Copyright ©2011 XBRL International Inc., All Rights Reserved.
Circulation of this Public Working Draft is unrestricted. This document is normative. Other documents may supersede this document. Recipients are invited to submit comments to rendering-feedback@xbrl.org, and to submit notification of any relevant patent rights of which they are aware and provide supporting documentation.
This document specifies semantics and syntax constraints for selection axes. Selection axes provide an implementation of open axes, as defined in the table specification, based on the use of XPath expressions that select a sequence of data (not necessarily fact items), which is given a name, and usable as a variable in breakdown (nested) axes of the same axis disposition, and usable in axes expressions of the opposite axis disposition (when orthogonal to the selection axis coordinate).
1 Hugh Wallis:This is an early list - to be updated
1 Introduction
2 Namespaces and namespace prefixes
3 Definitions
4 Coordinate ordering
5 Context Item
6 Selection
7 Headers
8 Syntax
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
This document specifies semantics and syntax constraints for selection axes. Selection axes provide an implementation of open axes, as defined in the table specification, based on the use of XPath expressions that select a sequence of data (not necessarily fact items), which is given a name, and usable as a variable in breakdown (nested) axes of the same axis disposition, and usable in axes expressions of the opposite axis disposition (when orthogonal to the selection axis coordinate).
(In a most general sense, if the predefinedRuleAxes and filterAxes were thought of in the same manner as fact variables for formula variable sets, the selection axes may be thought of as general variables for the table, as a simile of a variable set.)
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 are consistent
with Table 1.
The prefix column in Table 1 is non normative. The namespace URI column is normative.
Prefix | Namespace URI |
---|---|
table
|
http://xbrl.org/2011/table
|
xbrlte
|
http://xbrl.org/2011/table/error
|
link
|
http://www.xbrl.org/2003/linkbase
|
xbrli
|
http://www.xbrl.org/2003/instance
|
xfi
|
http://www.xbrl.org/2005/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
|
generic
|
http://xbrl.org/2007/generic
|
The figure below provides a model of the selection axis.
A selection axis is an implementation of open axes expressed in terms of an XPath function that yields a sequence.
Examples of selection axes fulfill these use cases:
The XPath selection expression produces a sequence. Although most XPath operations result in sequences that are in source instance document node order, sequences may be sorted (such as account code or name, using custom functions such as described in [XPATH SORTING]).
The context item for the XPath expression of a selection may be a fact item, if the inherited axes of the selection axis, together with the coordinates of the opposite direction axisType coordinates, specify a fact item, or otherwise an empty sequence.
A selection yields any node of an instance or atomic data produced by an XPath expression.
If a nonabstract selectionAxis is the last coordinate for an axis, the select expression provides a way of generating renderable data from a otherwise-bound fact for a cell. For example, if the inheriting coordinates identify a fact, then the select expression may produce an aspect of the fact, such as a period end date or unit, or a footnote (or footnotes sequence), or any other data derived by table lookup.
<xtable:selectionAxis>
is an element with attributes @name
and @select
.
@name
(on the axis-arc relationship) behaves like a variable name, so that the selection value can be referred to by XPath construct $name
.
@coveredAspect
: an enumeration type specifying what aspect is to be matched and covered. Enumeration values may be
[Hugh Wallis: This is an early list - to be updated]:
Concept
: the value of the selection is a QName which matches a fact’s QName and covers the concept aspect.PeriodStart
: the value of the selection is a dateTime (union) value which matches a fact’s start and covers the period aspect.PeriodInstantEnd
: the value of the selection is a dateTime (union)
value which matches a fact’s instant or end and covers the period aspect.PeriodInstant
: the value of the selection is a dateTime (union)
value which matches a fact’s instant only, and covers the period aspect..PeriodEnd
: the value of the selection is a dateTime (union)
value which matches a fact’s end only, and covers the period aspect..EntityIdentifier
: the value of the selection is an entity identifier (token) value which matches a fact’s entity identifier
and covers the entity identifier aspect
Unit
: the value of the selection is a QName which matches a single-measure unit and covers the unit aspect
@match
expression (if present) specifies a boolean
match expression (where the context item is a fact being matched to the selected dimension, available as the named value of the selection.
@select
is an XPath expression yielding a sequence of nodes (of instance document), atomic values
(displayable), or opaque objects (relationships from xfi: relationship functions, but must be abstract).
The following attributes are inherited from openAxis and may be used on a selectionAxis resource element:
@value
: An XPath expression applied to a coordinate location (cell of table) after selection is assigned to the selectionAxis.
The @value
is not assigned to the selection yielded as a coordinate value, but only available to format transform, scale, and rendering.
@scale
: Scaling for rendering without affecting the selection yielded
@negate
: If true
specifies that a numeric value is to be sign-flipped on rendering.
@format
: Format transformation applied to rendering, without affecting the selection yielded
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/2011/
- 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/2011/selection-axis.xsd.
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This document could not have been written without the contributions of many people.
Date | Author | Details |
---|---|---|
01 October 2011 | Herm Fischer |
Initial draft |
11 October 2011 | Hugh Wallis |
Incorporated some changes proposed by Victor Morilla preparatory to creating DPWD |
05 December 2011 | Herm Fischer |
Update class diagram, provide schema definitions. |
19 December 2011 | Herm Fischer |
Editorial updates suggested by Roland Hommes in WG e-mail of 2011-12-08. |
This appendix contains a list of the errata corrections that have been incorporated into this document. This represents all those errata corrections that have been approved by the XBRL International Rendering Working Group up to and including 21 December 2011.
No errata have been incorporated into this document.