add csp

app/javascript/elements/show_on_value.js

@@ -0,0 +1,17 @@
+export default class extends HTMLElement {
+  connectedCallback () {
+    this.addEventListener('change', (event) => {
+      const targetValue = this.dataset.value
+      const selectorId = this.dataset.selectorId
+      const targetElement = document.getElementById(selectorId)
+
+      if (event.target.value === targetValue) {
+        targetElement.classList.remove('hidden')
+      } else {
+        targetElement.classList.add('hidden')
+        targetElement.value = ''
+        event.target.form.requestSubmit()
+      }
+    })
+  }
+}