src/view/containerelement.js
/**
* @license Copyright (c) 2003-2020, CKSource - Frederico Knabben. All rights reserved.
* For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
*/
/**
* @module engine/view/containerelement
*/
import Element from './element';
/**
* Containers are elements which define document structure. They define boundaries for
* {@link module:engine/view/attributeelement~AttributeElement attributes}. They are mostly used for block elements like `<p>` or `<div>`.
*
* Editing engine does not define a fixed HTML DTD. This is why a feature developer needs to choose between various
* types (container element, {@link module:engine/view/attributeelement~AttributeElement attribute element},
* {@link module:engine/view/emptyelement~EmptyElement empty element}, etc) when developing a feature.
*
* The container element should be your default choice when writing a converter, unless:
*
* * this element represents a model text attribute (then use {@link module:engine/view/attributeelement~AttributeElement}),
* * this is an empty element like `<img>` (then use {@link module:engine/view/emptyelement~EmptyElement}),
* * this is a root element,
* * this is a nested editable element (then use {@link module:engine/view/editableelement~EditableElement}).
*
* To create a new container element instance use the
* {@link module:engine/view/downcastwriter~DowncastWriter#createContainerElement `DowncastWriter#createContainerElement()`}
* method.
*
* @extends module:engine/view/element~Element
*/
export default class ContainerElement extends Element {
/**
* Creates a container element.
*
* @see module:engine/view/downcastwriter~DowncastWriter#createContainerElement
* @see module:engine/view/element~Element
* @protected
* @param {module:engine/view/document~Document} document The document instance to which this element belongs.
* @param {String} name Node name.
* @param {Object|Iterable} [attrs] Collection of attributes.
* @param {module:engine/view/node~Node|Iterable.<module:engine/view/node~Node>} [children]
* A list of nodes to be inserted into created element.
*/
constructor( document, name, attrs, children ) {
super( document, name, attrs, children );
/**
* Returns block {@link module:engine/view/filler filler} offset or `null` if block filler is not needed.
*
* @method #getFillerOffset
* @returns {Number|null} Block filler offset or `null` if block filler is not needed.
*/
this.getFillerOffset = getFillerOffset;
}
/**
* Checks whether this object is of the given.
*
* containerElement.is( 'containerElement' ); // -> true
* containerElement.is( 'element' ); // -> true
* containerElement.is( 'node' ); // -> true
* containerElement.is( 'view:containerElement' ); // -> true
* containerElement.is( 'view:element' ); // -> true
* containerElement.is( 'view:node' ); // -> true
*
* containerElement.is( 'model:element' ); // -> false
* containerElement.is( 'documentFragment' ); // -> false
*
* Assuming that the object being checked is a container element, you can also check its
* {@link module:engine/view/containerelement~ContainerElement#name name}:
*
* containerElement.is( 'div' ); // -> true if this is a div container element
* containerElement.is( 'contaienrElement', 'div' ); // -> same as above
* text.is( 'div' ); -> false
*
* {@link module:engine/view/node~Node#is Check the entire list of view objects} which implement the `is()` method.
*
* @param {String} type Type to check when `name` parameter is present.
* Otherwise, it acts like the `name` parameter.
* @param {String} [name] Element name.
* @returns {Boolean}
*/
is( type, name = null ) {
if ( !name ) {
return type === 'containerElement' || type === 'view:containerElement' ||
// From super.is(). This is highly utilised method and cannot call super. See ckeditor/ckeditor5#6529.
type === this.name || type === 'view:' + this.name ||
type === 'element' || type === 'view:element' ||
type === 'node' || type === 'view:node';
} else {
return name === this.name && (
type === 'containerElement' || type === 'view:containerElement' ||
// From super.is(). This is highly utilised method and cannot call super. See ckeditor/ckeditor5#6529.
type === 'element' || type === 'view:element'
);
}
}
}
/**
* Returns block {@link module:engine/view/filler filler} offset or `null` if block filler is not needed.
*
* @returns {Number|null} Block filler offset or `null` if block filler is not needed.
*/
export function getFillerOffset() {
const children = [ ...this.getChildren() ];
const lastChild = children[ this.childCount - 1 ];
// Block filler is required after a `<br>` if it's the last element in its container. See #1422.
if ( lastChild && lastChild.is( 'element', 'br' ) ) {
return this.childCount;
}
for ( const child of children ) {
// If there's any non-UI element – don't render the bogus.
if ( !child.is( 'uiElement' ) ) {
return null;
}
}
// If there are only UI elements – render the bogus at the end of the element.
return this.childCount;
}