public IEnumerable <BindingPair <SqlStorageField <TEntity>, PropertyField> > GetBindingPairs(
SqlStorageModel <TEntity> sourceModel,
SqlEntityModel <TEntity> targetModel)
{
foreach (var targetField in targetModel.Fields)
{
var sourceField = sourceModel.Fields.FirstOrDefault(
q => q.TypeModelGraphPath.Path.SequenceEqual(targetField.TypeModelGraphPath.Path)
);
if (sourceField != null)
{
var bindingSource = new ModelFieldBindingSource <SqlStorageField <TEntity> >(
new[] { sourceField.FieldName },
sourceField
);
yield return(new BindingPair <SqlStorageField <TEntity>, PropertyField>(
bindingSource,
new ModelFieldBindingTarget <PropertyField>(targetField.TypeModelGraphPath.Path, targetField)
));
}
else if (targetField.FieldModel != null && targetField.FieldModel.Fields.Count > 0)
{
foreach (var pair in GetBindingPairs(sourceModel, targetField.FieldModel))
{
yield return(pair);
}
}
}
}
public bool TryPrepareForRead(ModelFieldBindingSource <TField> bindingSource)
{
var desiredGraphPosition = bindingSource.Path.Take(bindingSource.Path.Length - 1);
if (desiredGraphPosition.SequenceEqual(_currentPosition))
{
// no-op if already in position to read
return(true);
}
// todo: don't rely on exceptions here to control flow, it's naughty
try
{
// todo: optimize graph navigation
// for now we just seek to the top of the graph and descend back to where we want to be
// this can be done in fewer steps if the desired path and current path
// share a common root
SeekToTop();
SeekTo(desiredGraphPosition);
return(true);
}
catch
{
return(false);
}
}