add shared link form fields preferences

app/javascript/application.js

@@ -35,6 +35,7 @@ import SetDateButton from './elements/set_date_button'
 import IndeterminateCheckbox from './elements/indeterminate_checkbox'
 import AppTour from './elements/app_tour'
 import DashboardDropzone from './elements/dashboard_dropzone'
+import RequiredCheckboxGroup from './elements/required_checkbox_group'
 
 import * as TurboInstantClick from './lib/turbo_instant_click'
 
@@ -105,6 +106,7 @@ safeRegisterElement('indeterminate-checkbox', IndeterminateCheckbox)
 safeRegisterElement('app-tour', AppTour)
 safeRegisterElement('dashboard-dropzone', DashboardDropzone)
 safeRegisterElement('check-on-click', CheckOnClick)
+safeRegisterElement('required-checkbox-group', RequiredCheckboxGroup)
 
 safeRegisterElement('template-builder', class extends HTMLElement {
   connectedCallback () {

app/javascript/elements/required_checkbox_group.js

@@ -0,0 +1,17 @@
+export default class extends HTMLElement {
+  connectedCallback () {
+    this.querySelectorAll('input[type="checkbox"]').forEach(checkbox => {
+      checkbox.addEventListener('change', this.handleChange)
+    })
+  }
+
+  handleChange = () => {
+    if (this.checkedCount !== 0) {
+      this.closest('form')?.requestSubmit()
+    }
+  }
+
+  get checkedCount () {
+    return this.querySelectorAll('input[type="checkbox"]:checked').length
+  }
+}