Skip 2007 Current Issues in MIS The XML Language Foundation f - Clinton E. White, Jr Professor of Accounting & MIS Lerner College of B&E University of Delaware

Skip 2007 Current Issues in MIS The XML Foundation Many participants – an extended family! Many participants – an extended family! – XML documents – carry data in context Each must be parsed into its component parts Each must be parsed into its component parts – XML schemas – define the rules a class of documents must follow Can be used to validate documents & contents Can be used to validate documents & contents – XSLT – provide processing instructions Can be used to process XML documents Can be used to process XML documents – Namespaces – qualify elements & attributes Differentiate & associate them with a URI Differentiate & associate them with a URI – XPath … XLink … XQuery … XML Processors are not designed equally! XML Processors are not designed equally!

Skip 2007 Current Issues in MIS Simple Elements Simple XML elements can contain only data values Simple XML elements can contain only data values – In an XML document: Basketball Basketball – In an XML schema:

Skip 2007 Current Issues in MIS Complex Elements Complex XML elements contain other elements nested within them and/or contain attributes Complex XML elements contain other elements nested within them and/or contain attributes – In an XML document Basketball Basketball

Skip 2007 Current Issues in MIS Complex Elements In an XML schema: In an XML schema: <xs:element name="InventoryItem" minOccurs="1" <xs:element name="InventoryItem" minOccurs="1" maxOccurs="unbounded"> maxOccurs="unbounded">

Skip 2007 Current Issues in MIS Simple Element with an Attribute (complex element) A simple element with an attribute is a complex element (but with simple content) A simple element with an attribute is a complex element (but with simple content) – In an XML document Regulation NBA Regulation NBA – In an XML schema

Skip 2007 Current Issues in MIS

Skip 2007 Current Issues in MIS Validation Validated & ready for further processing Validated & ready for further processing XML Document XML schema document Validating XML Processor Validated XML Document

Skip 2007 Current Issues in MIS XML Namespaces (xmlns) XML Namespaces: XML Namespaces: – A collection of elements and attributes for a particular purpose Each XML namespace has a unique URI Each XML namespace has a unique URI Each namespace is declared using “xmlns” Each namespace is declared using “xmlns” – xmlns:xs=" – xmlns:us-gaap-ci =" ci/ /us-gaap-ci%20Summary%20Page.htm“ Each namespace has its own recommended prefix Each namespace has its own recommended prefix

Skip 2007 Current Issues in MIS Namespaces Namespaces solve the naming collision problem! Namespaces solve the naming collision problem! – What if within your company, you have an accounting department & a shipping department and they each want to use the XML element name “status” to mean things uniquely relevant to them? In accounting, status is used to mean billed or not! In accounting, status is used to mean billed or not! In shipping, status is used to mean shipped or not! In shipping, status is used to mean shipped or not!

Skip 2007 Current Issues in MIS Namespaces The solution The solution – Create a separate namespace for each department & within each namespace, define the element name “status” Accounting’s namespace: Accounting’s namespace: – xmlns:acct=“myCompany.com/xml/accounting” Shipping’s namespace: Shipping’s namespace: – xmlns:ship=“myCompany.com/xml/shipping”

Skip 2007 Current Issues in MIS Namespaces Within the myCompany.com/xml/accounting namespace Within the myCompany.com/xml/accounting namespace Within the myCompany.com/xml/shipping namespace Within the myCompany.com/xml/shipping namespace

Skip 2007 Current Issues in MIS Sales Order Status Report <SalesOrderStatus <SalesOrderStatus xmlns:ship=" xmlns:ship=" xmlns:acct=" xmlns:acct=" shipped shipped not billed not billed

Skip 2007 Current Issues in MIS XLink XLink – the XML linking language XLink – the XML linking language – An “attribute” language to be used in XML documents to define explicit relationships between resources – XLink attributes can be used on any XML element – XLink attributes are used to describe both “simple” and “extended” relationships

Skip 2007 Current Issues in MIS A Simple Link What if you wanted to define a link between an InventoryItem and an approved list of vendors? What if you wanted to define a link between an InventoryItem and an approved list of vendors? – – – A “simple” XLink creates a unidirectional link between an element and the document (resource) found at the referenced URI

Skip 2007 Current Issues in MIS An Extended Link What if you wanted to create a report to be used to reconcile a PO, receiving report, and voucher from a vendor? What if you wanted to create a report to be used to reconcile a PO, receiving report, and voucher from a vendor? – – – <PurchaseOrder id=“12345” xlink:type=“locator” – xlink:href= “ – <ReceivingReport id=“34567” xlink:type=“locator” – xlink:href= “ – <Voucher id=“456789” xlink:type=“locator” – xlink:href= “ – – – Extended links are used to create more complex relationships between resources As in financial statements! As in financial statements!

Skip 2007 Current Issues in MIS XBRL XLink is used in the XBRL vocabulary to create “linkbases” XLink is used in the XBRL vocabulary to create “linkbases” – XBRL linkbases are databases of extended links to define accounting concepts and their relationships How is “current assets” calculated? How is “current assets” calculated? How is it presented on a balance sheet? How is it presented on a balance sheet? What official references apply? What official references apply?

Skip 2007 Current Issues in MIS Assignment Assignment due: 10/4/2007 Assignment due: 10/4/2007 – Exercise 3-1