1 files changed, 37 insertions, 0 deletions
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js
index 36a428d966..1311105572 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js
@@ -662,6 +662,43 @@
     }
   };
 
+  // TODO(taoalpha): List all internal supported event names.
+  // Also convert this to inherited class once we move Gerrit to class.
+  Gerrit._eventEmitter = new EventEmitter();
+  ['addListener',
+    'dispatch',
+    'emit',
+    'off',
+    'on',
+    'once',
+    'removeAllListeners',
+    'removeListener',
+  ].forEach(method => {
+    /**
+     * Enabling EventEmitter interface on Gerrit.
+     *
+     * This will enable to signal across different parts of js code without relying on DOM,
+     * including core to core, plugin to plugin and also core to plugin.
+     *
+     * @example
+     *
+     * // Emit this event from pluginA
+     * Gerrit.install(pluginA => {
+     *   fetch("some-api").then(() => {
+     *     Gerrit.on("your-special-event", {plugin: pluginA});
+     *   });
+     * });
+     *
+     * // Listen on your-special-event from pluignB
+     * Gerrit.install(pluginB => {
+     *   Gerrit.on("your-special-event", ({plugin}) => {
+     *     // do something, plugin is pluginA
+     *   });
+     * });
+     */
+    Gerrit[method] = Gerrit._eventEmitter[method].bind(Gerrit._eventEmitter);
+  });
+
   window.Gerrit = Gerrit;
 
   // Preloaded plugins should be installed after Gerrit.install() is set,