index.js

import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';
import { A } from '@ember/array';
import { action } from '@ember/object';


export default class CommanderComponent extends Component {
  /*
    Arguments:

    @node = current node/folder
    @extranode = extract node to display (on second panel)
    @hint = "left" | "right" indicates which of two sides
    is current panel displayed. @hint is "left" indicates that
    commander is displayed in left panel.
  */
  // show create new folder modal dialog?
  @tracked show_new_folder_modal = false;

  // show rename node modal dialog?
  @tracked show_rename_node_modal = false;

  @tracked show_confirm_deletion_modal = false;

  // nodes are displayed as list or as grid?
  @tracked view_mode = 'list';

  @tracked selected_nodes = A([]);

  // new records created via New Folder or Upload Documents
  @tracked new_records = A([]);
  @tracked __new_record; // used as workaround for an ember bug

  @tracked deleted_records = A([]);
  @tracked __deleted_records; // used as workaround for an ember bug

  @action
  openNewFolderModal() {
    this.show_new_folder_modal = true;
  }

  @action
  closeNewFolderModal(new_record) {
    this.new_records.push(new_record);
    this.__new_record = new_record; // workaround of ember bug
    this.show_new_folder_modal = false;
  }

  @action
  openRenameModal() {
    this.show_rename_node_modal = true;
  }

  @action
  closeRenameModal() {
    this.show_rename_node_modal = false;
    this.selected_nodes = A([]);
  }

  @action
  openConfirmDeletionModal() {
    this.show_confirm_deletion_modal = true;
  }

  @action
  closeConfirmDeletionModal(deleted_records) {
    this.show_confirm_deletion_modal = false;
    this.selected_nodes = A([]);
    this.deleted_records = this.deleted_records.concat(deleted_records);
    this.__deleted_records = deleted_records;
  }

  @action
  onViewModeChange(new_view_mode) {
    this.view_mode = new_view_mode;
  }

  @action
  onCheckboxChange({node, is_selected}) {
    /**
    Triggered whenever node's checkbox changes.

    `node` is an instance of Node model of whose
    selection state changed.

    `is_selected` - new selection state i.e. if user checked
    the checkbox then `is_selected` is true; if user unchecked
    the checkbox  then `is_selected` is false;
    */
    if (is_selected) {
      this.selected_nodes.pushObject(node);
    } else {
      this.selected_nodes.removeObject(node);
    }
  }

  get children() {
    /**
      Update children nodes (e.g. with newly added records) for better UX

      In order to provide better user experiece, when user creates new folders,
      uploads documents, deletes nodes (folder or documents) etc commander will
      show immediate effect of the action: newly created folder must be seen on
      same page as currenly user is in; even if we fetch again children, newly
      folder might not be visible to the user, as according to
      sorting/pagination creteria it(newly created folder) may not reside in
      current page.

      This is where current method comes handy - sticking with above example of
      newly created folder - this method will add newly created folder to the
      list of already existing children to make it visible to the user.
     */
    let children_copy = A(this.args.children);

    if (this.new_records.length > 0) {
      while(this.new_records.length > 0) {
        children_copy.unshift(
          this.new_records.pop()
        );
      }
    }

    if (this.deleted_records.length > 0) {
      children_copy = children_copy.filter(
        item => !this.deleted_records.includes(item)
      );
    }

    if (this.__new_record) { // workaround ember bug
      // Ember bug! Without this empty statement
      // updates on tracked attributes ``this.new_records``
      // will not trigger template updates i.e. ``this.children``
      //
      // pass
    }

    if (this.__deleted_records) {
      // similar to ``this.__new_record`` - it is used
      // here to help ember with tracking of ``this.deleted_records`` array
    }
    return children_copy;
  }
}