We're looking at developing a CCK-based solution for a petition website, where we have Petitions and Petitioners as separate node types linked together in a parent-child relationship.
One good example of a parent-child node relationship is the book module. This is very easy to implement using CCK's nodereference field type and you can even filter it according to node type. However, it still ultimately requires that the user to select the parent node from a drop-down or an autocomplete field. So, we need a way of automatically supplying the nid of the parent to the child's creation form.
Options, as far as I can tell:
1. Pull the referring URL when the child node form is created, and use it after submission to pull the nid out and place it in a nodereference field. This relies on the fact that the user visits the parent node immediately before visiting the child node creation page.
2. Pass the nid to the child node creation form as an argument or via a specialized URL. This would involve modifying function mapping so that a custom link like ?q=node/add/child/1337 would pull up the creation form and allow the form to pull the nid (1337) from the URL. This is more robust than the previous solution in that it is not reliant on a particular series of events.
Does anyone have any thoughts on how this might be accomplished?