Serializing the search box form is bad, because the AJAX thing submit
any changes that the user makes to the contents of the box. This results
in unexpected behaviour.
See parent commit for the reason we’re doing this.
Currently our AJAX requests only work as `GET` requests. So this commit
does a bit of work to make them work as `POST` requests. This is
optional behaviour, and will only happen when the element in the page
that should be updated with AJAX has the `data-form` attribute set. It
will take the form that has the corresponding `id`, serialise it, and
use that data as the body of the post request. If not form is specified
it will not do the serialisation, and submit as a `GET` request as
before.
Phone numbers and email addresses are showing up in URLs where we let
users search for sent notifications by phone number or email address.
`GET` requests put the form data as a query string in the URL. This is
problematic when people are searching by a recipient’s phone number or
email address, because the URL may show up:
- in our server logs
- in our analytics
- in the user’s browser history
This is bad because these are all places where we don’t want
people’s personal information. It’s not too bad when this is happening
a handful of times. But it would be bad if we kept aggregating this
information because it would allow us to track users across services.
So, while it’s not especially RESTful, it’s better for the search form
to submit as a `POST` request. This way the phone number or email
address goes in the body of the request and does not show up in the URL.
