Copyright © Open Applications Group, Inc. All rights reserved 1 OAGi XML Schema User Report June 21, Michael Rowell Chief Architect Open Applications Group, Inc.

Copyright © Open Applications Group, Inc. All rights reserved 2 Not-For-Profit Industry Consortium to: Promote interoperability among Business Software Applications and To create and/or endorse one or more standards for easier business software interoperability Open Applications Group Who we are

Copyright © Open Applications Group, Inc. All rights reserved 3 Open Applications Group OAGi is... The Open Applications Group, Incorporated OAGIS is... The Open Applications Group Integration Standard

Copyright © Open Applications Group, Inc. All rights reserved 4 OAGi and OAGIS OAGi uses XML Schema to define an instantiation of OAGIS XML Schema is used to validate runtime XML Instances. OAGIS is defined to address needs of common message communications. –For example there are only so many ways to do a PurchaseOrder. –Why reinvent it each time? OAGIS 9.0 includes 434 Business Object Documents (BODs)

Copyright © Open Applications Group, Inc. All rights reserved 5 Extensions OAGi recognizes the need for extensions and change. –The one constant is change. OAGi has designed OAGIS to be extensible.

Copyright © Open Applications Group, Inc. All rights reserved 6 Solution Provider specific Overlay Vertical Content Overlay Vertical Content Overlay Vertical Content Overlay Company Specific Overlay OAGIS Supports Vertical “Plug-Ins” OAGIS Canonical Business Language CRM ERP Customer Supplier OAGIS is Horizontal Content

Copyright © Open Applications Group, Inc. All rights reserved 7 Discussion

Copyright © Open Applications Group, Inc. All rights reserved 8 Extensible Schema XML Schema includes three means to implement extension –Xsi:type –Any –Extend and Substitute Type derivation by extension SubstitutionGroups

Copyright © Open Applications Group, Inc. All rights reserved 9 Elements The debate over global vs. local elements continues… –Each has their strengths and weaknesses

Copyright © Open Applications Group, Inc. All rights reserved 10 Substitution Groups Recommendation –Substitution groups for local elements Would allow local elements to be substituted for within the scope of their definitions. This would help to apply context specific meaning to a given element

Copyright © Open Applications Group, Inc. All rights reserved 11 complexType Derivation by Restriction As it currently is defined simply makes a copy of the base type and the author further restricts the definition. –There is no inheritance from the base type, should it change –Is not allowed across namespaces This prohibits a user to embrace and add restrictions to a standard for their own needs.

Copyright © Open Applications Group, Inc. All rights reserved 12 schemaLocation Constancy When used in: –An instance the xsi:schemaLocation the recommendation indicates that the location is a hint from the author as to where the xsd definition can be found, additionally the attribute is optional. –An include the attribute is required and this time it must reference an xsd document. –An import the attribute is optional, again if present it is a hint as to where to find the given xsd document.

Copyright © Open Applications Group, Inc. All rights reserved 13 schemaLocation Should be constantly defined Using schemaLocation in our view should be definitive. When used the definition should be resolvable at the given location.

Copyright © Open Applications Group, Inc. All rights reserved 14 Redefine Redefines do not work across namespaces, so only the schema author can redefine. –Our experience says that things defined should remain consistently defined within their scope. –While local elements may be defined differently depending upon their scope. –If redefines were allowed across namespaces it would be possible for a schema to be further defined by users other that the author. We see derivation by restriction as more important to this. –Typically, certain types need to be restricted not generally entire file modules.

Copyright © Open Applications Group, Inc. All rights reserved 15 Model Group All Treating a collection of elements within a parent as bag without any particular order is really makes sense. –However the implied sequence when inheriting from base type make this difficult. It is not possible to mix the bags of elements. –Being able to set the inheritance model group would resolve this. By enabling a bag of bags.

Copyright © Open Applications Group, Inc. All rights reserved 16 simpleType Union This is more of an issue with implementation support.

Copyright © Open Applications Group, Inc. All rights reserved 17 A Q & Q U E S T I O N S A N S W E R S

Copyright © Open Applications Group, Inc. All rights reserved 18 Michael Rowell Open Applications Group Chief Architect