What's the best Rails convention for this?

Let's say that you have a resource that is created and displayed entirely within the view of开发者_Python百科 another resource (eg. comments or tags). Should you still make it it's own resource, or would it be a better idea to make it a nested resource? Also, should you make use of virtual attributes?

I know this question is general, but I'm not looking for a specific answer, just a general explanation of when each technique is preferred.

Some general thoughts:

• Nesting and independent resources are not necessarily mutually exclusive.
• "created and displayed entirely within the view of another resource" is a strong statement that can end up not being true. For example, tags: do you ever want a list of all articles with a certain tag. that would not make sense nested.
• Nesting below the second or third level will begin to be more trouble then its worth. Some will say that even the first nesting is more trouble then its worth.
• For an app that has a single dominate resource the cost of adding other independent resources is proportionally higher. Small apps can get away with complexities that large apps cannot.
• If you don't have a good feel yet write a few resources each way. Answers will at best be justifies opinions it is probably best to develop you own through experience.

Generally speaking, it would be more useful to make it a nested resource. This is the more "RESTful" way. It will also give you access to the parent resource without having to specify it as a parameter. However, you do not want to nest a resource more than one level deep, as noted in the Rails routing guide.