1

XBRL Formula Linkbase Introduction

SDMX TWG (4th meeting in Paris OECD)

Paris,14.12.2012

Wojciech Ciebiera

2

XBRL Linkbases

Paris,14.12.2012

Current:• Label Linkbase (Readable form of concept, languages)• Reference Linkbase (Regulations)• Calculation Linkbase (Simple summing)• Definition Linkbase (Relations between elements: dimensions, measures)• Presentation Linkbase (Not visual form! Rather order of elements)New:• Formula Linkbase (Assertions)• Rendering Linkbase (Visual form)

*Formula Linkbase is currently used in NBP Supervisory Statistics

3

SDMX vs. XBRL (XML schema structure)

Paris,14.12.2012

xs:s

chem

a

namespaces

Import/include

element

element

element

element

element

element

element

elementelement

xs:s

chem

a

namespaces

Import/include

element

element

element

element

element

element

element

element

SDMX schema XBRL schema

namespaces

Import/include

element

element

element

namespaces

Import/include

element

element

element

Linkbases

Label Linkbase

Formula Linkbase

xs:s

chem

a

namespaces

Import/include

element

element

element

element

element

element

element

elementelement

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SDMX vs. XBRL (XML instance structure)

Paris,14.12.2012

root

namespaces

Import/include

element

element

element

elementelement

elementelement

element

root

namespaces

Import/include

element

element

element

element

element

element

element

<xbrli:context id=„@id">(ns:dimensions)

<ns:element contextRef=„@id">(unitRef,decimals)

SDMX instance XBRL instance

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Profit = (1*Revenue) + (-1*Costs)<calculationArc xlink:type="arc" link:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Profit" xlink:to="Revenue" order="1" weight="1" use="optional"/> <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Profit" xlink:to="Costs" order="2" weight="-1" use="optional"/>

*attribute weight is of type „xs:decimal”

Older Calculation Linkbase (summation)

Paris,14.12.2012

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Formula Linkbase functionality

Paris,14.12.2012

• Contain: Nodes, values, elements• General comparison: =, !=, <>• Values comparison: eq, ne, lt, le, gt, ge• Structures: if than else• Iterators: for• Aggregations: max(), min(), avg()• Cross-dependencies (i.e. in one file several reporters)• Thresholds• Local functions (local:function)• Predefined XBRL Functions 1.0

– xfi:period– xfi:entity– xfi:segment

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Formula Linkbase (technologies)

Paris,14.12.2012

XQuery

XSLT

XLink

XPath

XPointerUsed in Formula Linkbase• XQuery• XPointer• XPath• XLink

Used in SDMX ExpressionsAnd Calculations• ?

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XQuery FLWOR: FOR

Paris,14.12.2012

XQuery (FLWOR construction: For, Let, Where, Order, Return).

File.xml:<root> <element> <entry1>10</entry1> <entry2>OECD</entry2> </element> <element> <entry1>110</entry1> <entry2>NBP</entry2> </element> </root>

FOR code:for $item in doc('File.xml')/root/elementwhere $item/entry1>50return $item/entry2

FOR result:<?xml version='1.0' encoding='UTF-8'?><entry2>NBP</entry2>

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XQuery FLWOR: LET, WHERE, ORDER, RETURN

Paris,14.12.2012

LET code:let $item :=(1 to 5) return<element>{$item}</element>LET result:<element>1 2 3 4 5</element>

WHERE code:for $item in (1 to 5) where $item = 3return<element>{$item}</element>WHERE result:<element>3</element>

ORDER code:Let $item in ('Xavier','Wojciech','Jens','Chris')Order by $item return<name>{$item}</name>ORDER result:<name>Chris</name><name>Jens</name><name>Wojciech</name><name>Xavier</name>

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Types of assertions

Paris,14.12.2012

Formula validation:• Consistency assertion

– Precalculated values compared to real economic facts• Value assertion

– Math equations• Existence assertion

– Checking if the value is mandatory

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Value Assertion (example)

Paris,14.12.2012

This is validation of PESEL ID (used in Poland):

<va:valueAssertion xlink:type="resource" xlink:label="valueAssertion" xlink:title="valueAssertion" id="valueAssertion" test="for $v in $v1 return (string-length($v) = 11 and matches($v, '^[0-9]{11}') and sum( for $i in 1 to 11 return (1,3,7,9,1,3,7,9,1,3,1)[$i] * number( substring( $v, $i, 1) ) ) mod 10 eq 0 )" aspectModel="dimensional" implicitFiltering="true"/><variable:generalVariable xlink:type="resource" xlink:label="generalVariable" xlink:title="generalVariable" id="UnitCode" select="//d-LE:UnitCode" bindAsSequence="false"/> <variable:variableArc xlink:type="arc" xlink:arcrole="http://xbrl.org/arcrole/2008/variable-set" xlink:from="valueAssertion" xlink:to="generalVariable" xlink:title="valueAssertion to generalVariable" priority="0" order="1.0" name="v1"/>

*Formula Linkbase is descriptive language rather than sequence code. Tests return value true or false.

12

Fujitsu Formula Editor for Formula Linkbase

Paris,14.12.2012

13

Current NBP Solution (Balance of Payment)

Paris,14.12.2012

XQuery

XSLT

XLink

XPath

XPointer

Solution used in NBP• Adobe LiveCycle• XSD• XSLT• XPath

XML FILE

PDF

XSDValidation XSLT

Validation

Sche

ma

Erro

r

Cal

cula

tion

Erro

r

14

Paris,14.12.2012

Thank you for you attention!

Questions?

Wojciech CiebieraEconomic ExpertDepartment of StatisticsNational Bank of Poland