In a ColdBox request, form, URL, and remote (proxy request) variables are merged together into the request collection which is accessible via event.getCollection() or as the “rc” struct passed into every action in your handlers. Data needed to process that request can be added and retrieved from this collection at any time during the request as it is available to any layouts and views as well.
What you may not now however, is there is also a private request collection. This one also lives in the event object and can be accessed via event.getCollection(private=true) or as the “prc” struct that is also passed into each action.
So, what’s the difference between the regular request collection and the private request collection? Not much in the way of implementation. It’s all in how you use them to help organize your code. ColdBox best practices are to reserve the regular request collection for only form, URL, and remote variables as they were received from the client. More importantly, these are the incoming variables from your user that control how the request will process. A good example would be the productID variable coming into a product detail page.
The private collection is best used by everything else, especially if it has no direct bearing on how the page is processed. An example could be a service that the handler wants to pass along to the view, or a result set of data that will be used in outputting the view.
P.S. One of the reasons it’s ideal to only store items in the rc that control what displayed on the page is because ColdBox creates a hash of the rc at the beginning of your request which is used for event caching to ensure a different version of the event’s output is cached for each combination of incoming criteria.
ColdBox Platform Evangelist
Ortus Solutions, Corp