Does anyone know if its possible to create a model instance and apply the ID and any other attributes without having to load it from the database? I tried doing this, but the associations are not fetched from the database:( Any ideas?
EDIT
What I want to accomplish is simply this:
This is where I am stuck, what I've been doing is creating a Model.new object and setting each of the params manually. This works, but it treats the instantiated model object as a new record. There has got to be an intermediate subroutine in ActiveRecord that does the attribute setting.
I solved the problem by doing the following.
Create a new model class which extends the model class that I want to have cached into memory.
Set the table_name of the new class to the same one as the parent class.
Create a new initialize method, call the super method in it, and then allow a parameter of that method to allow for a hash variable containing all the properties of the parent class.
Overload the method new_record?
and set that to false
so that the associations work.
Here's my code:
class Session < User
self.table_name = 'users'
METHODS = [:id, :username] # all the columns that you wish to have in the memory hash
METHODS.each do |method|
attr_accessor method
end
def initialize(data)
super({})
if data.is_a?(User)
user = data
data = {}
METHODS.each do |key|
data[key] = user.send(key)
end
else
data = JSON.parse(data)
end
data.each do |key,value|
key = key.to_s
self.send(key+'=',value)
end
end
def new_record?
false
end
end
The memcached gem will allow you to shove arbitrary Ruby objects into it. This should all get handled for you transparently, if you're using it.
Otherwise, take a look at ActiveRecord::Base#instantiate to see how it's done normally. You're going to have to trace through a bunch of rails stack, but that's what you get for attempting such hackery!
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