# Accessing one objects methods from within another object **URL:** \ **Category:** Ruby\ **Created:** [November 29, 2008, 6:44am UTC](https://www.ruby-forum.com/t/accessing-one-objects-methods-from-within-another-object/154420 "2008-11-29T06:44:06Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![scudco](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/aca169/32.png) [@scudco](https://www.ruby-forum.com/u/scudco)\ **Post date:** [November 29, 2008, 6:44am UTC](https://www.ruby-forum.com/t/accessing-one-objects-methods-from-within-another-object/154420/1 "2008-11-29T06:44:06Z")
Ive created a simple todo list app for the console and tried to implement mvc using my very very very limited mvc knowledge. In the app users can create single tasks. they can also group tasks with a similiar theme together into a project. I thought id learn more about mvc and oop than just reading or using some framework. So i have two basic class definitions class Project\_controller class Task\_controller Ive added basic CRUD functionality to them. But now they need to interact with one anohter in a few situations. For example, when a user wants to delete a project they might also want to delete the associated tasks with that project. So in project\_controller.delete() I want to be able to access the task objects delete method. I thought about passing the object itself as a parameter e.g class Project\_controller def delete a\_task\_controller #blah blah blah #user says yes delete the associated tasks a\_task\_controller.delete end but that doesnt seem pratical because if i start adding other controllers such as say “Category” i could end up with a huge parameter list I then thought about using initialize like this class Project\_controller def initialize a\_task\_controller @a\_task\_controller = a\_task\_controller end end but then ill also need to do the same with Task\_controller and that will lead to a run error due to the ole what comes first the chicken or the egg. task\_cntr = Task\_controller.new (proj\_cntr) #proj\_cntr doesnt exist yet so boom! proj\_cntr = Project\_controller.new (task\_cntr) #this is ok though Whats teh best way of doing this, is there a way i make all controller objects be able to access other controllers methods? Is the observer pattern useful here? Ive never used it but know a bit about it. Sorry if the titles vague. Im trying to develop a simple todo list console app and decided to try and use mvc principles with what limited knowledge of mvc i have. in the apps a user can define projects such as “Buy a new PC” and then assign new tasks to this project such as “Research Anandtech for best value parts”, “find cheapest price of parts on [froogle.com](http://froogle.com)”. Hence i have a projects controller class and a tasks controller class. At the moment they are defined as seperate classes but i can see now that they could inheirt from an abstract parent “Controller” class but at the time i didnt know what the common code would be as im a newb. Alls gone well as i created pretty much each respective items basic CRUD code and they didnt interact. However when it comes to deleting a project i realised that the user should be able to decide if they want to delete the tasks associated with it as well. I dont want to copy and paste my delete code from my tasks controller over the project controller as its duplication and contradicts oop. I want to be able to do just call the task controller objects delete method from within the project controller objects delete method. like class project\_controller def delete #choose project to delete project\_to\_delete = users\_choice() #now display the associated tasks with this project task\_controller\_object.display\_tasks\_for\_project(project\_to\_delete) #find out if user wants to delete tasks as well… user\_wants\_to\_delete = get\_response() if user\_wants\_to\_delete == true #use the task cntr object once again to do its own dirty work task\_controller\_object.delete(all\_tasks\_associated\_with\_this\_project) … … blah blah blah end ---
**Author:** ![scudco](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/aca169/32.png) [@scudco](https://www.ruby-forum.com/u/scudco)\ **Post date:** [November 29, 2008, 6:45am UTC](https://www.ruby-forum.com/t/accessing-one-objects-methods-from-within-another-object/154420/2 "2008-11-29T06:45:07Z")
sorry the bottom part of that mail was a previous version of my message, forgot to delete it ---
**Author:** ![scudco](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/aca169/32.png) [@scudco](https://www.ruby-forum.com/u/scudco)\ **Post date:** [November 29, 2008, 8:34am UTC](https://www.ruby-forum.com/t/accessing-one-objects-methods-from-within-another-object/154420/3 "2008-11-29T08:34:19Z")
Hi – On Sat, 29 Nov 2008, Adam A. wrote: > #user says yes delete the associated tasks > def initialize a\_task\_controller > proj\_cntr = Project\_controller.new (task\_cntr) #this is ok though > > Whats teh best way of doing this, is there a way i make all controller > objects be able to access other controllers methods? Is the observer > pattern useful here? Ive never used it but know a bit about it. It looks like you’re trying to accomplish the M part of MVC in the C part. You should think about having not just controller classes, but a Task class and a Project class. The Task and Project objects would have knowledge of their relation (a task is part of a project, etc.), so that when you delete a project, it can delete the tasks that were part of it. The controllers should just be firing off the high-level commands, like telling a project to die. What happens when a project dies is really in the purview of the Project object itself. David