discourse/app/assets/javascripts/admin/controllers/admin-email-logs.js

import Controller from "@ember/controller";
import EmailLog from "admin/models/email-log";

export default Controller.extend({
  loading: false,

  loadLogs(sourceModel, loadMore) {
    if ((loadMore && this.loading) || this.get("model.allLoaded")) {
      return;
    }

    this.set("loading", true);

    sourceModel = sourceModel || EmailLog;

    return sourceModel
      .findAll(this.filter, loadMore ? this.get("model.length") : null)
      .then(logs => {
        if (this.model && loadMore && logs.length < 50) {
          this.model.set("allLoaded", true);
        }

        if (this.model && loadMore) {
          this.model.addObjects(logs);
        } else {
          this.set("model", logs);
        }
      })
      .finally(() => this.set("loading", false));
  },

  actions: {
    loadMore() {
      this.loadLogs(EmailLog, true);
    }
  }
});