Simple explanation with example of how to show error message with html_safe

[thebravoman]

I would like to show an error message with a link to a guide that explains why this error occurs and what you could do about it. It also must have a link to another resource in the app. It is practically around "this resource is locked because it is also used in that resource '

I am sure that I could spend the time to figure out how to do it, but internet searches for me are useless and LLMs are suggesting all kind of things that do not work with 5.4.0.
I am sure simple_form has figured this out. I understand that these error messages should not be html safe by default because XSS.

What I think would be helpful is for the README to give such an example and to reduce the confusion

I would love to write one on my own, but I have no idea how this is done and what is simple_form idea for doing this.

[carlosantoniodasilva]

You can just mark the error message as html_safe, and simple form should render that correctly:

  validates_format_of :name, with: /foo/, message: "<a href='/'>foo</a> error".html_safe

If you interpolate user entered values, you should make sure to html escape them yourself.

Note that this doesn't work with I18n translations automatically, you'd have to fetch the error yourself and mark it as html safe I believe.

[thebravoman]

And this is the point of the pr. The .html_safe is not in the guide, you are also not sure about how to do it with i18n, we could figure it out, but it is confusing. The "put _html to the key" response from LLMs does not work and there is no good way to see how it is done from the guide.

My error specifically are in the i18n yml.

LLMs and internet searches are suggesting to do

<% @record.errors[:campaign_id].each do |msg| %>
    <div class="invalid-feedback d-block"><%= msg.html_safe %></div>
  <% end %>

below the field, but this is not right as simple form is already doing something similar, so you have to call error: false and from there maintain the errors yourself.

Probably if you could pass error: false you could also pass error: :html.

Point it is that we are left guessing from the guide
@carlosantoniodasilva

[carlosantoniodasilva]

The best I can do is document it a bit better, and make sure SF is doing the right thing when given html_safe errors: #1864

I don't think I want to support any error: :html option, because error translation is a Rails / ActiveModel concern, not a SimpleForm one.