Links acting like buttons have a few disadvantages.
First, screen readers will announce them as "links". Screen reader users
usually associate links with "things that get you somewhere" and buttons
with "things that perform an action". So when something like "Delete,
link" is announced, they'll probably think this is a link which will
take them to another page where they can delete a record.
Furthermore, the URL of the link for the "destroy" action might be the
same as the URL for the "show" action (only one is accessed with a
DELETE request and the other one with a GET request). That means screen
readers could announce the link like "Delete, visited link", which is
very confusing.
They also won't work when opening links in a new tab, since opening
links in a new tab always results in a GET request to the URL the link
points to.
Finally, submit buttons work without JavaScript enabled, so they'll work
even if the JavaScript in the page hasn't loaded (for whatever reason).
For all these reasons (and probably many more), using a button to send
forms is IMHO superior to using links.
There's one disadvantage, though. Using `button_to` we create a <form>
tag, which means we'll generate invalid HTML if the table is inside
another form. If we run into this issue, we need to use `button_tag`
with a `form` attribute and then generate a form somewhere else inside
the HTML (with `content_for`).
Note we're using `button_to` with a block so it generates a <button>
tag. Using it in a different way the text would result in an <input />
tag, and input elements can't have pseudocontent added via CSS.
The following code could be a starting point to use the `button_tag`
with a `form` attribute. One advantage of this approach is screen
readers wouldn't announce "leaving form" while navigating through these
buttons. However, it doesn't work in Internet Explorer.
```
ERB:
<% content_for(:hidden_content, form_tag(path, form_options) {}) %>
<%= button_tag text, button_options %>
Ruby:
def form_id
path.gsub("/", "_")
end
def form_options
{ id: form_id, method: options[:method] }
end
def button_options
html_options.except(:method).merge(form: form_id)
end
Layout:
<%= content_for :hidden_content %> # Right before the `</body>`
```
Currently it is not necessary to include the link_url field.
When we display these cards without link_url, they create an empty link that
redirects to the same page. I understand that this is not a desired behavior, so I
think it is better to add a validation in this case and force administrators to add a
link_url when creating a card.
JavaScript is used by about 98% of web users, so by testing without it
enabled, we're only testing that the application works for a very
reduced number of users.
We proceeded this way in the past because CONSUL started using Rails 4.2
and truncating the database between JavaScript tests with database
cleaner, which made these tests terribly slow.
When we upgraded to Rails 5.1 and introduced system tests, we started
using database transactions in JavaScript tests, making these tests much
faster. So now we can use JavaScript tests everywhere without critically
slowing down our test suite.
These cards will be displayed in the SDG homepage.
Note there seems to be a strange behavior in cancancan. If we define
these rules:
can :manage, Widget::Card, page_type: "SDG::Phase"
can :manage, Widget::Card
The expected behavior is the first rule will always be ignored because
the second one overwrites it. However, when creating a new card with
`load_and_authorize_resource` will automatically add `page_type:
"SDG::Phase"`.
Similarly, if we do something like:
can :manage, Widget::Card, id: 3
can :manage, Widget::Card
Then the new card will have `3` as an ID.
Maybe upgrading cancancan solves the issue; we haven't tried it. For now
we're defining a different rule when creating widget cards.
