Fires before a network request is made to retrieve the Json text which specifies a node's children.
Parameters: self - this Parameters: node - the node false to cancel
Fires when the node has been successfuly loaded.
Parameters: self - this Parameters: node - the node Parameters: response - the response text containing the data from the server
Fires if the network request failed.
Parameters: self - this Parameters: node - the node Parameters: response - the response containing the data from the server