I am working on a custom module based on ISBN2node that extends it for a specific content type on my site. ISBN2node is at https://github.com/leeksoup/ISBN2node
The point I'm confused about is regarding the functions for isbnreview_title_form, which are defined in isbn2node.module. There is a form builder function (isbnreview_title_form) and a submit handler (isbnreview_title_form_submit) but no validate function. This form begins with the user entering some keywords, and once those are submitted, it rebuilds the form with a list of book options for the user to choose from. Then once the user picks one and hits "Fetch" (the submit button), the module goes off and fetches the book data from the selected DB and populates a node add form.
What I don't understand is, what makes it go from the Fetch submit to the node add form? Where is it specified where to go/ what to do after this submit button is pressed?
For that matter, I don't see how the data for the selected option ends up in the node add form. I see that the isbnreview_form_alter hook implementation populates the form, but it's pulling the data from where it is saved in the config settings, but I only see it getting saved in isbnreview_add_form_submit (for an ISBN search, not a title/keyword search) and isbnreview_add_manual (which saves only the ISBN for a manual node entry). It is not saved in the isbn2node_title_form* functions.
Help?
Figured it out. Both the builder and submit handler functions have two conditional blocks. One block happens on the first pass through the form, and the other block on the second pass. The submit handler sets up rebuild values for the form at the end of the first pass, which sends it to the builder again, and then its value gets sent to the other part of the submit handler when the user hits submit.
Also, unrelatedly, the block styles aren't working for me (grayed out) today in the Forum's CKE plugin.