add submitter fields autocomplete

app/javascript/elements/submitter_autocomplete.js

@@ -0,0 +1,56 @@
+import autocomplete from 'autocompleter'
+
+export default class extends HTMLElement {
+  connectedCallback () {
+    autocomplete({
+      input: this.input,
+      preventSubmit: 1,
+      minLength: 1,
+      showOnFocus: true,
+      onSelect: this.onSelect,
+      render: this.render,
+      fetch: this.fetch
+    })
+  }
+
+  onSelect = (item) => {
+    const fields = ['email', 'name', 'phone']
+    const submitterItemEl = this.closest('submitter-item')
+
+    fields.forEach((field) => {
+      const input = submitterItemEl.querySelector(`submitters-autocomplete[data-field="${field}"] input`)
+
+      if (input && item[field]) {
+        input.value = item[field]
+      }
+    })
+  }
+
+  fetch = (text, resolve) => {
+    if (text) {
+      const queryParams = new URLSearchParams({ q: text, field: this.dataset.field })
+
+      fetch('/api/submitters_autocomplete?' + queryParams).then(async (resp) => {
+        const items = await resp.json()
+
+        resolve(items)
+      }).catch(() => {
+        resolve([])
+      })
+    } else {
+      resolve([])
+    }
+  }
+
+  render = (item) => {
+    const div = document.createElement('div')
+
+    div.textContent = item[this.dataset.field]
+
+    return div
+  }
+
+  get input () {
+    return this.querySelector('input')
+  }
+}