When modal is opened, an ajax request is sent to load the content of the modal
modal opened -> route -> action that contains locals(variables) to be rendered
-> view that is rendered (whether .js or .erb)
place the contents to be rendered in a partial _partial_name.html.erb
If renders .js:
This view should render a partial that contains HTML to be inserted into the modal via $().html(j render partial: '')
Any other routes that want to update the contents of this modal can now render a .js view,
provided all the locals are valid, can also $().html(j render partial: '') the above partial, so as to update the modal