public Expression <BindingDelegate> CompileToDelegate(
CastedExpressionBindingProperty expression, DataContextStack dataContext)
{
var expr = BindingCompiler.ReplaceParameters(expression.Expression, dataContext);
expr = new ExpressionNullPropagationVisitor(e => true).Visit(expr);
expr = ExpressionUtils.ConvertToObject(expr);
return(Expression.Lambda <BindingDelegate>(expr, BindingCompiler.ViewModelsParameter, BindingCompiler.CurrentControlParameter));
}
public Expression <BindingUpdateDelegate> CompileToUpdateDelegate(ParsedExpressionBindingProperty binding, DataContextStack dataContext)
{
var valueParameter = Expression.Parameter(typeof(object), "value");
var expr = BindingCompiler.ReplaceParameters(binding.Expression, dataContext);
// don't throw exception, it is annoying to debug.
if (expr.NodeType != ExpressionType.Parameter &&
(expr.NodeType != ExpressionType.MemberAccess || (!expr.CastTo <MemberExpression>().Member.As <PropertyInfo>()?.CanWrite ?? false)) &&
expr.NodeType != ExpressionType.Index)
{
return(null);
}
var assignment = Expression.Assign(expr, Expression.Convert(valueParameter, expr.Type));
return(Expression.Lambda <BindingUpdateDelegate>(assignment, BindingCompiler.ViewModelsParameter, BindingCompiler.CurrentControlParameter, valueParameter));
}
public Expression <BindingUpdateDelegate> CompileToUpdateDelegate(ParsedExpressionBindingProperty binding, DataContextStack dataContext)
{
var valueParameter = Expression.Parameter(typeof(object), "value");
var body = BindingCompiler.ReplaceParameters(binding.Expression, dataContext);
body = ExpressionHelper.UpdateMember(body, valueParameter);
if (body == null)
{
return(null);
}
return(Expression.Lambda <BindingUpdateDelegate>(
body,
BindingCompiler.ViewModelsParameter,
BindingCompiler.CurrentControlParameter,
valueParameter));
}
