Extract all images out from each node in content type

Question

Every time a new node is published within a single content type, I wish to extract (not remove) all the images out from that node's body and save the URL(s) of the images in the database. I will then use the URLs to make a slideshow of the images on a separate node.

I have three questions:

1. Which hook runs right before a node is published?
2. What's the best way of saving those URLs in the database?
3. Which Drupal function do I use to retrieve those URLs from the database?

Answer 1

Which book runs right before a node is published?

• hook_node_update($node) The hook is invoked after the node is inserted/updated in the node table

What's the best way of saving those URLs in the database?

• It totally depends upon your needs, Simply you will have to save in database in your own table(s).

Which Drupal function do I use to retrieve those URLs?

• It is not clear from where you want to retrieve. Database or Node Body.
  • For database you need to focus on Database abstraction layer
  • For Node body, you will have to parse some way e.g. PHP Simple Dom Parser