I am working to creating a wrapper for my existing application controllers.
For example, i have two controllers accepting similar set of parameters and similar methods.
Code is as below
class EmployeeController < ApplicationController def list end end class DepartmentController < ApplicationController def list end end end point would be http://localhost:3000/employee/list & http://localhost:3000/department/list
What is the best way to create wrapper controller and invoke either of the controllers action.
is this way correct, where we check certain parameters and create objects accordingly or are there better ways to do it
class WrapperController < ApplicationController def list if params["which"].eql?("employee") data = EmployeeController.new(params).create else data = DepartmentController.new(params).label end end end end point would be http://localhost:3000/wrapper/list
Any help would be appreciated. Thanks in advance.
4 Answers
Answers 1
This WrapperController sounds like a really bad idea. Especially instantiating another controller and calling a method on it. I don't recall seeing such pattern anywhere. Rails does a lot of magic around request/response cycle, so calling another controller will most likely break something later on. I am just guessing that cookies may not work, or rendering can be broken etc.
Anyway, what you probably want is better organise your business logic inside Rails application. As a starting point I strongly recommend reading this article. Based on limited information from your question it is hard to give a good answer for your particular case.
For example, you can implement a query object:
class EmployeesQuery def initialize(params) # initialize some internal variables end def list # write code for fetching employees based on passed params end end class DepartmentsQuery def initialize(params) # initialize some internal variables end def list # write code for fetching employees based on passed params end end class QueryFactory QUERIES = { "employee" => EmployeeQuery, "department" => DepartmentQuery } get self.get_query(resource) QUERIES[resource] || raise("Some exception") end end Now you can create a ListsController:
class ListsController < ApplicationController def index data = QueryFactory.get_query(params[:which]).list # render specific view based on requested resource # and rescue possible exception from get_query method end end And in config/routes.rb:
get "/:which/list" => "lists#index" This can be later extended with more resources and having separate query objects for each will make it more maintainable. The only problematic thing is how to render generated results, but you can use similar pattern for selecting correct template to render.
If you want to have similar pattern for creating objects, you should look at service object pattern. It is described in linked article.
Also you can kind solve your problem with much simpler way, just by changing config/routes.rb a little bit.
get "/:controller/list", to: :list It will route /employee/list to EmployeeController and /department/list to DepartmentController. And basically it will route to any valid controller, so maybe you want to tweak it a little bit and add some restrictions.
Hope that helps. Cheers.
Answers 2
Why shouldn't we just forward it with same request
class WrapperController < ApplicationController def list if params["which"].eql?("employee") controller = EmployeeController.new else controller = DepartmentController.new end controller.request = request controller.response = response controller.list end end Answers 3
You already have this with Application Controller, that's why its the parent controller. The standard way would be to add a before_action in ApplicationController that performs the check and then redirects to the proper controller.
class ApplicationController before_action :check_emp_or_dept def check_emp_or_dept if employee_params.fetch("which", "").eql?("employee") @employee = Employee.find employee_params['id'] redirect_to @employee else @department = Department.find department_params['id'] redirect_to @department end end protected # handle strong params according to what your model requires def department_params params.require(:department).permit(:param1, :param2) end # handle strong params according to what your model requires def employee_params params.require(:department).permit(:param1, :param2) end end Note this code above will need to be reworked to your specific setup for strong params. I would argue that it's not a good idea to create Employees/Departments blindly based on the passed params, although you can easily change the find methods above to "find_or_create_by" methods if you so choose.
Answers 4
You can do this easily in routing (i.e. routes.rb file) using constraints:
get '/wrapper/list', to: 'employee#list', constraints: lambda { |request| request.query_parameters["which"] == "employee" } get '/wrapper/list', to: 'department#list', constraints: lambda { |request| request.query_parameters["which"] != "employee" } 
0 comments:
Post a Comment