Copyright ©2007 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 the authors and contributors, and to submit notification of any relevant patent rights of which they are aware and to provide supporting documentation.
This specification is an extension to the XBRL Validations
specification [VALIDATION].
It specifies the syntax for assertions that define a test on
the values bound to the variables of a given variable set.
It is a construct similar to that of a formula resource, but its output
is a Boolean value instead of a complete XBRL fact. The test is
determined
by the result of the XPath expression contained in the @test
attribute of the assertion resource.
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 Value Assertions
2.2 Value assertions relationships
3 Test implied by value assertions
4 The processing model for value assertions
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
rfc2119 terminology
value assertion
value assertion expression
This specification is an extension to the XBRL Validation
specification [VALIDATION].
It defines XML syntax [XML]
for assertions that test
the values of the variables of each evaluation of a given variable set.
It is a construct similar to that of a formula resource, but its output
is a boolean value instead of a complete XBRL fact. The test is
determined
by the result of the XPath expression contained in the @test
attribute of the assertion resource.
This kind of assertion facilitates the definition of business rules that perform checks like those set out in Example 1.
Many of the syntax constraints imposed by this specification are set out in the normative schema Appendix A. To eliminate the potential for conflicts, this specification only describes syntax features that are not expressed in the normative schema.
This specification is a member of a suite of similar specifications that define specific types of tests that can be applied to the information contained on XBRL reports.
This specification builds on the foundation provided by the XBRL Variables specification [VARIABLES] .Although it does not depend on the XBRL Formulae specification [] it uses a similar processing model and shares most of its ideas
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.
The key words MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL, in this specification, are to be interpreted as described in [IETF RFC 2119].
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 |
---|---|
va
|
http://xbrl.org/2007/assertion/value
|
xbrlvae
|
http://xbrl.org/2007/assertion/value/error
|
eg
|
http://example.com/
|
fn
|
http://www.w3.org/2006/xpath-functions
|
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
|
variable
|
http://xbrl.org/2007/variable
|
iso4217
|
http://www.xbrl.org/2003/iso4217
|
validation
|
http://xbrl.org/2007/validation
|
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 value assertion is a statement meant to be tested on the results of the evaluation of a certain variable set, for a given XBRL instance. A data set for a value assertion is any of the evaluations of this variable set.
A value assertion is expressed by the
<va:value-assertion>
element
in the normative schema supplied with
this specification.
The assertion expression MAY have variable dependencies to parameters or to general or fact variables in the variable-set.
The following relationships defined in the Variables Specification [VARIABLES] MAY be used with value assertions:
A value assertion test is the effective Boolean value of the evaluation of its assertion expression. The context for this expression MUST:
<xbrli:xbrl>
element of the
target XBRL instance.
The evaluation of the variable set associated MUST consider any group filter or precondition associated to the assertion. The assertion expressions MAY include XPath variable references to any of the variables or parameters of its related variable set.
A value assertion MUST be associated to at least one fact variable.
[Error: Error code xbrlvae:emptyVariableSet MUST be thrown if the variable-set of the assertion doesn't include any fact variable. ]
Value assertions MAY produce one evaluation for each evaluation of its variable-set.
The prerequisite for the evaluation of this kind of assertions
is thus the evaluation of the variables in its
variable-set.
Given an evaluation of its variable-set,
the assertion evaluation entails evaluating the
XPath expression determined by the @test
attribute.
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/2007/
- 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/2007/value-assertion.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 |
---|---|---|
30 June 2007 | Geoff Shuetrim |
Initial draft created. |
22 July 2007 | Geoff Shuetrim |
Converted to XML format. |
15 October 2007 | Geoff Shuetrim |
Adapted to XBRLspec syntax. |
15 October 2007 | Geoff Shuetrim |
Adapted to XBRLspec syntax. |
20 November 2007 | Victor Morilla |
Created fact value assertions from validation report spec |
24 November 2007 | Victor Morilla |
Removed references to variable set resources |
06 December 2007 | Victor Morilla |
References to the definition of the assertion data set |
16 December 2007 | Victor Morilla |
Changed namespace of value assertions from http://xbrl.org/2007/value-assertion to http://xbrl.org/2007/assertion/value |
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 31 December 2007. 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.