There is no way to vary the pattern depending
on the value of a variable unless you have a limited number of possible
patterns. In that case you could use the variable ( in the expression
for a DFDL discriminator ) to discriminate a choice where each branch of
the choice has a different DFDL regular expression.
However, I think you need more flexibility
than that - the boundary string could be just about anything, right?. The
dfdl:initiator/separator/terminator properties do take a DFDL expression,
and it should be possible to model a wide range of data formats using those
properties. Is there some reason why that is not possible in your case?
regards,
Tim Kimber, DFDL Team,
Hursley, UK
Internet: kimbert@uk.ibm.com
Tel. 01962-816742
Internal tel. 37246742
From:
"Garriss Jr.,
James P." <jgarriss@mitre.org>
To:
"dfdl-wg@ogf.org"
<dfdl-wg@ogf.org>,
Date:
25/06/2013 12:38
Subject:
Re: [DFDL-WG]
Can I concatenate a variable?
Sent by:
dfdl-wg-bounces@ogf.org
> In section 12.3.5 of
the specification, the 'lengthPattern' property is listed as having the
type 'DFDL Regular expression'. Unlike some other properties, dfdl:lengthPattern
cannot be a DFDL expression. Therefore it cannot contain a DFDL variable
reference.
Is there no workaround for
this?
From: dfdl-wg-bounces@ogf.org [mailto:dfdl-wg-bounces@ogf.org]
On Behalf Of Tim Kimber
Sent: Monday, June 24, 2013 4:11 PM
To: dfdl-wg@ogf.org
Subject: Re: [DFDL-WG] Can I concatenate a variable?
Hi James,
In section 12.3.5 of the specification, the 'lengthPattern' property is
listed as having the type 'DFDL Regular expression'. Unlike some other
properties, dfdl:lengthPattern cannot be a DFDL expression. Therefore it
cannot contain a DFDL variable reference.
On the other hand, section 14.2 lists the data type of dfdl:separator as
'List of DFDL String Literals or DFDL Expression', However, your dfdl:separator
is not a valid DFDL expression. The property must be either a valid DFDL
expression or a list of DFDL string literals. The syntax you need is
<xsd:sequence
dfdl:separator="{fn:concat('--'),$some_boundary}"
dfdl:separatorSuppressionPolicy="anyEmpty"
dfdl:terminator="--%CR;%LF;">
regards,
Tim Kimber, DFDL Team,
Hursley, UK
Internet: kimbert@uk.ibm.com
Tel. 01962-816742
Internal tel. 37246742
From: "Garriss
Jr., James P." <jgarriss@mitre.org>
To: "dfdl-wg@ogf.org"
<dfdl-wg@ogf.org>,
Date: 24/06/2013
20:38
Subject: [DFDL-WG]
Can I concatenate a variable?
Sent by: dfdl-wg-bounces@ogf.org
Suppose I define a variable like this:
<dfdl:defineVariable
name="boundary"
defaultValue="some_boundary"
type="xsd:string"/>
Can I later concatenate it with other values?
For example, can I concatenate it as part of a pattern?
<xsd:element
name="Preamble"
type="xsd:string"
dfdl:lengthKind="pattern"
dfdl:lengthPattern="(.+?)(?=--{$some_boundary})"/>
Can I concatenate it as part of a separator?
<xsd:sequence
dfdl:separator="--{$some_boundary}"
dfdl:separatorSuppressionPolicy="anyEmpty"
dfdl:terminator="--%CR;%LF;">
TIA!--
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Unless stated otherwise above:
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741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6
3AU