Breaking out of loop in DFDL - dfdl

Question

I am trying to convert a FLAT file to XML using DFDL. It has following format:
Each element is 5 byte.All are in same line but i am separating them to avoid confusion. I will address element by first letter in them.
0AAAA
81AAA
eeeee
qqqqq
82BBB
rrrrr
sssss
9QQQQ
Now 0 and 9 are grandparents we don't have to worry about them. 8 is parent and second byte of 81AAA(that is 1) will determine the format of its children. There can be many 8 and many children of a 8 parent(but all of them will have same format).
I tried one schema but once it go into children(eeeee) its not coming out of it and every record is being printed in children format only.

Answer 1

Below is a schema that I think describes your data, tested on Daffodil 2.2.0:
<xs:schema
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:fn="http://www.w3.org/2005/xpath-functions"
xmlns:dfdl="http://www.ogf.org/dfdl/dfdl-1.0/">
<xs:include schemaLocation="org/apache/daffodil/xsd/DFDLGeneralFormat.dfdl.xsd" />
<xs:annotation>
<xs:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format ref="GeneralFormat" />
</xs:appinfo>
</xs:annotation>
<xs:element name="Root">
<xs:complexType>
<xs:sequence>
<xs:element name="GrandParent" maxOccurs="unbounded">
<xs:complexType>
<xs:choice dfdl:initiatedContent="yes">
<xs:element name="Zero" dfdl:initiator="0">
<xs:complexType>
<xs:sequence>
<xs:element name="Value" type="xs:string" dfdl:length="4" dfdl:lengthKind="explicit" />
<xs:element ref="Eight" minOccurs="0" maxOccurs="unbounded" />
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="Nine" dfdl:initiator="9">
<xs:complexType>
<xs:sequence>
<xs:element name="Value" type="xs:string" dfdl:length="4" dfdl:lengthKind="explicit" />
<xs:element ref="Eight" minOccurs="0" maxOccurs="unbounded" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="Eight" dfdl:initiator="8">
<xs:complexType>
<xs:sequence>
<xs:element name="ChildrenFormat" type="xs:string" dfdl:length="1" dfdl:lengthKind="explicit" />
<xs:element name="Value" type="xs:string" dfdl:length="3" dfdl:lengthKind="explicit" />
<xs:choice dfdl:choiceDispatchKey="{ ./ChildrenFormat }">
<xs:element ref="One" maxOccurs="unbounded" dfdl:choiceBranchKey="1" />
<xs:element ref="Two" maxOccurs="unbounded" dfdl:choiceBranchKey="2" />
</xs:choice>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="One" type="xs:string" dfdl:length="5" dfdl:lengthKind="explicit">
<xs:annotation>
<xs:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:discriminator test="{ fn:not(fn:starts-with(., '8') or fn:starts-with(., '9')) }" />
</xs:appinfo>
</xs:annotation>
</xs:element>
<xs:element name="Two" type="xs:string" dfdl:length="5" dfdl:lengthKind="explicit">
<xs:annotation>
<xs:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:discriminator test="{ fn:not(fn:starts-with(., '8') or fn:starts-with(., '9')) }" />
</xs:appinfo>
</xs:annotation>
</xs:element>
</xs:schema>
A description of how this works:
The Root of the data is an unbounded number of GrandParent elements
Each GrandParent element contains either a Zero or a Nine, based on the initiator. The initiator consumes the first of the 5 bytes of the grandparent data
The Zero/Nine elements contain a Value which consumes the remaining 4 bytes of the gradparent data
Following the Value is zero or more Eight elements
Each Eight element has an initiator of "8", consuming the first of 5 bytes
Each Eight element has a ChildrenFormat, consuming the second of 5 bytes
Each Eight element has a Value, consuming the last 3 of 5 bytes
Each Eight element has an unbounded number of either all One or all Two elements
A choiceDispatchKey/Branch is used to determine whether to parse all One or all Two elements, dispatching off of the ChildrenFormat element
Each One or Two element consumes 5 bytes
In order to determine when the unbounded number of One or Two elements ends, a discriminator is placed on the One/Two elements. This discriminator fails when the data parsed as a One/Two does not start with an '8' or a '9'.
Also, all fields are treated as strings for simplicity
With this, your example data parses to an infoset like so:
<Root>
<GrandParent>
<Zero>
<Value>AAAA</Value>
<Eight>
<ChildrenFormat>1</ChildrenFormat>
<Value>AAA</Value>
<One>eeeee</One>
<One>qqqqq</One>
</Eight>
<Eight>
<ChildrenFormat>2</ChildrenFormat>
<Value>BBB</Value>
<Two>rrrrr</Two>
<Two>sssss</Two>
</Eight>
</Zero>
</GrandParent>
<GrandParent>
<Nine>
<Value>QQQQ</Value>
</Nine>
</GrandParent>
</Root>