gecko-dev/content/base/src/nsScriptElement.h

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Code.
 *
 * The Initial Developer of the Original Code is
 * Mozilla Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2006
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Jonas Sicking <jonas@sicking.cc> (original developer)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * ***** END LICENSE BLOCK ***** */

#include "nsIScriptLoaderObserver.h"
#include "nsIScriptElement.h"
#include "nsStubMutationObserver.h"
#include "prtypes.h"

/**
 * Baseclass useful for script elements (such as <xhtml:script> and
 * <svg:script>). Currently the class assumes that only the 'src'
 * attribute and the children of the class affect what script to execute.
 */

class nsScriptElement : public nsIScriptElement,
                        public nsStubMutationObserver
{
public:
  // nsIScriptLoaderObserver
  NS_DECL_NSISCRIPTLOADEROBSERVER

  // nsIMutationObserver
  NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED
  NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
  NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
  NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED

  nsScriptElement(mozilla::dom::FromParser aFromParser)
    : nsIScriptElement(aFromParser)
  {
  }

protected:
  // Internal methods

  /**
   * Check if this element contains any script, linked or inline
   */
  virtual PRBool HasScriptContent() = 0;

  /**
   * Processes the script if it's in the document-tree and links to or
   * contains a script. Once it has been evaluated there is no way to make it
   * reevaluate the script, you'll have to create a new element. This also means
   * that when adding a src attribute to an element that already contains an
   * inline script, the script referenced by the src attribute will not be
   * loaded.
   *
   * In order to be able to use multiple childNodes, or to use the
   * fallback mechanism of using both inline script and linked script you have
   * to add all attributes and childNodes before adding the element to the
   * document-tree.
   */
  virtual nsresult MaybeProcessScript();
};