xbrl formula linkbase introduction

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XBRL Formula Linkbase Introduction

SDMX TWG (4th meeting in Paris OECD)

Paris,14.12.2012

Wojciech Ciebiera

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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

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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.

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Fujitsu Formula Editor for Formula Linkbase

Paris,14.12.2012

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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

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Paris,14.12.2012

Thank you for you attention!

Questions?

Wojciech CiebieraEconomic ExpertDepartment of StatisticsNational Bank of Poland