In general, the shape of the XML you get from dfdl is constrained by the format needs.
You dont generally get to decide what you want the XML to look like and then use dfdl to populate that. In that situation you really have two problems: 1) describe the structure of the physical data (as is) 2) describe how to map it to the structure you want instead. Dfdl is only about problem (1) above, and we have consciously tried not to turn it into a mapping language as for (2). Now, all that said, using hidden groups, dfdl:inputValueCalc and dfdl:outputValueCalc, you really can get it to do pretty complex mappings. Witness this example https://github.com/OpenDFDL/examples/tree/master/pairsTransform which converts data that is physically stored as a pair of lists into XML that is a list of pairs, effectively this is transposing a matrix. Another example is parsing IPv4 packets. If you want the IP addresses to show up in the XML as <src>1.2.3.4</src> then you have to create quite complex dfdl which is too complex to be considered declarative description. I consider this as a good example of what NOT to do in dfdl. See https://github.com/DFDLSchemas/ethernetIP/blob/master/src/main/resources/com/owlcyberdefense/dfdl/xsd/ipAddress.dfdl.xsd starting at line 56 to see what I mean. It is definitely possible to get dfdl to do this. It is just not recommended as a good practice. So philosophically, it can be helpful to think of dfdl as only being about describing the original data format. But .... one can do more transforming than this if you must. On Wed, Dec 1, 2021, 9:37 AM Nestor Fernandez < [email protected]> wrote: > Hi team, > > We have a requirement that some of the resulting XML elements after > parsing an EDIFACT file should be nested or wrapped by some grouping > element. > > Given an edi file with a flat structure like this: > > segment1 > segment2 > segment3 > segment4 > > our final goal would be to get an xml file with a more complex structure > such as this: > > <xml> > <segment1/> > <segment-wrapper> > <segment-wrapper> > <segment2/> > <segment3/> > </segment-wrapper> > <segment4/> > </segment-wrapper> > </xml> > > I know we could just use XSLT, but is it even possible just with Daffodil > libraries? I am new to DFDL, and thought this would be very simple, but all > things I tried have failed (either XSD is not valid, or I get daffodil > runtime errors). I am using apache-daffodil-3.1.0 command line interface. > > > I put together a more practical example: > > INPUT EDI file: > > HDR+1+0+59.97+64.92+4.95+Wed Nov 15 13?:45?:28 EST > 2006'CUS+user1+Harry:Fletcher+SD'ORD+1+1+364+The 40-Year-Old > Virgin+29.98'ORD+2+1+299+Pulp Fiction+29.99' > > > DFDL XSD Schema file: > > <?xml version="1.0" encoding="UTF-8" standalone="no"?> > <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"; xmlns:dfdl=" > http://www.ogf.org/dfdl/dfdl-1.0/"; xmlns:ibmEdiFmt=" > http://www.ibm.com/dfdl/EDI/Format";> > <xsd:import namespace="http://www.ibm.com/dfdl/EDI/Format"; > schemaLocation="IBM_EDI_Format.xsd"/> > <xsd:annotation> > <xsd:appinfo source="http://www.ogf.org/dfdl/";> > <dfdl:format ref="ibmEdiFmt:EDIFormat"/> > </xsd:appinfo> > </xsd:annotation> > <xsd:element name="Order"> > <xsd:complexType> > <xsd:sequence dfdl:initiatedContent="yes"> > <xsd:element dfdl:initiator="HDR" > dfdl:ref="ibmEdiFmt:EDISegmentFormat" name="header" type="HDR"/> > <xsd:element dfdl:initiator="CUS" > dfdl:ref="ibmEdiFmt:EDISegmentFormat" name="customer-details" type="CUS"/> > <xsd:element dfdl:initiator="ORD" > dfdl:ref="ibmEdiFmt:EDISegmentFormat" name="order-item" > maxOccurs="unbounded" type="ORD"/> > </xsd:sequence> > </xsd:complexType> > </xsd:element> > <xsd:complexType name="HDR"> > <xsd:sequence dfdl:ref="ibmEdiFmt:EDISegmentSequenceFormat"> > <xsd:element name="order-id" type="xsd:string"/> > <xsd:element name="status-code" type="xsd:string"/> > <xsd:element name="net-amount" type="xsd:string"/> > <xsd:element name="total-amount" type="xsd:string"/> > <xsd:element name="tax" type="xsd:string"/> > <xsd:element name="date" type="xsd:string"/> > </xsd:sequence> > </xsd:complexType> > <xsd:complexType name="CUS"> > <xsd:sequence dfdl:ref="ibmEdiFmt:EDISegmentSequenceFormat"> > <xsd:element name="username" type="xsd:string"/> > <xsd:element name="name"> > <xsd:complexType> > <xsd:sequence > dfdl:ref="ibmEdiFmt:EDICompositeSequenceFormat"> > <xsd:element name="firstname" type="xsd:string"/> > <xsd:element name="lastname" type="xsd:string"/> > </xsd:sequence> > </xsd:complexType> > </xsd:element> > <xsd:element name="state" type="xsd:string"/> > </xsd:sequence> > </xsd:complexType> > <xsd:complexType name="ORD"> > <xsd:sequence dfdl:ref="ibmEdiFmt:EDISegmentSequenceFormat"> > <xsd:element name="position" type="xsd:string"/> > <xsd:element name="quantity" type="xsd:string"/> > <xsd:element name="product-id" type="xsd:string"/> > <xsd:element name="title" type="xsd:string"/> > <xsd:element name="price" type="xsd:string"/> > </xsd:sequence> > </xsd:complexType> > </xsd:schema> > > > OUTPUT: > > <Order> > <header> > <order-id>1</order-id> > <status-code>0</status-code> > <net-amount>59.97</net-amount> > <total-amount>64.92</total-amount> > <tax>4.95</tax> > <date>Wed Nov 15 13:45:28 EST 2006</date> > </header> > <customer-details> > <username>user1</username> > <name> > <firstname>Harry</firstname> > <lastname>Fletcher</lastname> > </name> > <state>SD</state> > </customer-details> > <order-item> > <position>1</position> > <quantity>1</quantity> > <product-id>364</product-id> > <title>The 40-Year-Old Virgin</title> > <price>29.98</price> > </order-item> > <order-item> > <position>2</position> > <quantity>1</quantity> > <product-id>299</product-id> > <title>Pulp Fiction</title> > <price>29.99</price> > </order-item> > </Order> > > > Let's say we want to nest XML elements (originally EDI segments), header > and custom-details, and get something similar to this: > > EXAMPLE OF DESIRED OUTPUT: > > <Order> > <order-info> > <header> > <order-id>1</order-id> > <status-code>0</status-code> > <net-amount>59.97</net-amount> > <total-amount>64.92</total-amount> > <tax>4.95</tax> > <date>Wed Nov 15 13:45:28 EST 2006</date> > </header> > <customer-details> > <username>user1</username> > <name> > <firstname>Harry</firstname> > <lastname>Fletcher</lastname> > </name> > <state>SD</state> > </customer-details> > </order-info> > <order-item> > <position>1</position> > <quantity>1</quantity> > <product-id>364</product-id> > <title>The 40-Year-Old Virgin</title> > <price>29.98</price> > </order-item> > <order-item> > <position>2</position> > <quantity>1</quantity> > <product-id>299</product-id> > <title>Pulp Fiction</title> > <price>29.99</price> > </order-item> > </Order> > > > Any ideas would be appreciated. > > Thanks and regards >
