1 Introduction

This specification is an extension to the XBRL Variables 1.0 Specification [VARIABLES]. It defines syntax for filters that condition upon the location of facts relative to tuple structures in XBRL instances.

The following kinds of location-specific information can be conditioned upon by the filters defined in this specification:

the name of the parent tuple
the name of an ancestor tuple
whether the fact that another fact variable has evaluated to is a sibling of the fact being filtered
whether the fact that another fact variable has evaluated to is at a specified location within the target XBRL instance

All of the filters defined in this specification can cover the location aspect.

1.1 Background

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].

1.2 Relationship to other work

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.

1.3 Language independence

The official language of XBRL International's own work products is English and the preferred spelling convention is UK English.

1.4 Terminology

This specification is consistent with the definitions of any of the terms defined in specifications that it depends on.

1.5 Document conventions (non-normative)

Documentation conventions follow those set out in the XBRL Variables Specification [VARIABLES].

1.6 Namespaces and namespace prefixes

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.

Table 1: Namespaces and namespace prefixes

Prefix	Namespace URI
`tf`	`http://xbrl.org/2008/filter/tuple`
`xbrltfe`	`http://xbrl.org/2008/filter/tuple/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`

1.7 XPath usage

XPath usage is identical to that in the XBRL Variables Specification [VARIABLES].

2 Syntax

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.

2.1 Parent filter

A parent filter is declared by an <tf:parentFilter> element.

The syntax for the <tf:parentFilter> element is defined by the normative schema supplied with this specification.

The parent filter can be used to select facts that have a specified parent element.

If the <tf:parent> element contains a <cf:qnameExpression> element, then the XPath expression implied by the parent filter is:

(fn:node-name(..) eq #qnameExpression)

where #qnameExpression is the XPath expression contained by the tf:qnameExpression element.

If the <tf:parent> element contains a <tf:qname> element, then the implied XPath expression is:

(fn:node-name(..) eq fn:QName(#namespace,#name))

where #namespace is the namespace for the QName specified as the content of the <tf:qname> element and #name is the local name for the QName specified as the content of the <tf:qname> element.

Example 1: Parent filters

Parent QName	Implied constraint
`xbrli:xbrl`	The fact must not be contained by a tuple.
`eg:mytuple`	The fact must be a child element of a tuple with the QName `<eg:mytuple>`.

2.2 Ancestor filter

An ancestor filter is declared by an <tf:ancestorFilter> element.

The ancestor filter can be used to select facts that have a specified ancestor element.

The syntax for the <tf:ancestorFilter> element is defined by the normative schema supplied with this specification.

If the <tf:ancestor> element contains a <cf:qnameExpression> element, then the XPath expression implied by the ancestor filter is:

fn:not(fn:empty(ancestor::*[fn:node-name(.) eq #qnameExpression]))

where #qnameExpression is the XPath expression contained by the tf:qnameExpression element.

If the <tf:ancestor> element contains a <tf:qname> element, then the implied XPath expression is:

fn:not(fn:empty(ancestor::*[fn:node-name(.) eq fn:QName(#namespace,#name)]))

Example 2: Ancestor filters

Ancestor QName	Implied constraint
`xbrli:xbrl`	The fact must be contained by an XBRL instance (Note that this is a redundant constraint because all XBRL facts must be contained by an XBRL instance.
`eg:mytuple`	The fact must be contained by a tuple with the QName `<eg:mytuple>` but it does not have to be a child of that element.

2.3 Sibling filter

A sibling filter is declared by an <tf:siblingFilter> element.

The sibling filter can be used to select facts that are siblings of an another fact.

The syntax for the <tf:siblingFilter> element is defined by the normative schema supplied with this specification.

The XPath expression implied by the sibling filter is:

.. is $#variable[1]/..

where #variable is the value of the @variable attribute on the sibling filter.

Example 3: Sibling filters

Variable QName	Implied constraint
`eg:variableA`	The fact must be a sibling of the fact that variable `<eg:variableA>` has evaluated to. If variable `<eg:variableA>` has evaluated to a sequence of facts, then the fact must be a sibling of any one of the facts in that sequence.

2.4 Location filter

A location filter is declared by an <tf:locationFilter> element.

The location filter can be used to select facts that have a specified location relative to the location of another fact.

The syntax for the <tf:locationFilter> element is defined by the normative schema supplied with this specification.

The XPath expression implied by the location filter is:

(some $filter:candidate in #location, $filter:fact in $#variable satisfies $filter:candidate is $filter:fact)

where #variable is the value of the @variable attribute on the location filter and #location is the value of the @location attribute on the location filter.

