Getting content: AJAX vs. "Regular" HTTP call

Question

I like that, these days, we have an option for how we get our web content from the server: we can make an old-style HTTP request (with its own URL in the browser) or we can make an AJAX call and replace parts of the DOM on the fly.

My question is this: how do you decide which method to use when there's an option to use either?

In the "old days" we'd have to redraw the entire page (including the parts that didn't change) if we wanted to show updated content. Now that AJAX has matured we don't need to do that any more; we could, conceivably, render a "page" once and just update the changing parts as needed. But what would be the consequences of doing so? Is there a good rule of thumb for doing a full-page reload vs a partial-page reload via AJAX?

Answer 1

If you want people to be able to bookmark individual pages, use HTTP requests.

If you are changing context, use HTTP requests.

If you are dividing functionality between different pages for better maintainability, use HTTP requests.

If you want to maximize your page views, use HTTP requests.

Lots of good reasons to still use HTTP requests - Stack overflow is a wonderful example of those divisions between AJAX and HTTP requests. Figure out why each function is HTTP or AJAX and I'm sure you will derive lots more reasons when to use each.

Answer 2

My simple rule:

Do everything ajax, especially if this is an application not just pages of content. Unless people are likely to want to link to direct content, like in a blog. Then it is easier to do regular full pages.

Of course there are many blended combinations, it doesn't have to be one or the other completely.