rasa: add support for eventhook which provides user and bot messages in realtime and supports redirecting to a new app

lib/tasks/task.js

@@ -99,6 +99,25 @@ class Task extends Emitter {
     }
   }
 
+  async performHook(cs, hook, results) {
+    const json = await cs.requestor.request(hook, results);
+    if (json && Array.isArray(json)) {
+      const makeTask = require('./make_task');
+      const tasks = normalizeJambones(this.logger, json).map((tdata) => makeTask(this.logger, tdata));
+      if (tasks && tasks.length > 0) {
+        this.redirect(cs, tasks);
+        return true;
+      }
+    }
+    return false;
+  }
+
+  redirect(cs, tasks) {
+    this.logger.info({tasks: tasks}, `${this.name} replacing application with ${tasks.length} tasks`);
+    this.isReplacingApplication = true;
+    cs.replaceApplication(tasks);
+  }
+
   async transferCallToFeatureServer(cs, sipAddress, opts) {
     const uuid = uuidv4();
     const {addKey} = cs.srf.locals.dbHelpers;