discourse/app/assets/javascripts/discourse/components/avatar-uploader.js.es6

import computed from "ember-addons/ember-computed-decorators";
import UploadMixin from "discourse/mixins/upload";

export default Em.Component.extend(UploadMixin, {
  type: "avatar",
  tagName: "span",
  imageIsNotASquare: false,

  @computed("uploading")
  uploadButtonText(uploading) {
    return uploading ? I18n.t("uploading") : I18n.t("user.change_avatar.upload_picture");
  },

  validateUploadedFilesOptions() {
    return { imagesOnly: true };
  },

  uploadDone(upload) {
    this.setProperties({
      imageIsNotASquare: upload.width !== upload.height,
      uploadedAvatarTemplate: upload.url,
      uploadedAvatarId: upload.id,
    });

    this.sendAction("done");
  },

  @computed("user_id")
  data(user_id) {
    return { user_id };
  }
});