Expression Items(ContainerItemHandler handler)
{
// If the list is an empty element we won't read anything
var isEmpty = Expression.Variable(typeof(bool), "isEmpty");
// Generate the following code for the "next" expression:
// if (isEmpty)
// {
// return false;
// }
// else
// {
// while (reader.NodeType == XmlNodeType.Whitespace) reader.Read;
// do { reader.Read(); } while (reader.NodeType == XmlNodeType.Whitespace;
//
// if (reader.NodeType == XmlNodeType.Element) &&
// reader.LocalName != "Item")
// {
// throw new InvalidDataException();
// }
//
// return reader.XmlNode != XmlNodeType.EndElement;
// }
var whitespace = Expression.Equal(Reader.NodeType, Expression.Constant(XmlNodeType.Whitespace));
var next = Expression.Condition(isEmpty,
Expression.Constant(false),
Expression.Block(
ControlExpression.While(whitespace, Reader.Read()),
ControlExpression.DoWhile(Reader.Read(), whitespace),
Expression.IfThen(
Expression.AndAlso(
Expression.Equal(Reader.NodeType, Expression.Constant(XmlNodeType.Element)),
Expression.NotEqual(Reader.LocalName, Expression.Constant("Item"))),
ParsingError()),
Expression.NotEqual(Reader.NodeType, Expression.Constant(XmlNodeType.EndElement))));
return(Expression.Block(
new[] { isEmpty },
Expression.Assign(isEmpty, Reader.IsEmptyElement),
handler(next)));
}
public virtual Expression Apply(ITransform transform)
{
IEnumerable <TransformSchemaPair> transforms;
if (flatten && schema.HasBase)
{
// collect transform/schema pairs for all the bases
var flatteningParser = new FlatteningParser(Schema);
flatteningParser.Apply(transform);
transforms = flatteningParser.Transforms;
}
else
{
transforms = new[] { new TransformSchemaPair(transform, Schema) };
}
var state = Expression.Variable(typeof(byte), "state");
var requiredFields = RequiredFields.Variable("requiredFields");
var requiredFieldNames = GetRequiredFieldNames();
var stateMachine = CreateStateMachine(transforms, requiredFields);
return(Expression.Block(
new[] { state, requiredFields },
transform.Begin,
RequiredFields.Init(requiredFields, requiredFieldNames.Count),
Expression.Assign(state, Expression.Constant(stateMachine.InitialState)),
ControlExpression.While(
Expression.AndAlso(
Expression.Not(EOF),
Expression.NotEqual(state, Expression.Constant(stateMachine.FinalState))),
SwitchToken(stateMachine, state),
Expression.Label("endStateMachineLoop")),
VerifyRequiredFields(requiredFields, requiredFieldNames),
transform.End));
}