client/components/tinymce/plugins/embed/plugin.js
function embed( editor ) {
	let embedDialogContainer;

	/**
	 * Open or close the EmbedDialog
	 *
	 * @param {boolean} visible `true` makes the dialog visible; `false` hides it.
	 */
	const render = ( visible = true ) => {
		const selectedEmbedNode = editor.selection.getNode();
		const store = editor.getParam( 'redux_store' );
		const embedDialogProps = {
			embedUrl: selectedEmbedNode.innerText || selectedEmbedNode.textContent,
			isVisible: visible,
			onCancel: () => render( false ),
			onUpdate: newUrl => {
				editor.execCommand( 'mceInsertContent', false, newUrl );
				render( false );
			},
		};

		renderWithReduxStore(
			React.createElement( EmbedDialog, embedDialogProps ),
			embedDialogContainer,
			store
		);

		// Focus on the editor when closing the dialog, so that the user can start typing right away
		// instead of having to tab back to the editor.
		if ( ! visible ) {
			editor.focus();
		}
	};

	editor.addCommand( 'embedDialog', () => render() );

	editor.on( 'init', () => {
		embedDialogContainer = editor.getContainer().appendChild( document.createElement( 'div' ) );
	} );

	editor.on( 'remove', () => {
		ReactDom.unmountComponentAtNode( embedDialogContainer );
		embedDialogContainer.parentNode.removeChild( embedDialogContainer );
		embedDialogContainer = null;
	} );
}
function embed( editor ) {
	let embedDialogContainer;

	/**
	 * Open or close the EmbedDialog
	 *
	 * @param {boolean} visible `true` makes the dialog visible; `false` hides it.
	 */
	const render = ( visible = true ) => {
		const selectedEmbedNode = editor.selection.getNode();
		const store = editor.getParam( 'redux_store' );
		const embedDialogProps = {
			embedUrl: selectedEmbedNode.innerText || selectedEmbedNode.textContent,
			isVisible: visible,
			onCancel: () => render( false ),
			onUpdate: newUrl => {
				editor.execCommand( 'mceInsertContent', false, newUrl );
				render( false );
			},
		};

		renderWithReduxStore(
			React.createElement( EmbedDialog, embedDialogProps ),
			embedDialogContainer,
			store
		);

		// Focus on the editor when closing the dialog, so that the user can start typing right away
		// instead of having to tab back to the editor.
		if ( ! visible ) {
			editor.focus();
		}
	};

	editor.addCommand( 'embedDialog', () => render() );

	editor.on( 'init', () => {
		embedDialogContainer = editor.getContainer().appendChild( document.createElement( 'div' ) );
	} );

	editor.on( 'remove', () => {
		ReactDom.unmountComponentAtNode( embedDialogContainer );
		embedDialogContainer.parentNode.removeChild( embedDialogContainer );
		embedDialogContainer = null;
	} );
}
Manages an EmbedDialog to allow editing the URL of an embed inside the editor.

@param {object} editor An instance of TinyMCE