Recently Xopus, a browser based XML editor, attracted some attention. This stimutated us for a review. The editor itself is completely written in javascript and relies on the MSXML ActiveX component and is therefore not working with FireFox and Opera :-(.
It offers different views for editing the xml but the main feature is the WYSIWYG xml editor. This is provided by on-the-fly transformation of the xml using an xml specific xml stylesheet. The editor provides functionality to lookup and reference data (like a foreign key) using xml based LOV’s (list of values). With a two step process, based on XInclude, this referenced data can then be presented (but not modified) in the editor. Besides text it is also possible to include/reference other content like images or multimedia.
On the Xopus website two trial versions are available: a stand-alone application and a webserver version. Both contain some limitations in relation to opening and saving of the xml document, but give a good impression of the possibilities. The installation is very straightforward, just extract the zipfile in the correct directory (e.g. in the Tomcat webapps/ROOT dir).
The demo is very comprehensive and with the stand-alone trial version it is also very simple to work with a custom xml and xslt.
To investigate the integration of Xopus with other (J2EE) applications a very simple servlet was developed and deployed on a Tomcat server. The servlet can be accessed via HTTP – POST. With a simple, documented, ‘hack’ (var result = Application.sendXML(xmldoc, 'POST', url);) in the Xopus datadriver.js file the XML can be submitted (in the body of the HTTP request) to the servlet. This worked for both trial versions. Unfortunately I was not able to circumvent the limitations to retrieve a remote xml file.
Summary;
Xopus is a very promising product and provides excellent user-friendly xml editing options. Extensive knowledge of xml stylesheets is required for creating the user-interface. Although the integration with other products could not be fully investigated, these options are available in the production version. Other products, like the Apache CMS Lenya already provide integration for Xopus. Especially the integration with the Oracle XMLDB holds many promises.
