Basic web security model

Editor's Notes

• #9: The Document Object Model (DOM) is a programming API for HTML and XML documents. It defines the logical structure of documents and the way a document is accessed and manipulated. In the DOM specification, the term "document" is used in the broad sense - increasingly, XML is being used as a way of representing many different kinds of information that may be stored in diverse systems, and much of this would traditionally be seen as data rather than as documents. Nevertheless, XML presents this data as documents, and the DOM may be used to manage this data. With the Document Object Model, programmers can create and build documents, navigate their structure, and add, modify, or delete elements and content. Anything found in an HTML or XML document can be accessed, changed, deleted, or added using the Document Object Model, with a few exceptions - in particular, the DOM interfaces for the internal subset and external subset have not yet been specified. As a W3C specification, one important objective for the Document Object Model is to provide a standard programming interface that can be used in a wide variety of environments and applications. The Document Object Model can be used with any programming language. In order to provide precise, language-independent specification of the Document Object Model interfaces, we have chosen to define the specifications in OMG IDL, as defined in the CORBA 2.2 specification. 
• #37: Event handling has been part of JavaScript since the language's inception. They refer to specific, user imitated actions within the webpage, such as the moving of your mouse over a link, the clicking on a link, or submission of a form. Thanks to event handling, our scripts are more interactive and are able to perform certain actions depending on the user's. The DOM of modern web browsers such as IE5+, NS6+, and Firefox provide expanded methods and flexibility (relative to older browsers) for capturing events. The 2 traditional ways of assigning event handlers The 2 common and conventional ways of setting up an event handler- via HTML, or scripting. In both cases, a function or code is attached at the end, which is executed when the handler detects the specified event. Via HTML, using attributes We can define an event handler directly inside the relevant HTML tag, by embedding it as a attribute. A piece of JavaScript is also included to tell the browser to perform something when the event occurs. For example, <a href="http://freewarejava.com" onMouseover="window.status='Click here for Java applets';return true" onMouseout="window.status=''">Freewarejava.com</a> 2) Via scripting We can also assign and set up event handlers to elements using scripting, and inside your script . This allows for the event handlers to be dynamically set up, without having to mess around with the HTML codes on the page. When setting up event handlers for an element directly inside your script, the code to execute for the events must be defined inside a function. <a ID="test" href="http://freewarejava.com">Freewarejava.com</a>   <script type="text/javascript">   function changestatus(){ window.status="Click here for Java applets" return true }   function changebackstatus(){ window.status='' }   document.getElementById("test").onmouseover=changestatus document.getElementById("test").onmouseout=changebackstatus   </script>