Here is how I did something analogous for a Markdown renderer. The actual syntax in there is now several years old, but the basic idea should remain relevant.
It’s also not entirely out of the realm of possibility that you could do the entire thing with a single page - I have combined Add/Edit/View in the past, using readonly form inputs in the case of View and having a sentinel value in the backing business object (like id) to disambiguate Add/Edit. If we have an id, then we’re editing. If we don’t, we’re creating from scratch.