Copyright ©2009 XBRL International Inc., All Rights Reserved.
Circulation of this Recommendation is unrestricted. This document is normative. Recipients are invited to submit comments to formula-feedback@xbrl.org, and to submit notification of any relevant patent rights of which they are aware and provide supporting documentation.
1 Introduction
1.1 Background
1.2 Relationship to other work
1.3 Language independence
1.4 Terminology
1.5 Document conventions (non-normative)
1.6 Namespaces and namespace prefixes
1.7 XPath usage
2 Syntax
2.1 Single-measure unit filter
2.2 General unit filter
A Normative schema
B References
C Intellectual property status (non-normative)
D Acknowledgements (non-normative)
E Document history (non-normative)
F Errata corrections in this document
1 Namespaces and namespace prefixes
1 Single-measure unit filters
2 General unit filters
This specification is an extension to [VARIABLES]. It defines XML syntax [XML] for filters that can condition on units of measurement when selecting facts from XBRL instances.
All of the filters defined in this specification can cover the unit aspect.
This specification is a member of a suite of similar specifications that define specific types of criteria that can be used to select facts from XBRL instances. It enhances the fact selection capabilities of the XBRL Variables Specification [VARIABLES].
This specification depends upon the XBRL Specification [XBRL 2.1], and the XBRL Variables Specification [VARIABLES]. In the event of any conflicts between this specification and the specifications upon which it depends, this specification does not prevail.
The official language of XBRL International's own work products is English and the preferred spelling convention is UK English.
This specification is consistent with the definitions of any of the terms defined in specifications that it depends on.
Documentation conventions follow those set out in the XBRL Variables Specification [VARIABLES].
Namespace prefixes [XML NAMES] will be used
for elements and attributes in
the form ns:name where ns is the
namespace prefix and name is the local name.
Throughout this specification, the mappings
from namespace prefixes to actual namespaces is consistent
with
Table
1.
The prefix column in Table 1 is non normative. The namespace URI column is normative.
| Prefix | Namespace URI |
|---|---|
uf
|
http://xbrl.org/2008/filter/unit
|
xbrlufe
|
http://xbrl.org/2008/filter/unit/error
|
eg
|
http://example.com/
|
fn
|
http://www.w3.org/2005/xpath-functions
|
link
|
http://www.xbrl.org/2003/linkbase
|
xbrli
|
http://www.xbrl.org/2003/instance
|
xfi
|
http://www.xbrl.org/2008/function/instance
|
xbrldi
|
http://xbrl.org/2006/xbrldi
|
xbrldt
|
http://xbrl.org/2005/xbrldt
|
xl
|
http://www.xbrl.org/2003/XLink
|
xlink
|
http://www.w3.org/1999/xlink
|
xs
|
http://www.w3.org/2001/XMLSchema
|
xsi
|
http://www.w3.org/2001/XMLSchema-instance
|
gen
|
http://xbrl.org/2008/generic
|
variable
|
http://xbrl.org/2008/variable
|
iso4217
|
http://www.xbrl.org/2003/iso4217
|
This specification only provides a textual declaration of syntax constraints when those constraints are not expressed by the normative schema supplied with this specification.
Explanations of elements and attributes are only supplied when explanations are not already provided in other specifications.
Unless explicitly stated otherwise, a reference to a specific element MUST be read as a reference to that element or to any element in its substitution group.
A single-measure unit filter is declared by an
<uf:singleMeasure>
element.
The syntax for the
<uf:singleMeasure>
element is defined by the normative schema supplied with this specification.
The single-measure unit filter can be used to match facts that are reported with a unit that is specified by a single measure.
The XPath expression implied by a single-measure unit filter is:
xfi:is-numeric(fn:node-name(.)) and count(xfi:unit-numerator(xfi:unit(.))) eq 1 and
count(xfi:unit-denominator(xfi:unit(.))) eq 0 and
xfi:measure-name(xfi:unit-numerator(xfi:unit(.))[1]) eq #measure
where #measure is the value of the
<uf:qnameExpression>
element if that element is contained by the
<uf:measure>
element and
#measure is given by fn:QName(#namespace, #name)
if the
<uf:qname>
element is contained by the
<uf:measure>
element. #namespace
is the namespace for the QName specified as the content of the
<uf:qname>
element and #name is the local name for the QName
specified as the content of the
<uf:qname>
element.
| Filter1 | Selection criteria |
|---|---|
|
<uf:singleMeasure>
<uf:measure> </uf:singleMeasure><uf:qname> </uf:measure>eg:squareMiles </uf:qname> |
The units of measurement must be reported with a single measure QName that is equal to eg:squareMiles. Non-numeric facts and facts reported with units of measurement represented by several measures are all rejected by this filter. |
1. XLink attributes have been omitted.
A general unit filter is declared by an
<uf:generalMeasures>
element.
The syntax for the
<uf:generalMeasures>
element is defined by the normative schema supplied with this specification.
The general unit filter can be used to select facts based on criteria that involve a number of unit measures.
