public JToken Traverse(JToken tree, TraversalStepOperation op, IEnumerator <string> keys, JToken data)
{
if (tree == null)
{
return(null);
}
if (GetStepType().IsAssignableFrom(tree.GetType()))
{
keys.MoveNext();
string key = keys.Current;
if (_child == null)
{
// End of the Traversal so do the set or get
switch (op)
{
case TraversalStepOperation.GET:
return(Get(tree, key));
case TraversalStepOperation.SET:
return(_traversr.HandleFinalSet(this, tree, key, data));
case TraversalStepOperation.REMOVE:
return(Remove(tree, key));
default:
throw new InvalidOperationException("Invalid op:" + op.ToString());
}
}
else
{
// We just an intermediate step, so traverse and then hand over control to our child
var optSub = _traversr.HandleIntermediateGet(this, tree, key, op);
if (optSub != null)
{
return(_child.Traverse(optSub, op, keys, data));
}
}
}
return(null);
}
/** * Allow subclasses to control how gets are handled for intermediate traversals. * * Example: we are a MapTraversal and out key is "foo". * We simply do a 'tree.get( "foo" )'. However, if we get a null back, or we get back * a data type incompatible with our child Traversal, what do we do? * * Overwrite or just return? */ public abstract JToken HandleIntermediateGet(ITraversalStep traversalStep, JToken tree, string key, TraversalStepOperation op);
/**
* Only make a new instance of a container object for SET, if there is nothing "there".
*/
public override JToken HandleIntermediateGet(ITraversalStep traversalStep, JToken tree, string key, TraversalStepOperation op)
{
var sub = traversalStep.Get(tree, key);
if ((sub == null || sub.Type == JTokenType.Null) && op == TraversalStepOperation.SET)
{
// get our child to make the container object, so it will be happy with it
sub = traversalStep.GetChild().NewContainer();
traversalStep.OverwriteSet(tree, key, sub);
}
return(sub);
}
