discourse/app/assets/javascripts/admin/controllers/admin-customize-email-templates-edit.js

import I18n from "I18n";
import discourseComputed from "discourse-common/utils/decorators";
import Controller from "@ember/controller";
import { popupAjaxError } from "discourse/lib/ajax-error";
import { bufferedProperty } from "discourse/mixins/buffered-content";

export default Controller.extend(bufferedProperty("emailTemplate"), {
  saved: false,

  @discourseComputed("buffered.body", "buffered.subject")
  saveDisabled(body, subject) {
    return (
      this.emailTemplate.body === body && this.emailTemplate.subject === subject
    );
  },

  @discourseComputed("buffered")
  hasMultipleSubjects(buffered) {
    if (buffered.getProperties("subject")["subject"]) {
      return false;
    } else {
      return buffered.getProperties("id")["id"];
    }
  },

  actions: {
    saveChanges() {
      this.set("saved", false);
      const buffered = this.buffered;
      this.emailTemplate
        .save(buffered.getProperties("subject", "body"))
        .then(() => {
          this.set("saved", true);
        })
        .catch(popupAjaxError);
    },

    revertChanges() {
      this.set("saved", false);
      bootbox.confirm(
        I18n.t("admin.customize.email_templates.revert_confirm"),
        result => {
          if (result) {
            this.emailTemplate
              .revert()
              .then(props => {
                const buffered = this.buffered;
                buffered.setProperties(props);
                this.commitBuffer();
              })
              .catch(popupAjaxError);
          }
        }
      );
    }
  }
});