Rails: Scaffold to automatically do one-to-many relationship

Question

Not sure if I'm reading this right, but it seems like Scaffold will not do a one-to-many relationship in its entirety. For instance, if I create messages with scaffold and then I want comments on those messages (one message -> many comments), I have to go through and change everything. For instance, I have to change this in the comment's new view

<% form_for(@comment) do |f| %>

to this

<% form_for([@message, @comment]) do |f| %>

and then change the Action to set up the @message var... amongst other things.

This cannot currently be done automatically with Scaffold, right?

Answer 1

Yes. Scaffold works for a model and related controller. It does not take care of or work with relationships.

Scaffold's primary objective is to get CRUD going on a model using a controller and related views. That's all. Any other requirement like relationships has to be coded manually.

Answer 2

Scaffolds are scaffolds. When you want anything other than a CRUD on a table (which is what a scaffold is/does), you need to alter the generated scaffolding code, or roll your own.

Answer 3

This is true, but, it's not the end of the story. There are at least two alternatives to Scaffold that both work quite well and automatically pick up on relationships between classes (based on your ActiveRecord relationship indicators like has_many). One of these alternatives is Streamlined and the other is ActiveScaffold.

They're mainly helpful for entering in data that your system requires that is not user entered data. For example, I use them for administrative tasks on tables where there's no point in building a complete UI for CRUD when one of the scaffold alternatives will do the job just fine for a seldom used feature. You wouldn't want to use them for comments on messages though.

Answer 4

Note that there are projects like Hobo for Rails which allow you to keep your fields and associations within the model itself. You can't scaffold associations, but it's pretty close.

You end up paying for this sugar by having a lot more of the application built behind your back. Instead of rolling your own, you're usually subtracting out what you need from a large bank of prebuilt behaviors.