Relative and Absolute URLs
The notion of relative hyperlinks (HREFs) exists only within the context of HTML pages. In Windchill, relative HREFs are used within static HTML pages and the static portions of HTML template files. Absolute HREFs are used for all dynamically generated HREFs.
A typical dynamically generated Windchill HTML page includes the following:
• A <BASE> tag, specifying an absolute URL to the static Windchill codebase as configured by the wt.server.codebase property.
• Relative HREFs to static resources.
• Absolute HREFs to other dynamically generated pages.
Most Windchill HTML pages are generated from HTML template files. Templates are allowed to contain HREFs to other static resources (such as images, backgrounds, and stylesheets), without requiring the links to be generated by script calls if the document base is specified as the root of the Windchill virtual directory. To make sure the template’s contents are not tightly coupled with the request URL, the <BASE> tag is dynamically generated using a script code. This allows a response template to be shared by many requests that may have a variable number of PATH_INFO elements. Links to other dynamically generated pages (via servlets) are also generated by script calls and product-absolute HREFs.
Most dynamically generated HREFs share some URL components (for example, protocol, host, port, and path prefix) with the base URL of the pages containing them. It should be possible for Windchill to generate relative HREFs into the pages. However, most Windchill code currently uses java.net.URL objects internally when generating HREFs, and there is no such thing as a relative java.net.URL object. Thus, it is currently not possible to configure Windchill to generate all HREFs as relative links. If it were possible, it would still not be advisable to access a Windchill system using more than one base URL, such as using one URL for internal users and another for external users accessing through a reuse proxy. Although this might not result in changes to the internal system's configuration, host names and URLs are not used only in HTTP requests and responses. Host names also appear in RMI stubs, and URLs also appear in HTML email.
Enterprise deployments, reverse proxy configuration, in particular, should use single, application-specific host name aliases to enable controlling network connectivity through name resolution, as described in the next section.