Method initComponent

src/core/a-entity.js:273–315

* Initialize component. * * @param {string} attrName - Attribute name associated to the component. * @param {object} data - Component data * @param {boolean} isDependency - True if the component is a dependency.

(attrName, data, isDependency)

   * @param {boolean} isDependency - True if the component is a dependency.
   */
  initComponent (attrName, data, isDependency) {
    var component;
    var componentId;
    var componentInfo;
    var componentName;
    var isComponentDefined;

    componentInfo = utils.split(attrName, MULTIPLE_COMPONENT_DELIMITER);
    componentName = componentInfo[0];
    componentId = componentInfo.length > 2
      ? componentInfo.slice(1).join('__')
      : componentInfo[1];

    // Not a registered component.
    if (!COMPONENTS[componentName]) { return; }

    // Component is not a dependency and is undefined.
    // If a component is a dependency, then it is okay to have no data.
    isComponentDefined = checkComponentDefined(this, attrName) ||
                         data !== undefined;
    if (!isComponentDefined && !isDependency) { return; }

    // Component already initialized.
    if (attrName in this.components) { return; }

    // Initialize dependencies first
    this.initComponentDependencies(componentName);

    // Initialize component
    component = new COMPONENTS[componentName].Component(this, data, componentId);
    if (this.isPlaying) { component.play(); }

    // Components are reflected in the DOM as attributes but the state is not shown
    // hence we set the attribute to empty string.
    // The flag justInitialized is for attributeChangedCallback to not overwrite
    // the component with the empty string.
    if (!this.hasAttribute(attrName)) {
      component.justInitialized = true;
      window.HTMLElement.prototype.setAttribute.call(this, attrName, '');
    }

    debug('Component initialized: %s', attrName);
  }

  /**
   * Initialize dependencies of a component.