Use Shoelace Form Components with Hotwire Turbo

README.md

This is a Stimulus controller which will allow a Shoelace Form component to be processed and submitted by Turbo.

Just wrap your <sl-form> control with a form tag:

<%= form_with url: "/test-submit" do %>
  <sl-form data-controller="shoelace-form">
    controls go here
  </sl-form>
<% end %>

This gist includes a Ruby variant and an ES variant, because I wrote the controller using Ruby2JS. You can use the ES variant if you don't have Ruby2JS (it is the direct transpiled output from Ruby2JS).

If you're using Ruby2JS + the Webpack loader, you can just drop the Ruby controller into your project under app/javascript/controllers. Make sure you have the Stimulus autoimport configured in your rb2js.config.rb file:

    def self.options
      {
        eslevel: 2021,
        include: :class,
        underscored_private: true,
        autoimports: {
          [:Controller] => "stimulus",
        }
      }
    end

Also make sure you've updated your Stimulus controller context to load Ruby2JS files in app/javascript/controllers/index.js:

const context = require.context("controllers", true, /_controller\.js(\.rb)?$/)

shoelace_form_controller.js

import { Controller } from "stimulus"

class ShoelaceFormController extends Controller {
  connect() {
    this.element.addEventListener(
      "sl-submit",
      this.submitForm.bind(this)
    );

    this.element.closest("form").addEventListener(
      "turbo:submit-end",
      this.submitEnd.bind(this)
    )
  };

  submitForm(e) {
    let form = this.element.closest("form");
    let submitter = this.element.querySelector("sl-button[submit]");
    if (submitter.disabled) return;
    submitter.loading = true;
    submitter.disabled = true;

    for (let entry of e.detail.formData) {
      let [k, v] = entry;
      let el = document.createElement("input");
      el.type = "hidden";
      el.name = k;
      el.value = v;
      el.deleteMeLater = true;
      form.append(el)
    };

    let el = document.createElement("input");
    el.name = "commit";
    el.type = "submit";
    el.value = submitter.innerHTML;
    el.style.display = "none";
    el.deleteMeLater = true;
    form.append(el);
    el.click()
  };

  submitEnd(e) {
    let submitter = e.target.querySelector("sl-button[submit]");

    if (submitter) {
      submitter.loading = false;
      submitter.disabled = false;
      this.reset(e.target)
    }
  };

  reset(form) {
    form.querySelector("sl-form").getFormControls().then((controls) => {
      for (let control of controls) {
        switch (control.tagName.toLowerCase()) {
        case "sl-checkbox":
        case "sl-radio":
          control.checked = false;
          break;

        default:
          control.value = ""
        }
      }
    });

    for (let control of form.querySelectorAll("input")) {
      if (control.deleteMeLater) control.remove()
    }
  }
};

export default ShoelaceFormController

shoelace_form_controller.js.rb

class ShoelaceFormController < Controller
  def connect()
    self.element.add_event_listener("sl-submit", submit_form.bind(self))
    self.element.closest("form").add_event_listener(
      "turbo:submit-end", submit_end.bind(self)
    )
  end

  def submit_form(e)
    form = self.element.closest("form")
    submitter = self.element.query_selector("sl-button[submit]")

    return if submitter.disabled? # form already submitted, not submitting twice

    submitter.loading = true
    submitter.disabled = true

    e.detail.form_data.each do |entry|
      k, v = entry
      el = document.create_element("input")
      el.type = "hidden"
      el.name = k
      el.value = v
      el.delete_me_later = true
      form.append(el)
    end

    el = document.create_element("input")
    el.name = "commit"
    el.type = "submit"
    el.value = submitter.inner_html
    el.style.display = "none"
    el.delete_me_later = true
    form.append(el)

    el.click()
  end

  def submit_end(e)
    submitter = e.target.query_selector("sl-button[submit]")
    if submitter
      submitter.loading = false
      submitter.disabled = false
      reset(e.target)
    end
  end

  def reset(form)
    form.query_selector("sl-form").get_form_controls().then do |controls|
      controls.each do |control|
        case control.tag_name.downcase()
        when "sl-checkbox", "sl-radio"
          control.checked = false
        else
          control.value = ""
        end
      end
    end

    form.query_selector_all("input").each do |control|
      control.remove() if control.delete_me_later?
    end
  end
end

export default ShoelaceFormController

Typescript version:

import { Controller } from "stimulus"
import SlForm from '@shoelace-style/shoelace/dist/components/form/form'
import SlButton from '@shoelace-style/shoelace/dist/components/button/button'

export default class ShoelaceFormController extends Controller {
  element!: HTMLElement;
  
  connect(): void {
    this.element.addEventListener(
      "sl-submit",
      this.submitForm.bind(this) as EventListener
    )

    this.element?.closest("form")?.addEventListener(
      "turbo:submit-end",
      this.submitEnd.bind(this) as EventListener
    )
  };

  submitForm(e: CustomEvent): void {
    let form = this.element.closest("form");
    if (!form) return;

    let submitter = this.element.querySelector("sl-button[submit]") as SlButton;
    if (submitter.disabled) return;
    submitter.loading = true;
    submitter.disabled = true;

    for (let entry of e.detail.formData) {
      let [k, v] = entry;
      let el = document.createElement("input");
      el.type = "hidden";
      el.name = k;
      el.value = v;
      el.dataset.deleteMeLater = "true";
      form.append(el)
    };

    let el = document.createElement("input");
    el.name = "commit";
    el.type = "submit";
    el.value = submitter.innerHTML;
    el.style.display = "none";
    el.dataset.deleteMeLater = "true";
    form.append(el);
    el.click()
  };

  submitEnd(e: Event): void {
    const target = e.target as SlForm;
    let submitter = target.querySelector("sl-button[submit]") as SlButton;

    if (submitter) {
      submitter.loading = false;
      submitter.disabled = false;
      this.reset(target)
    }
  };

  reset(form: SlForm) {
    const slForm = form.querySelector("sl-form") as SlForm
    const formControls = slForm.getFormControls() as HTMLInputElement[]

    for (let control of formControls) {
      switch (control.tagName.toLowerCase()) {
      case "sl-checkbox":
      case "sl-radio":
        control.checked = false;
        break;

      default:
        control.value = ""
      }
    }

    for (let control of form.querySelectorAll("input")) {
      if (control.dataset.deleteMeLater === "true") control.remove()
    }
  }
};