Example 4: Location filters

Variable QName	Location	Implied constraint
`eg:variableA`	`../*`	The fact that variable `<eg:variableA>` has evaluated to must be a child of the element that is the parent of the fact being filtered.
`eg:variableA`	`../eg:aTuple/*`	The fact that variable `<eg:variableA>` has evaluated to must be a child of an `<eg:aTuple>` tuple element that is a sibling of the fact being filtered.

Appendix A Normative schema

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:

While any schema is the most current RECOMMENDED version and until it is superseded by any additional errata corrections a non-normative version will reside on the web in the directory 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/tuple-filter.xsd.
A non-normative version of each schema as corrected by any update to the RECOMMENDATION will be archived in perpetuity on the web in a directory that will contain a unique identification indicating the date of the update.

</choice>

</complexType>

</sequence>

</extension>

</complexContent>

</complexType>

</element>

</sequence>

</extension>

</complexContent>

</complexType>

</element>

</extension>

</complexContent>

</complexType>

</element>

</extension>

</complexContent>

</complexType>

</element>

</schema>

Appendix B References

VARIABLES: XBRL International Inc.. "XBRL Variables 1.0"
Phillip Engel, Herm Fischer, Victor Morilla, Jim Richards, Geoff Shuetrim, David vun Kannon, and Hugh Wallis.
(See ../../variables/REC-2009-06-22/variables-REC-2009-06-22.html)
XBRL 2.1: XBRL International Inc.. "Extensible Business Reporting Language (XBRL) 2.1"
Phillip Engel, Walter Hamscher, Geoff Shuetrim, David vun Kannon, and Hugh Wallis.
(See http://www.xbrl.org/Specification/XBRL-RECOMMENDATION-2003-12-31+Corrected-Errata-2008-07-02.htm)
XML NAMES: W3C (World Wide Web Consortium). "Namespaces in XML 1.0 (Second Edition)"
Tim Bray, Dave Hollander, Andrew Layman, and Richard Tobin.
(See http://www.w3.org/TR/REC-xml-names/)
XML SCHEMA STRUCTURES: W3C (World Wide Web Consortium). "XML Schema Part 1: Structures Second Edition"
Henry S. Thompson, David Beech, Murray Maloney, and Noah Mendelsohn.
(See http://www.w3.org/TR/xmlschema-1/)

Appendix C Intellectual property status (non-normative)

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).

Appendix D Acknowledgements (non-normative)

This document could not have been written without the contributions of many people including the participants in the Formula Working Group.

Appendix E Document history (non-normative)

Date	Author	Details
28 March 2007	Geoff Shuetrim	First internal working draft created.
25 April 2007	Geoff Shuetrim	Created and inserted the normative schema for tuple filters. Modified the tuple-location filter to check all facts in the sequence of facts from a fact variable rather than the first fact in that sequence.
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.
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. Added examples for each of the filters. Removed the erroneous dynamically determined variable qname structures from the sibling and location filters. Renamed the filter elements.
05 November 2007	Geoff Shuetrim	Added a note to ensure that we check that the filters in this specification will work as expected given the design of the XPath expression implied by fact variables. The xfi:facts-in-instance() function is at the heart of this issue.
24 January 2008	Geoff Shuetrim	Made the `@variable` attribute on the sibling filter and the location filter required in the normative schema.
31 January 2008	Geoff Shuetrim	Standardised the format of the hyperlinks to the normative schema. Changed `xs:QName()` to `fn:QName()` as suggested by Masatomo Goto.
12 February 2008	Geoff Shuetrim	Converted remaining general equality tests to value equality tests in the implied XPath expressions.
07 March 2008	Geoff Shuetrim	Modified the implied XPath expression for the location filter to ensure that it returns an effective Boolean value. The issue was identified by Hitoshi Okumura.
17 November 2008	Geoff Shuetrim	Made the `@variable` attribute have type `variable:QName` because it contains variable name QNames that do not resolve according to the rules used for QNames with data type xs:QName. This change was suggested by Herm Fischer.
18 November 2008	Geoff Shuetrim	Changed "sibling" to "location" in the paragraph explaining the implied XPath expression for location filters.
19 March 2009	Geoff Shuetrim	Changed the implied XPath expressions for the ancestor filter to ensure that the filters can handle sequences of ancestors rather than just a single ancestor.

Appendix F Errata corrections in this document

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.

Tuple Filters 1.0

Recommendation 22 June 2009

Status

Abstract

Table of Contents

Appendices

Table

Examples

Definitions

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 Parent filter

2.2 Ancestor filter

2.3 Sibling filter

2.4 Location filter

Appendix A Normative schema

Appendix B References

Appendix C Intellectual property status (non-normative)

Appendix D Acknowledgements (non-normative)

Appendix E Document history (non-normative)

Appendix F Errata corrections in this document