My Stimulus checkbox script in Rails 7 doesn't work - ruby-on-rails

Question

I'm learning stimulus and trying to get add a checkbox feature where you can mark an order as complete from the show page without using a form. I followed this tutorial, but am not getting the correct results. The checkbox does nothing when clicked and unchecks when refreshed; however if I manually set the complete attribute to true, the checkbox is automatically checked when loading the page, as it should.
I have a model "Order" with a boolean attribute "complete". Here's my show.html.erb section
<tr data-controller="todo" data-todo-update-url="<%= order_path(#order.id) %>">
<td>
<div>
<input type="checkbox"
data-action="todo#toggle"
data-target="todo.completed"
<% if #order.complete %> checked <% end %> >
</div>
</td>
</tr>
Here's my stimulus todo_controller
import { Controller } from "#hotwired/stimulus"
export default class extends Controller {
static targets = [ "completed" ]
toggle(event) {
// Inside the toggle(event) function, let’s start by getting the value of the checkbox,
// and put it into a FormData object
let formData = new FormData()
formData.append("#order[complete]", this.completedTarget.completed);
// Let’s post that data to the "update-url" value we set on the Todo row.
// We’ll set the method to PATCH so that it gets routed to our todo#update on our controller.
// The credentials and headers included ensure we send the session cookie and the CSRF protection token and
// and prevent an ActionController::InvalidAuthenticityToken error.
fetch(this.data.get("update-url"), {
body: formData,
method: 'PATCH',
dataType: 'script',
credentials: "include",
headers: {
"X-CSRF-Token": getMetaValue("csrf-token")
}
})
// We can take the Response object and verify that our request was successful.
// If there was an error, we’ll revert the checkbox change.
.then(function(response) {
if (response.status != 204) {
event.target.complete = !event.target.complete
}
})
}
}
Can someone tell me where my code is going wrong?

Answer 1

This is more a long comment than a solution but few things I see :
You create an empty form and append a single input with name
"#order[complete]" though your Stimulus controller is Javascript
and has no knowledge of # the such way you use in Ruby. Also params
names are usually model[field] then I think you don't need the #.
"order[complete]" should be fine.
Also you grab the value from a specific target for the aforementionned value with this.completedTarget.completed. Should you not rather pick the value of the input field ? and rather grab this.completedTarget.value or maybe the checked status this.completedTarget.checked
You are getting the URL to your fetch from a data attribute. I am not a stimulus expert but it doesn't look like anything Stimulus related. As of now you have written it this.data.get("update-url") but in regular javascript, something like this.element.dataset.todoUpdateUrl should work.
And just to be sure there is no confusion to about where you will
call this , just declare it at the top of your Stimulus methd like
this : var backUrl = this.element.dataset.todoUpdateUrl. And fill the url to your fetch as just fetch(backUrl,...
you pass the formData directly to your fetch body. If this doesn't work, try to stringify it and extract the entries like : JSON.stringify(Object.fromEntries(formData)). Also I am not too sure about the dataType: 'script', you may just omit that alltogether.
There may be other problems that I don't see. Also when you are dealing with JS, don't only look to your Rails console, especially if nothing hits the backend. Open the developper / inspect tool in your browser and monitor the console there, you should see all the XHR (async) requests made to your app.
If nothing happens, then your fetch is not firing and there need to be more investigations made..