Searches for the BASE URL. The code should work on both XML and HTML document even if base mechanisms are completely different. It returns the base as defined in RFC 2396 sections 5.1.1. Base URI within Document Content and 5.1.2. Base URI from the Encapsulating Entity However it does not return the document base (5.1.3), use {xmlDocumentGetBase} for this
Return value:
Return the base URL as a string, or an empty string if cannot be retrieved.