Some institutions using CONSUL have expressed interest in this feature
since some of their tenants might already have their own domains.
We've considered many options for the user interface to select whether
we're using a subdomain or a domain, like having two separate fields,
using a check box, ... In the end we've chosen radio buttons because
they make it easier to follow a logical sequence: first you decide
whether you're introducing a domain or subdomain, and then you enter it.
We've also considered hiding this option and assuming "if it's got a
dot, it's a domain". However, this wouldn't work with nested subdomains
and it wouldn't work with domains which are simply machine names.
Note that a group of radio buttons (or check boxes) is difficult to
style when the text of the label might expand over more than one line
(as is the case here on small screens); in this case, most solutions
result in the second line of the label appearing immediately under the
radio button, instead of being aligned with the first line of the label.
That's why I've added a container for the input+label combination.
Sometimes it might be convenient to use completely different views for
different tenants. For example, a certain tenant might use a footer that
has nothing to do with the default one.
For these cases, instead of adding `case Tenant.current_schema`
conditions to the view, it might be tidier to use a different file.
For this purpose, we're using Rails variants [1], which means that a
tenant named `mytenant` will use a template ending with
`.html+mytenant.erb` if it's available.
This works with components too, but has a limitation: when using the
`custom/` folder to add ERB files for a tenant, the default tenant ERB
file needs to be added to the `custom/` folder as well; if there aren't
changes to this file, a symbolic link will do.
For example, if we're writing a custom `admin/action_component` view for
the tenant `milky-way` but don't need to change this file for the
default tenant:
1. Create `app/components/custom/admin/action_component.rb` according to
the components customizations documentation [2]
2. Create the custom view for the `milky-way` tenant and save it under
`app/components/custom/admin/action_component.html+milky-way.erb`
3. Enter the `app/components/custom/admin/` folder and run `ln -s
../../admin/action_component.html.erb`
We're also adding some controller tests. Since Rails doesn't load the
middleware during controller tests, we're stubbing the `current_schema`
method directly instead of changing the subdomain of the request.
[1] https://guides.rubyonrails.org/v6.0/layouts_and_rendering.html#the-variants-option
[2] https://docs.consulproject.org/docs/english-documentation/customization/components
