!reader.Read() || !reader.TryGetDateTimeOffset(out {p.Name})) throw new JsonException();",
_ when p.IsDecimal => $"if (!reader.Read() || !reader.TryGetDecimal(out {p.Name})) throw new JsonException();",
_ when p.IsDouble => $"if (!reader.Read() || !reader.TryGetDouble(out {p.Name})) throw new JsonException();",
_ when p.IsGuid => $"if (!reader.Read() || !reader.TryGetGuid(out {p.Name})) throw new JsonException();",
_ when p.IsInt16 => $"if (!reader.Read() || !reader.TryGetInt16(out {p.Name})) throw new JsonException();",
_ when p.IsInt32 => $"if (!reader.Read() || !reader.TryGetInt32(out {p.Name})) throw new JsonException();",
_ when p.IsInt64 => $"if (!reader.Read() || !reader.TryGetInt64(out {p.Name})) throw new JsonException();",
_ when p.IsSByte => $"if (!reader.Read() || !reader.TryGetSByte(out {p.Name})) throw new JsonException();",
_ when p.IsSingle => $"if (!reader.Read() || !reader.TryGetSingle(out {p.Name})) throw new JsonException();",
_ when p.IsUInt16 => $"if (!reader.Read() || !reader.TryGetUInt16(out {p.Name})) throw new JsonException();",
_ when p.IsUInt32 => $"if (!reader.Read() || !reader.TryGetUInt32(out {p.Name})) throw new JsonException();",
_ when p.IsUInt64 => $"if (!reader.Read() || !reader.TryGetUInt64(out {p.Name})) throw new JsonException();",
_ => $"{p.Name} = JsonSerializer.Deserialize<{p.TypeName}>(ref reader);"
};
w.Line(tryReadValue);
w.Dedent();
w.Line("}");
}
// handle no matching properties
if (firstBranchHandled)
{
w.Write("else");
w.Write("{");
w.Indent();
}
// TODO handle complex values (using Skip)
w.Line("if (!reader.Read()) throw new JsonException();");
if (firstBranchHandled)
{
w.Dedent();
w.Write("}");
}
w.Dedent();
w.Line("}");
w.Line();
w.Line("throw new JsonException(\"Missing close object token. Invalid JSON.\");");
w.Dedent();
w.Line("}");
}
private void GenerateTypeSerializer(JensonContext context, SourceWriter w, INamedTypeSymbol t)
{
AppendImports(w);
w.Line();
var ns = t.ContainingNamespace;
var nsString = ns.Name;
ns = ns.ContainingNamespace;
while (!ns.IsGlobalNamespace)
{
nsString = ns.Name + "." + nsString;
ns = ns.ContainingNamespace;
}
w.Line($"namespace {nsString}");
w.Line("{");
w.Indent();
var typeName = t.Name;
var declKeyword = t.TypeKind == TypeKind.Class ? (t.IsRecord() ? "record" : "class") : "struct";
w.Line($"[JsonConverter(typeof({typeName}Converter))]");
w.Line($"public partial {declKeyword} {typeName} {{ }}");
var propertiesInfo = ExtractPropertyInfo(context, t, typeName);
w.Line($"public class {typeName}Converter : JsonConverter<{typeName}>");
w.Line("{");
w.Indent();
var typeDiscriminatorAttr = t.GetAttributes()
.FirstOrDefault(attr =>
SymbolEqualityComparer.Default.Equals(
attr.AttributeClass,
context.JensonTypeDiscriminatorAttribute));
if (typeDiscriminatorAttr is not null)
{
var discrPropName = (string)typeDiscriminatorAttr.ConstructorArguments[0].Value;
var discrFun = (string)typeDiscriminatorAttr.ConstructorArguments[1].Value;
var discrProp = propertiesInfo.First(p => p.Name.Equals(discrPropName));
WriteTypeDiscriminatorConverterBody(w, typeName, discrProp, discrFun);
}
else
{
foreach (var p in propertiesInfo)
{
// TODO When property naming policy is set this won't necessarily match
// UTF-8 json variable names. We should take JsonSerializerOptions into account.
// Relevant props:
// - PropertyNameCaseInsensitive
// - PropertyNamingPolicy
// TODO use utf8 string literals when available
w.Line($"private static readonly byte[] _{p.Name}Name = Encoding.UTF8.GetBytes(\"{p.JsonName ?? p.Name}\");");
}
w.Line();
AppendRead(w, typeName, propertiesInfo);
w.Line();
AppendWrite(w, typeName, propertiesInfo);
}
w.Dedent();
w.Line("}"); // class
w.Dedent();
w.Line("}"); // namespace
Debug.Assert(w.Indentation == 0);
}
