[Catalyst] Prototype help

[samwyse]

On 7/25/05, Alan Humphrey <alan.humphrey at comcast.net> wrote:
> All – 
> This list has been a lifesaver in the past, I'm hoping it can come through
> again.  I'm trying to use Prototype/Ajax and I'm running into a brick wall. 
> Here's the (simplified) scenario: 
>
> User comes to a page with a form with two entry fields.  One field is ISBN,
> the other is Title. 
>
> User enters an ISBN.  On tabbing out of the field we do a look up to see if
> the ISBN is already on file. 
> 
> If the ISBN is on file we return the title and display it in the Title
> field.  Otherwise we display a message above the title field asking for
> input. 
>
> After making changes/additions the user pressing the "save" button and the
> form is processed normally, saving the data to the database. 
>
> Part of my problem is that I'm new to JavaScript.  However, I have figured
> out how to declare a JS function and get it called from an 'onchange' event.
>  So far so good.  My function extracts the current ISBN value from the form.
>  Now: 
>             1 – How do I get that value passed to the server? 
>             2 – What does my server function have to do to return data? 
>             3 – How do I define the callback to deal with the returned data?
> I see function names in Prototype that look promising, e.g.
> update_element_function, but I haven't been able to figure out how to string
> them all together to get the job done. 
> 
> Pointers, help, advice – all are welcome! 

HTML::Prototype is certainly one way to go, but if you are looking for
something simpler you can also try SACK: 
http://twilightuniverse.com/2005/05/sack-of-ajax/