public XamlIlNodeEmitResult Emit(IXamlIlAstNode node, XamlIlEmitContext context, IXamlIlEmitter ilgen)
{
if (!(node is XamlIlMarkupExtensionNode me))
{
return(null);
}
XamlIlNeedsParentStackCache.Verify(context, node);
var prop = context.ParentNodes().OfType <XamlIlPropertyAssignmentNode>().FirstOrDefault();
var needProvideValueTarget = me.ProvideValue.Parameters.Count != 0 &&
context.RuntimeContext.PropertyTargetObject != null &&
prop != null;
void EmitPropertyDescriptor()
{
if (context.Configuration.TypeMappings.ProvideValueTargetPropertyEmitter
?.Invoke(context, ilgen, prop.Property) == true)
{
return;
}
ilgen.Ldstr(prop.Property.Name);
}
context.Emit(me.Value, ilgen, me.Value.Type.GetClrType());
if (me.ProvideValue.Parameters.Count > 0)
{
ilgen
.Emit(OpCodes.Ldloc, context.ContextLocal);
}
if (needProvideValueTarget)
{
ilgen
.Ldloc(context.ContextLocal);
EmitPropertyDescriptor();
ilgen
.Stfld(context.RuntimeContext.PropertyTargetProperty);
}
ilgen.EmitCall(me.ProvideValue);
if (needProvideValueTarget)
{
ilgen
.Ldloc(context.ContextLocal)
.Ldnull()
.Stfld(context.RuntimeContext.PropertyTargetProperty);
}
return(XamlIlNodeEmitResult.Type(0, me.ProvideValue.ReturnType));
}
public XamlIlNodeEmitResult Emit(IXamlIlAstNode node, XamlIlEmitContext context, IXamlIlEmitter codeGen)
{
if (!(node is XamlIlMarkupExtensionNode me))
{
return(null);
}
XamlIlNeedsParentStackCache.Verify(context, node);
var ilgen = codeGen;
var so = context.Configuration.WellKnownTypes.Object;
var ptype = me.Manipulation?.ParametersWithThis[1] ?? me.Property.PropertyType;
var rtype = me.ProvideValue?.ReturnType ?? me.Value.Type.GetClrType();
var needProvideValueTarget = me.ProvideValue != null &&
me.ProvideValue.Parameters.Count != 0 &&
context.RuntimeContext.PropertyTargetObject != null &&
me.Property != null;
void EmitPropertyDescriptor()
{
if (me.Property == null)
{
ilgen.Ldnull();
}
else if (context.Configuration.TypeMappings.ProvideValueTargetPropertyEmitter
?.Invoke(context, codeGen, me.Property) == true)
{
return;
}
else if (me.Property is XamlIlAstAttachedProperty)
{
ilgen.Ldtoken(me.Property.Getter ?? me.Property.Setter)
.Emit(OpCodes.Box, context.Configuration.TypeSystem.GetType("System.RuntimeMethodHandle"));
}
else
{
ilgen.Ldstr(me.Property?.Name);
}
}
using (var resultLocalContainer = context.GetLocal(rtype))
{
var resultLocal = resultLocalContainer.Local;
using (var targetObjectLocal = needProvideValueTarget ? context.GetLocal(so) : null)
{
if (needProvideValueTarget)
{
ilgen
.Dup().Stloc(targetObjectLocal.Local);
}
context.Emit(me.Value, codeGen, me.Value.Type.GetClrType());
if (me.ProvideValue?.Parameters.Count > 0)
{
ilgen
.Emit(OpCodes.Ldloc, context.ContextLocal);
}
if (needProvideValueTarget)
{
ilgen
.Ldloc(context.ContextLocal)
.Ldloc(targetObjectLocal.Local)
.Stfld(context.RuntimeContext.PropertyTargetObject)
.Ldloc(context.ContextLocal);
EmitPropertyDescriptor();
ilgen
.Stfld(context.RuntimeContext.PropertyTargetProperty);
}
if (me.ProvideValue != null)
{
ilgen
.Emit(OpCodes.Call, me.ProvideValue);
}
ilgen
.Emit(OpCodes.Stloc, resultLocal);
if (needProvideValueTarget)
{
ilgen
.Ldloc(context.ContextLocal)
.Ldnull()
.Stfld(context.RuntimeContext.PropertyTargetObject)
.Ldloc(context.ContextLocal)
.Ldnull()
.Stfld(context.RuntimeContext.PropertyTargetProperty);
}
}
// At this point we have the target object at the top of the stack and markup extension result in resultLocal
var exit = ilgen.DefineLabel();
// This is needed for custom conversions of Binding to object
var customTypes = context.Configuration.TypeMappings.MarkupExtensionCustomResultTypes;
// This is needed for properties that accept Binding
if (
me.Property != null &&
context.Configuration.TypeMappings.ShouldIgnoreMarkupExtensionCustomResultForProperty !=
null)
{
customTypes = customTypes.Where(ct =>
!context.Configuration.TypeMappings
.ShouldIgnoreMarkupExtensionCustomResultForProperty(me.Property, ct))
.ToList();
}
if (customTypes.Any() && !rtype.IsValueType)
{
void EmitCustomActionCall()
{
EmitPropertyDescriptor();
codeGen
.Emit(OpCodes.Ldloc, context.ContextLocal)
.Emit(OpCodes.Ldloc, resultLocal);
if (rtype.IsValueType)
{
codeGen.Emit(OpCodes.Box, rtype);
}
codeGen
.Emit(OpCodes.Call, context.Configuration.TypeMappings.MarkupExtensionCustomResultHandler)
.Emit(OpCodes.Br, exit);
}
// Skip conversion attempts and call custom conversion directly
if (customTypes.Any(ct => ct.IsAssignableFrom(rtype)))
{
EmitCustomActionCall();
ilgen.MarkLabel(exit);
return(XamlIlNodeEmitResult.Void(1));
}
var callCustomLabel = ilgen.DefineLabel();
var afterCustomLabel = ilgen.DefineLabel();
foreach (var ct in customTypes)
{
codeGen
.Ldloc(resultLocal)
.Isinst(ct)
.Brtrue(callCustomLabel);
}
ilgen
.Br(afterCustomLabel)
.MarkLabel(callCustomLabel);
EmitCustomActionCall();
ilgen.MarkLabel(afterCustomLabel);
}
TypeSystemHelpers.EmitConvert(context, node, rtype, ptype,
lda => ilgen.Emit(lda ? OpCodes.Ldloca : OpCodes.Ldloc, resultLocal));
// Call some method either on the target or on target's property
if (me.Manipulation != null)
{
// {target}.{Property}.{Method)(res)
if (me.Property != null)
{
using (var res = context.GetLocal(ptype))
ilgen
.Emit(OpCodes.Stloc, res.Local)
.EmitCall(me.Property.Getter)
.Emit(OpCodes.Ldloc, res.Local);
}
me.Manipulation.Emit(context, ilgen, true);
}
// Call property setter on the target
else
{
ilgen.EmitCall(me.Property.Setter);
}
ilgen.MarkLabel(exit);
}
return(XamlIlNodeEmitResult.Void(1));
}