The XPath expression implied by a general unit filter is:
xfi:is-numeric(fn:node-name(.)) and
xfi:unit(.)[#test]
where #test is the value of the
@test
attribute on the general unit filter.
| Filter1 | Selection criteria |
|---|---|
|
<uf:generalMeasures test="exists(xbrli:divide)"/>
|
The filter rejects facts if they are not reported with a unit of measure that involves both a numerator and a denominator. |
|
<uf:generalMeasures test="count(xbrli:divide/xbrli:numerator/xbrli:measure) eq 1 and xbrli:divide/xbrli:numerator/xbrli:measure eq fn:QName('http://xbrl.org/formula/conformance/example','eg:kilometers') and count(xbrli:divide/xbrli:denominator/xbrli:measure) eq 1 and xbrli:divide/xbrli:denominator/xbrli:measure eq fn:QName('http://xbrl.org/formula/conformance/example','eg:hours')"/>
|
The filter rejects facts if they are not reported with
a unit of measure that is expressed as a single numerator measure with
a QName, eg:kilometers and a single denominator measure with
a QName, eg:hours. |
1. XLink attributes have been omitted.
The following is the XML schema provided as part of this specification. This is normative. Non-normative versions (which should be identical to these except for appropriate comments indicating their non-normative status) are also provided as separate files for convenience of users of the specification.
NOTE: (non-normative) Following the schema maintenance policy of XBRL International, it is the intent (but is not guaranteed) that the location of non-normative versions of these schemas on the web will be as follows:
http://www.xbrl.org/2008/ - during the drafting process for
this specification this directory should contain a copy of the
most recent published version of the schema at
http://www.xbrl.org/2008/unit-filter.xsd.
This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to XBRL International or XBRL organizations, except as required to translate it into languages other than English. Members of XBRL International agree to grant certain licenses under the XBRL International Intellectual Property Policy (www.xbrl.org/legal).
This document and the information contained herein is provided on an "AS IS" basis and XBRL INTERNATIONAL DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
The attention of users of this document is directed to the possibility that compliance with or adoption of XBRL International specifications may require use of an invention covered by patent rights. XBRL International shall not be responsible for identifying patents for which a license may be required by any XBRL International specification, or for conducting legal inquiries into the legal validity or scope of those patents that are brought to its attention. XBRL International specifications are prospective and advisory only. Prospective users are responsible for protecting themselves against liability for infringement of patents. XBRL International takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Members of XBRL International agree to grant certain licenses under the XBRL International Intellectual Property Policy (www.xbrl.org/legal).
This document could not have been written without the contributions of many people including the participants in the Formula Working Group.
| Date | Author | Details |
|---|---|---|
| 18 December 2006 | Geoff Shuetrim |
First internal working draft created, drawing extensively on the previous Formula specification drafts. |
| 25 April 2007 | Geoff Shuetrim |
Changed the target namespace of the normative schema. |
| 08 May 2007 | Geoff Shuetrim |
Added clarification about the fact aspect covered by the filters defined in this specification. |
| 29 May 2007 | Geoff Shuetrim |
Changed the target namespace of the normative schema again. Modified the general unit filter to have a structure that is more consistent with the structure used for other filters. Changed the $x notation to #x to be consistent with other filter specifications. |
| 24 July 2007 | Hugh Wallis |
Edited for public working draft publication. |
| 05 November 2007 | Geoff Shuetrim |
Converted the specification to XML format. Added in the definitions and the hyperlinks to the relevant sections of the normative schema. Fixed up the single measure filter naming inconsistencies. |
| 12 November 2007 | Geoff Shuetrim |
Linked all of the external terminology references back to bibliographic citations. |
| 30 November 2007 | Geoff Shuetrim |
Added examples.
Changed |
| 02 December 2007 | Geoff Shuetrim |
Changed additional |
| 02 December 2007 | Herm Fischer |
Changed count(nodelist) operator to exists(nodelist) in the example XPath expressions. |
| 31 January 2008 | Geoff Shuetrim |
Standardised the format of the hyperlinks to the normative schema.
Changed |
| 17 April 2008 | Geoff Shuetrim |
The QName constants in the example using kilometer and hour measures have been changed to use the fn:QName() function rather than a string representation of the QName, as suggested by Herm Fischer. |
| 27 November 2008 | Geoff Shuetrim |
The implied XPath expressions have been aligned to the latest versions of the functions in the XBRL function registry, resolving discrepancies identified by Nathan Summers. |
| 15 December 2008 | Geoff Shuetrim |
Updated references to the latest errata-corrected version of the XBRL 2.1 specification. |
This appendix contains a list of the errata that have been incorporated into this document. This represents all those errata corrections that have been approved by the XBRL International Formula Working Group up to and including 22 June 2009. Hyperlinks to relevant e-mail threads may only be followed by those who have access to the relevant mailing lists. Access to internal XBRL mailing lists is restricted to members of XBRL International Inc.
No errata have been incorporated into this document.