This class provides an example custom link
recogniser tailored to the needs of the non-xlink
links used by XBRL.
XBRL XLink Handler
This class provides a real world example of an XLink handler for XBRL.
Package org.xbrlapi.xlink.handler Description
Defines XLink event handling required for XBRL DTS discovery.
This package contains a custom XBRL XLink handler
and a custom link recogniser tailored to the requirements
of XBRL DTS discovery.
The key steps involved in XLink handling to
discover an XBRL DTS are set out below:
Take, as input, one or more URI's that can be resolved to
an XML document. These constitute the discovery starting points.
Traverse all XLinks and custom links in those documents,
identifying any link destinations that are external to the
starting point XML documents.
Augment the initial set of starting point documents with the newly
discovered XML documents to get the set of discovered documents.
Traverse all XLinks and custom links in the newly discovered XML
documents, again identifying any link destinations external to the
existing set of discovered documents.
Continue the above discovery process until the resulting set of
discovered XML documents is closed in the sense that none of the
XLinks or other custom links in them resolve to destinations that
are not internal to one of the discovered XML documents.
Once the DTS has been discovered, augment the information
in the DTS to ensure that the DTS has a signature (the URLs
of the XML documents used to seed the discovery process) and
to ensure that the links in it are easily navigated by software
that is not XLink enabled. Specifically the XBRL XLink handler
- Augment the XML documents in the DTS with XML markup (in a
new namespace "http://xbrlapi.org/linking") that documents
the absolute URI's that were used to obtain each XML
document (providing a signature for the DTS).
- Augment the XML nodes that are either XLink elements or custom-links
or XML fragments that are linked to by XLinks or custom links,
with an attribute, in the new namespace, "http://xbrlapi.org/linking",
that is unique within the XML structure that results from XLink
processing (to enable ID-based O(1) link traversal operations
within the resulting XML structure).
- Augment the XLink locators with a child element for each XLink arc
that connects to or from it. The child element must be in the
"http://xbrlapi.org/linking" namespace and must contain the unique
XLink id attribute of the the arc. This aids in the
efficiency of navigation from the locators to the arcs.
- Augment the XLink arcs with a child element for each locator or
resource that it connects to. The child element in the new
namespace needs to contain an attribute equal to the unique id
given in the new namespace to the relevant locator or resource.
- Augment each local or remote resource with an element in the new
namespace, containing an attribute equal to the new unique id
of the locator (for remote resources) or arc (for local resources)
that connects to it.
All of these new id attribute values and elements enable ID-based
O(1) link traversal operations within the DTS.
- What to do about simple links to fragments of XML documents?
Do the entire XML documents get included in the DTS or just
the fragments that are addressed by the simple links?
- What to do about locators that reference resources in linkbases
that are external to the extended link that contains the
locators? Should the entire extended link containing the
resources be included in the DTS?
- The whole system of additional markup to assist in
efficient relationship navigation would be nice to
replace by some kind of XLink/XPointer handling
software that deals with the relationship navigation
directly. This is tough at the moment because it is
hard, for example, to find from the remote resources
the locators that reference them. Vat to do? Vat to do?
xbrlapi.org Java library providing XBRL functionality
Copyright (C) 2005, Geoffrey Shuetrim (firstname.lastname@example.org)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License (http://www.gnu.org/licenses/lgpl.html), or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA