多租户Rails模型继承

Question

My multi-tenant "Customer" model represents data from multiple tables in a "org_#{current_user.org.id}_customers" pattern (ie org_1_customers, org_2_customers, etc). I'm using RequestStore gem to store current_user's ORG_ID.

So, the problem is that to access data of CURRENT organization, I have to explicitly call "Customer.org" (ie Customer.org.where(...).load). Which requires rewriting A LOT of code, and remembering to add "org" every time I access the data.

MY QUESTION IS: Is there a way to make it so that I could access "Customer.org" by calling "Customer", so I would use "Customer" for current tenant's/org's customers, and "Customer.select_org(7)" for other tenant's/org's customers?

class ApplicationController < ActionController::Base
    before_filter :find_organization

    private
    def find_organization
        RequestStore[:current_org] = current_user ? current_user.org : nil
    end
end

class SegregatedMultitenantModel < ActiveRecord::Base
    self.abstract_class = true

    def self.select_org(org_id)
        @subdomain_classes ||= {}
        unless @subdomain_classes[org_id]
            @subdomain_classes[org_id] ||= Class.new(self)
            @subdomain_classes[org_id].table_name = "org_#{org_id}_#{self.table_name}" # This needs sanitizing, of course
            @subdomain_classes[org_id].reset_column_information
        end

        @subdomain_classes[org_id]
    end

    def self.org
        if RequestStore[:current_org].nil?
            raise "No Organization Selected For #{self.table_name}"
        else
            self.select_org(RequestStore[:current_org].id)
        end
    end
end

class Customer < SegregatedMultitenantModel
end

PS My application does require multiple Customer tables due to differences in table fields between tenants!

Answer 1

I've come up with a solution! It scopes the rows by convention anywhere in the app and I'm satisfied with it:

# Returns first row from "org_#{current_user.org.id}_customers" table
MT::Customer.first

# Returns first row from "org_3_customers" table
MT::Customer.select_org(3).first

To Do this, first, I segregated the "scoping" into a class:

class MT

    @@segregated_organization_models = {}

    def self.init(organizations, current_org, *options)
        organizations.each do |org|
            options[0][:segregated_models].each do |class_object|
                # Create new model class
                @@segregated_organization_models[org.id] ||= {}

                a = Class.new(class_object)
                @@segregated_organization_models[org.id][class_object.to_s.to_sym] = a

                # Set correct table name
                @@segregated_organization_models[org.id][class_object.to_s.to_sym].table_name = "org_#{org.id}_#{class_object.table_name}"

                # Set default model class to current organization's model class
                if org.id === current_org.id
                    self.const_set(class_object.to_s.to_sym, @@segregated_organization_models[org.id][class_object.to_s.to_sym])
                end
            end
        end
    end
end

while getting rid of the RequestStore gem and model logic in favor of the controller:

class ApplicationController < ActionController::Base
    before_filter :find_organization

    private
    # Multitenancy helpers

    def find_organization
        MT.init(Organization.all, current_user.org, 
            segregated_models: [
                ArticleCategory, Article, CustomArticleField,
                Customer, CustomerChange, CustomerLedgerItem
            ]
        )
    end
end

Model inheritance is still there:

class SegregatedMultitenantModel < ActiveRecord::Base
    self.abstract_class = true

    def self.select_org(org_id)
        MT.class_variable_get(:@@segregated_organization_models)[org_id][self.to_s.demodulize.to_sym]
    end
end

class Customer < SegregatedMultitenantModel
    self.abstract_class = true
    self.table_name = "customers"
end

Thanks a lot to an anonymous commenter who since deleted his response. Please don't delete your good responses with useful information! I have nothing to upvote. Lol.