mediawiki-extensions-Visual.../modules/ve/ce/ve.ce.ContentBranchNode.js
Inez Korczyński 93357b8f34 Performance improvement for getRenderedContents
Instead of calling $.append for every single char - buffer and call $.append only when really needed.

Change-Id: I53acfa795ea5dc6a8ca39ce11017daa85c9151d2
2013-04-25 14:15:01 -07:00

167 lines
4.4 KiB
JavaScript

/*!
* VisualEditor ContentEditable ContentBranchNode class.
*
* @copyright 2011-2013 VisualEditor Team and others; see AUTHORS.txt
* @license The MIT License (MIT); see LICENSE.txt
*/
/**
* ContentEditable content branch node.
*
* Content branch nodes can only have content nodes as children.
*
* @abstract
* @extends ve.ce.BranchNode
* @constructor
* @param {ve.dm.BranchNode} model Model to observe
* @param {jQuery} [$element] Element to use as a container
*/
ve.ce.ContentBranchNode = function VeCeContentBranchNode( model, $element ) {
// Parent constructor
ve.ce.BranchNode.call( this, model, $element );
// Properties
var lastTransaction;
// Events
// Main purpose of code below is to increase performance by ensuring that renderContents() is
// called exactly once after transaction is processed. Case when childUpdate event is received
// multiple times is for instance when entire paragraph with multiple nodes inside it
// (e.g. <p>123<alien></alien>456</p>) is being annotated.
// Keeping reference to transaction object in view may look like anti pattern - however please
// have in mind that this transaction here is not being used in any other way than just as
// a flag to figure out if renderContents should be executed or not.
this.on( 'childUpdate', ve.bind( function( transaction ) {
if ( transaction instanceof ve.dm.Transaction ) {
if ( lastTransaction === transaction ) {
return;
}
lastTransaction = transaction;
}
this.renderContents();
}, this ) );
// Initialization
this.renderContents();
};
/* Inheritance */
ve.inheritClass( ve.ce.ContentBranchNode, ve.ce.BranchNode );
/* Methods */
/**
* Handle splice events.
*
* This is used to automatically render contents.
* @see ve.ce.BranchNode#onSplice
*
* @method
*/
ve.ce.ContentBranchNode.prototype.onSplice = function () {
// Call parent implementation
ve.ce.BranchNode.prototype.onSplice.apply( this, arguments );
// Rerender to make sure annotations are applied correctly
this.renderContents();
};
/**
* Get an HTML rendering of the contents.
*
* @method
* @returns {jQuery}
*/
ve.ce.ContentBranchNode.prototype.getRenderedContents = function () {
var i, itemHtml, itemAnnotations, $ann,
store = this.model.doc.getStore(),
annotationStack = new ve.dm.AnnotationSet( store ),
annotatedHtml = [],
$wrapper = $( '<div>' ),
$current = $wrapper,
buffer = '';
function flushBuffer() {
if ( buffer !== '' ) {
$current.append( buffer );
buffer = '';
}
}
function openAnnotation( annotation ) {
flushBuffer();
// Create a new DOM node and descend into it
$ann = ve.ce.annotationFactory.create( annotation.getType(), annotation ).$;
$current.append( $ann );
$current = $ann;
}
function closeAnnotation() {
flushBuffer();
// Traverse up
$current = $current.parent();
}
// Gather annotated HTML from the child nodes
for ( i = 0; i < this.children.length; i++ ) {
annotatedHtml = annotatedHtml.concat( this.children[i].getAnnotatedHtml() );
}
// Render HTML with annotations
for ( i = 0; i < annotatedHtml.length; i++ ) {
if ( ve.isArray( annotatedHtml[i] ) ) {
itemHtml = annotatedHtml[i][0];
itemAnnotations = new ve.dm.AnnotationSet( store, annotatedHtml[i][1] );
} else {
itemHtml = annotatedHtml[i];
itemAnnotations = new ve.dm.AnnotationSet( store );
}
ve.dm.Converter.openAndCloseAnnotations( annotationStack, itemAnnotations,
openAnnotation, closeAnnotation
);
// Handle the actual HTML
if ( typeof itemHtml === 'string' ) {
buffer += itemHtml;
} else {
flushBuffer();
$current.append( itemHtml );
}
}
flushBuffer();
return $wrapper.contents();
};
/**
* Render contents.
*
* @method
*/
ve.ce.ContentBranchNode.prototype.renderContents = function () {
if ( this.root instanceof ve.ce.DocumentNode && !this.root.getSurface().isRenderingEnabled() ) {
return;
}
// Detach all child nodes from this.$
// We can't use this.$.empty() because that destroys .data() and event handlers
this.$.contents().each( function () {
$( this ).detach();
} );
// Reattach child nodes with the right annotations
this.$.append( this.getRenderedContents() );
// Add slugs
this.setupSlugs();
// Highlight the node in debug mode
if ( ve.debug ) {
this.$.css( 'backgroundColor', '#F6F6F6' );
setTimeout( ve.bind( function () {
this.$.css( 'backgroundColor', 'transparent' );
}, this ), 350 );
}
};