xModify Overview

Ajax has changed web applications from stateless, page-based application into stateful, highly responsive ones. Developers use the XHR object to load data and content from the server and update the state of the page by changing the HTML DOM. This is typical done by retrieving data in the form of XML or JSON. Once on the client, the developer will looping over the dataset using JavaScript and insert, replace or modify HTML DOM elements. This can require lots of JavaScript even if the developer uses a library such as jQuery, MooTools, ...

XAP has incorporated an XML syntax called xModify that can be used to create or update XML, XAL, and HTML elements declaratively. This means that developers can utilize server-side frameworks to create XML modify documents that an xModify Processor will use to update the HTML or XAL document.

xModify Workflow

Why is this Helpful?

Because, instead of having to create JavaScript to update the UI for a particular dataset, the developer can use server-side functionality such as PHP, J2EE, Ruby, or XSLT to create XML documents that can to the same thing. This typically will save code, time and increase the maintainablity of the application.

The second reason xModify is helpful is that it puts the know-how into a well defined XML layer, instead of either a client-side or server-side library. XML can be outputted from any server-side or processed client-side layer, making it more likely that knowledge of xModify can be leveraged across projects.

Operations

xModify contains a set of operation that a developer would need to perform when manipulating a XML or HTML DOM.

Each of the operations contains a select attribute that is used to select a set of operations.

• append

  Append the children of the operation to the selected nodes

• clone

  Create a clone of the selected nodes.

• insert-after

  Insert the children of the operation after the selected nodes

• insert-at

  Insert the children of the operation at a specific index of the selected nodes

• insert-before

  Insert the children of the operation before the selected nodes

• remove-attribute

  Remove an attribute from the selected nodes

• remove-element

  Remove the selected nodes.

• replace

  Replace the selected nodes with the children of the operation.

• replace-children

  Replace the children of selected nodes with the children of the operation.

• set-attribute

  Change an attribute of the selected nodes.

• set-innerhtml

  Change the HTML of the selected nodes to be the children of the operation.

• embed-xal

  Embed XAL components of the operation into the selected nodes.