I would suggest this sort of thing.
<xs:choice>
<xs:sequence>
<xs:element name="uri" type="tns:upaDummy"/>
<xs:element name="name" type="tns:nameType" dfdl:terminator=":>" />
<xs:element name="value" type="tns:URLType" dfdl:terminator="%NL;" />
</xs:sequence>
<xs:sequence>
<xs:element name="b64" type="tns:upaDummy"/>
<xs:element name="name" type="tns:nameType" dfdl:terminator="::"/>
<xs:element name="value" type="tns:Base64Type"
dfdl:terminator="... whatever defines end of
base64 ..."/>
</xs:sequence>
<xs:sequence>
<xs:element name="str" type="tns:upaDummy"/>
<xs:element name="name" type="tns:nameType" dfdl:terminator=":">
<xs:element name="value" type="xs:string" dfdl:terminator="%NL;"/>
</xs:sequence>
</xs:choice>
The uri, b64, and str are flag UPA dummy elements which are unfortunately
unavoidable due to XSD restrictions.
The type upaDummy should define them to be fixed length zero-length strings.
Conversion of separators to terminators here is not arbitrary. When parsing a
base64, the above will work even if "::" was legal base64 syntax, because
there's no separator in scope surrounding the base64 value element.
...mike beckerle
Tresys
________________________________
From: Costello, Roger L. <[email protected]>
Sent: Monday, March 26, 2018 11:05:18 AM
To: [email protected]
Subject: RE: How to parse a line that is delimited by a colon but sometimes has
two colons?
I would like to generalize my question a bit.
Not only can there be two consecutive colons:
name:: value
(the second colon indicates the value is base64 text)
But there can be colons within value, e.g.
name:> file:///usr/local/directory/photos/fiona.jpg
(the > symbol indicates the value is a url, and the url may contain a colon)
So, how to express this in DFDL?
/Roger
-----Original Message-----
From: Costello, Roger L.
Sent: Monday, March 26, 2018 10:42 AM
To: [email protected]
Subject: How to parse a line that is delimited by a colon but sometimes has two
colons?
Hello DFDL experts!
I am using DFDL to parse lines that look like this:
name: value
I am using this DFDL code to parse the lines:
<xs:sequence dfdl:separator=":" dfdl:separatorPosition="infix">
<xs:element name="name" type="xs:string" />
<xs:element name="value" type="xs:string" /> </xs:sequence>
If the value is base64 text, then a double colon is used:
name:: base64-value
The above DFDL code doesn't seem to work in this situation. What's the correct
way to write DFDL code which can handle lines with a single colon as well as
lines with a double colon?
/Roger
