[LRUG] REST and Associations

[Andrew Stewart]

> 2. What is the right way to do search? Are query strings still ok in
> urls? Is search a seperate controller?

I don't know about the 'right' way, but this is how I think of it:

As well as searching for things one can execute a search.  I.e.  
search can be a verb or a noun.

Think of TV cop-shows where the detectives want to look for a  
suspicious item in someone's house.  First the detectives need to go  
to a judge to get a search warrant.  The warrant describes the terms  
of the search they are permitted to do.

Second, the detectives go to the house, serve the warrant on the  
person and ransack the place.

After the trashing the person's house they take everything back to  
the lab for analysis.  But they don't find anything useful.  Then  
another detective who has been interviewing witnesses learns a clue  
which might mean that the first lot of detectives overlooked  
something in their search of the guy's house.

So the detectives return to the house with the same warrant and  
search it all over again.

Now, the warrant represents a search resource.  Its attributes  
describe a search which can be performed at any time.  Each time the  
detectives go the house and ransack it, they are getting results  
based on the the nature of the search described in the warrant.

The next day they go to a different judge and ask for a new warrant.   
This one allows them to search the garden too.  So off they go.

There are now two warrants (or search resources) describing different  
searches.  The results which the detectives get may or may not be the  
same.

Pre-REST I thought of searching in terms of a verb, i.e. calling an  
action in a controller with my ad hoc query parameters.

But now I think of creating a search as a noun.  This enables you to  
allow the user to create their own searches/queries in the GUI and  
save them.  For example, in a bug tracking application, you might  
allow a user to create reports like "All open bugs assigned to me"  
and "All high priority bugs which have been open for more than a  
month, oldest first."

Every time the user runs one of those reports, he gets the results  
back.  In practical terms, he calls GET on, say, query no. 2 and it  
returns the results to him.

So the resource is a Search.  The SearchesController has these  
actions: create (store a new query), delete (forget about it), update  
(modify a query), get (execute the search and return the results), etc.


> 3. Similarly what is the right way to do sorting/pagination? For
> example when I GET /posts I may want to only return the top ten in
> html - but what about in the xml respond_to do I return all of them or
> just ten? Is the idea that *exactly* the same resource(s) are
> returned, no matter the mime type or can _what_ is returned vary as
> well as _how_ it is returned?

I believe that exactly the same resources should be returned,  
regardless of MIME type.  In this case you have two queries: all and  
recent.

Hope all that helps.

Regards,
Andy Stewart