Recycled objects

rubyonrails-talk
1

Hi,

I am developing a Rails app where I need to pass an object around between views. I am doing this by sending each view the object_id, and then doing

@theObject = ObjectSpace._id2ref(params[:objid])

This is a really bad idea (and of course were you ever to have more
than one mongrel then the 2 requests could be server by completely
separate processes, which means that it would be completely impossible
for this to ever work).

There are two problems with this: One, it's not very elegant. Is
there a better way? Two, I get an intermittent error, "RangeError : 0xfooba4 is recycled object". I *suspect* this happens because my object is
getting garbage collected between views. Since it is an instance member of my controller object (I've also experimented with making it a class member), I feel this ought not to happen, but there it is.

A given instance of controller only lasts for one request. I suspect
you're running in dev mode, so classes are also reloaded after each
request.

Can anyone suggest a better method for persisting my object so all my views have access to it, and it doesn't get garbage
collected?

Serialize it and store the data in the db, memcached or even the
session.

Fred

2

Hmm, ok, I took him to mean views as, well, views. If you indeed mean between page requests, then yes, store them in the session or another persistent area. However, if you really do mean between separate views in during the same request, then :locals is what you want.

-Bill

Frederick Cheung wrote:

3

Most web apps do database reads on every request. If it is semi-static you can always use page or view caching if it turns out to be a bottleneck. For a web server the load must be very high (wrt request/ second) before the db becomes the bottleneck, especially for a Rails app.

Regarding sessions they (to me) seem to be what you want to use. There is not a problem with different users. The point of a session is that the web server creates a specific session for each user. So if you write session[:user_name] = params[:name] in a controller it will store different values for different web users. If the objects are large they should not be stored in the sessions, there are multiple articles around on this but I don't have any references handy.

If you need further tips, please specify more precisely what you want to store between requests.

Regards

Erik Lindblad