discourse/app/assets/javascripts/admin/controllers/admin-email-incomings.js.es6

import IncomingEmail from "admin/models/incoming-email";

export default Ember.Controller.extend({
  loading: false,

  actions: {
    loadMore() {
      if (this.get("loading") || this.get("model.allLoaded")) {
        return;
      }
      this.set("loading", true);

      IncomingEmail.findAll(this.get("filter"), this.get("model.length"))
        .then(incoming => {
          if (incoming.length < 50) {
            this.get("model").set("allLoaded", true);
          }
          this.get("model").addObjects(incoming);
        })
        .finally(() => {
          this.set("loading", false);
        });
    }
  }
});