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Message
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| mrk.for.dev |
 Posted: Mon Jan 11, 2021 5:45 am Post subject: Create new Object from XSD in ESQL |
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Novice
Joined: 11 Jan 2021
Posts: 23
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Is there a way to create an object whose format is defined in a message model?
Actually, I have created a message model with some fields containing default values and some restrictions. I managed with the following code to create a message in ESQL, but the other fields (which contain default values) do not appear :
| Code: |
CREATE LASTCHILD OF OutputRoot DOMAIN('DFDL');
-- SET OutputRoot.Properties = InputRoot.Properties;
SET OutputRoot.Properties.MessageSet = '{ObjectsDefinitionLibrary}';
SET OutputRoot.Properties.MessageType = '{}:Example1MsgModel';
SET OutputRoot.DFDL.Example1MsgModel.record[1].FieldOne = 'Value1'; |
Will this be possible with ESQL? |
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| Vitor |
| Posted: Mon Jan 11, 2021 7:33 am Post subject: Re: Create new Object from XSD in ESQL |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| mrk.for.dev wrote: |
| I managed with the following code to create a message in ESQL, but the other fields (which contain default values) do not appear : |
Do not appear where? The DFDL defaults probably don't show up in a trace or the debugger because they're used as part of the serialization process. They should therefore show up in the final written record.
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| mrk.for.dev |
| Posted: Mon Jan 11, 2021 7:55 am Post subject: |
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Novice
Joined: 11 Jan 2021
Posts: 23
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| The default fields are not visible either in the debugger or in the final output (to a file). |
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| Vitor |
| Posted: Mon Jan 11, 2021 8:11 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| mrk.for.dev wrote: |
| The default fields are not visible either in the debugger or in the final output (to a file). |
Post your DFDL
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| mrk.for.dev |
| Posted: Mon Jan 11, 2021 8:55 am Post subject: |
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Novice
Joined: 11 Jan 2021
Posts: 23
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Here is the DFDL :
| Code: |
<?xml version="1.0" encoding="UTF-8"?><xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:csv="http://www.ibm.com/dfdl/CommaSeparatedFormat" xmlns:dfdl="http://www.ogf.org/dfdl/dfdl-1.0/" xmlns:fn="http://www.w3.org/2005/xpath-functions" xmlns:ibmDfdlExtn="http://www.ibm.com/dfdl/extensions" xmlns:ibmSchExtn="http://www.ibm.com/schema/extensions">
<xsd:import namespace="http://www.ibm.com/dfdl/CommaSeparatedFormat" schemaLocation="IBMdefined/CommaSeparatedFormat.xsd"/>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format documentFinalTerminatorCanBeMissing="yes" encoding="{$dfdl:encoding}" escapeSchemeRef="csv:CSVEscapeScheme" ref="csv:CommaSeparatedFormat"/>
</xsd:appinfo>
</xsd:annotation>
<xsd:element ibmSchExtn:docRoot="true" name="Example1MsgModel">
<xsd:complexType>
<xsd:sequence dfdl:separator="">
<xsd:element dfdl:terminator="%CR;%LF;%WSP*;" name="record">
<xsd:complexType>
<xsd:sequence dfdl:separator="|" dfdl:separatorSuppressionPolicy="trailingEmpty">
<xsd:element ibmDfdlExtn:sampleValue="value1" minOccurs="0" name="FieldOne" type="xsd:string"/>
<xsd:element default="FIXED_VALUE" ibmDfdlExtn:sampleValue="value2" minOccurs="0" name="FieldTwo" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:schema> |
[/code]
Here is the ESQL :
| Code: |
CREATE LASTCHILD OF OutputRoot DOMAIN('DFDL');
SET OutputRoot.Properties.MessageSet = '{ObjectsDefinitionLibrary}';
SET OutputRoot.Properties.MessageType = '{}:Example1MsgModel';
SET OutputRoot.DFDL.Example1MsgModel.record[1].FieldOne = 'AFFL02';
DECLARE refInput REFERENCE TO InputRoot.DFDL.Exemple1EntrantMsg.record[1];
DECLARE refOutput REFERENCE TO OutputRoot.DFDL.Example1MsgModel.record[1];
-- field 1
SET refOutput.FieldOne = 'AFFL02'; |
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| Vitor |
| Posted: Mon Jan 11, 2021 12:19 pm Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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The elements are set to minOccurs=0, so if no value is provided to the model it doesn't serialize the element and is content it has done right.
If you set minOccurs=1 (indicating that the element must be present in the serialized file) and don't provide a value, then the model will ensure you get the element you insisted on by using a default.
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| timber |
| Posted: Mon Jan 11, 2021 3:54 pm Post subject: |
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Grand Master
Joined: 25 Aug 2015
Posts: 1292
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| Quote: |
| Is there a way to create an object whose format is defined in a message model |
You need to define what you mean by 'object'. Do you want to create a message tree based on the model? Or do you want to generate a valid BLOB from the model?
As has been said by others, if you want to generate a BLOB from a DFDL model, you must ensure that everything in the message model (including complex elements) has minOccurs>=1, and you must provide a default value for every field.
If you want a message tree, you will need to parse that BLOB using the DFDL parser. Which leads nicely into the answer to your other question...
| Quote: |
| Will this be possible with ESQL? |
ESQL does not offer a special statement to create a message tree from a model. However, it does offer two functions for parsing and writing any BLOB/message tree. Look up the ASBITSTREAM function, and the CREATE function (with the PARSE clause). |
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| mrk.for.dev |
| Posted: Tue Jan 12, 2021 12:16 am Post subject: |
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Novice
Joined: 11 Jan 2021
Posts: 23
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Indeed, when minOccurs is set to 1, the values reappear in the output file (not in the debugger).
The original goal was to replace the Mapping node by a Compute node that transforms a Message Model to a different one. With the Mapping node it is obvious, but with the Compute node you have to create this message from the Message Model with ESQL.
Thank you  |
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| Vitor |
| Posted: Tue Jan 12, 2021 6:20 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| mrk.for.dev wrote: |
| Indeed, when minOccurs is set to 1, the values reappear in the output file (not in the debugger). |
Because it's not until you actually ask the model to be serialized the lack of the element is a problem. That minOccurs=1 doesn't apply to the message tree (for good and sufficient reason)
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