Ajax and RJS

Slide 1: Ajax and RJS

Slide 2: Yes, Macs Rule

Slide 3: Ajax • mini web request from javascript • used to update pieces of content in page

Slide 4: When NOT to use AJAX • when the action is related to navigation • when there is another AJAX call inside that action (will get very complicated)

Slide 5: Cons of AJAX • can slow down a page just as easy as speed up a page • explosion of partials

Slide 6: Pros of AJAX • when done well, it will make the user experience much better • saves server traffic and potentially load • and...

Slide 7: It’s cool.

Slide 8: How does it work? Something like this: You always need a library.

Slide 9: Using PrototypeJS new Ajax.Updater('my_div', '/items'); text, partial or template from server new Ajax.Request('/items') javascript from server

Slide 10: Ruby Java Script Controller: RJS template:

Slide 11: JS Generating Methods • page is the virtual page object where you can write javascript to.

Slide 12: Inline RJS • no template • in the controller

Slide 13: Rails’ Helpers

Slide 14: Using a Spinner • link_to_remote_submit already has a spinner. • put a spinner onclick, not on the callbacks • disable the spinner onComplete or on content update

Slide 15: spin_div Spinner is created in the container and gets reset when container gets updated.

Slide 16: Status Notice JS

Slide 17: Alternative and Related Techniques

Slide 18: JSON

Slide 19: Cross-Server JS

Slide 20: Comet, AJAX' big brother synchronous VS asynchronous <%= periodically_call_remote %> sucks push javascript from server, using a flash socket

Slide 21: copyleft dominiek.com