I’m a RoR beginner and I’m trying to make a gem that can “intercepts”
all
action from my controllers.
I would like to do something like that:
class ApplicationController < ActionController::Base
include MyGem
end
class MyController < ApplicationController
do_something_to :some_attribute
def index
respond_with(@some_attribute)
end
end
In each call of index or other action from MyController, I want that
MyGem
execute “do_something_to” modifying the value of “some_attribute”. Is it
possible?
Can you give an example of this working, please? I don’t understand what
you mean by “the attribute that was passed”. What modifications is it
going
to make?
Thanks for your help Dheeraj, but I’m trying to do something like
Responders.
Responders has a respond_to :html in controllers, that is used in each
action call to respond_with.
The thing is: call a specific method that is located inside my gem for
every action call. This method should be able to modify the attribute
that
was passed.
class ApplicationController < ActionController::Base
include MyGem
end
class TasksController < ApplicationController
injector_to :task
def show
respond_with(@task)
end
end
When the action ‘show’ is called, the “injector_to” should inject the @task
for me.
In other words, injector_to makes “Task.find(params[id])” for me in this
case.
Other example: If I have this action →
def create
respond_with(@task)
end
the injector_to should do the hard work, instantiating the @task and
saving
it.
OK, so you’re trying to automate the default behaviour for a standard
controller without using scaffolding? That makes sense.
Two methods spring to mind.
A generic controller than handles the methods that other controllers
inherit from. You then set the variable name and class in each child
controller, maybe via overloaded methods or through your injector_to
method.
Your gem adds injector_to to ActiveController. When called it
dynamically adds the standard methods to the controller. You then patch
ActiveController so rather than looking for the “show” method, it looks
for
“injected_show”, etc, which calls the scaffold code, then calls the
controller-specific “show” method if there is one. That’s the nicest way
of
doing it from an end-user point of view.
I actually quite like this idea. If you want some help writing them Gem,
let me know offlist and I’ll happily help.
#1 seems to be the easiest, but #2 is the best solution.
Here’s my view of how this can work:
class TasksController < ApplicationController
# Specify which class has the generic scaffolding methods
scaffold :my_custom_scaffold_class
# or we bundle a generic class with the gem
scaffold
# Overriding is possible
def show(id)
# instance variable is already injected by our gem
# do something with the @task
end
end
or even
class ApplicationController < ActionController::Base
scaffold
end
to propagate to all controllers which inherit from
ApplicationController.
