Written May 12, 2015. Tagged Ruby on Rails.
When you reuse something, like a Ruby on Rails partial or i18n translation string, it's tempting to just reference it by its current name.
admin/customers/show.html.erb renders the
admin/customers/_invoices.html.erb partial, and now you want to render it from
superadmin/customers/show.html.erb as well.
Or maybe you use
t("customers.show.title") to output a translation string in the
customers/show.html.erb template, and now you want to reuse it in a customer widget elsewhere.
If you don't rename the partial or the translation key, the name will be left incorrectly suggesting it's related to just that one controller, or just that one template.
Now every future change is in jeopardy of this reasonable misunderstanding. Someone intends to change a page title but also accidentally changes the widget. They don't necessarily have the same reason to change.
Instead, you can make the sharing explicit.
You could move the partial to
shared/customers/_invoices.html.erb, and the translation key to
Now if you change any of these values, you will expect them to have a wider effect.
I think of this a bit like private methods: being private suggests only being used in the same file. Being public suggests a wider scope.
As always, there are nuances and trade-offs. Using
customers.show.title in a link to that page could make sense, for example, since we specifically want to reference the page title.