NYCPHP Meetup

[Steve Manes]

tedd wrote:
> Now, what I am asking is not how ajax communication with the server can 
> be used, but rather is there anything beyond that which ajax can provide?
> 
> Another way of asking this question is, "Besides not triggering a 
> refresh, what can ajax do that php can not?"

You're right: nothing.  But just focusing on the get/post mechanics as a 
baseline for comparison is kinda reducing the question to, "is there 
anything client/server can do that client/server can't do?"

Ajax is just a tool.  My table saw cuts wood one way, my compound miter 
saw another, my radial arm saw another.  Technically, they can all do 
the same cuts.  It's just a lot nicer (and safer) to use a table saw to 
rip panels and an SCMS to crosscut long lumber.  And technically most of 
what they can do can be done with a manual carpenter's saw and a bottle 
of glucosomine.

Here's an example where Ajax is the better tool.  I'm building a medical 
application which has a desktop containing seven collapsible DIVs.  Each 
of those DIVs can also have at least two states: view and edit.  Some 
have three, with a result list (like a list of current insurance 
policies).  That's the way the client wanted it.

Necessarily, there are a lot of queries going on to populate all the 
DIVs on that page: patient demographic info, insurance info, guarantor 
info, family relations info, a list of historical referrals, 
appointments, patient transportation, etc.  So repopulating that page 
sucks the air out of the database.  If I correct a start date for an 
insurance policy do I really want to repopulate that entire desktop 
page?  Heck no.

The better solution is to submit just the form that matters and update 
just those DIVs where that update has data relevance.  Mostly it's two 
just queries instead of a dozen: put_foo and get_foo, with Ajax 
arbitrating which display elements get updated.