Add bridge form controller.

app/javascript/bridge/controllers/bridge/form_controller.js

@@ -0,0 +1,49 @@
+import { BridgeComponent } from "@hotwired/hotwire-native-bridge"
+import { BridgeElement } from "@hotwired/hotwire-native-bridge"
+
+export default class extends BridgeComponent {
+  static component = "form"
+  static targets = [ "submit" ]
+  static values = { submitTitle: String }
+
+  connect() {
+    super.connect()
+    if (!this.hasSubmitTarget) return
+    this.notifyBridgeOfConnect()
+    this.observeSubmitTarget()
+  }
+
+  disconnect() {
+    super.disconnect()
+    this.submitObserver?.disconnect()
+  }
+
+  notifyBridgeOfConnect() {
+    const submitButton = new BridgeElement(this.submitTarget)
+    const title = submitButton.title
+    const displaysNavButtonMenu = submitButton.displaysNavButtonMenu()
+
+    this.send("connect", { title, displaysNavButtonMenu }, () => {
+      this.submitTarget.click()
+    })
+  }
+
+  observeSubmitTarget() {
+    this.submitObserver = new MutationObserver(() => {
+      this.send(this.submitTarget.disabled ? "submitDisabled" : "submitEnabled")
+    })
+
+    this.submitObserver.observe(this.submitTarget, {
+      attributes: true,
+      attributeFilter: [ "disabled" ]
+    })
+  }
+
+  submitStart() {
+    this.send("submitStart")
+  }
+
+  submitEnd() {
+    this.send("submitEnd")
+  }
+}

app/javascript/bridge/initializers/bridge_element.js

@@ -43,3 +43,7 @@ BridgeElement.prototype.getOrder = function() {
 BridgeElement.prototype.shouldDisplayAsFormSubmitMenu = function() {
   return this.bridgeAttribute("display-as-form-submit-menu") === "true"
 }
+
+BridgeElement.prototype.displaysNavButtonMenu = function() {
+  return this.bridgeAttribute("displays-nav-button-menu") === "true"
+}