DataLink version 1.0 Proposed Erratum 4: Self-Describing Service example fix

Author: Mark Taylor, François Bonnarel

Date last changed: 2020-05-11

Date accepted: 2020-06-11

Rationale

In the process of moving the DataLink-1.0 into the ivoa-std GitHub repo, it has been found an error in the example in §4.6 (page 26) (see DataLink issue #3). The error consists in a wrong ref="primaryID" attribute linking a service descriptor PARAM to a results table FIELD. This erratum proposes to suppress the wrong ref attribute.

Erratum Content

This Erratum proposes to replace, in §4.6 of DataLink - Version 1.0 the first RESOURCE element of the example:

<RESOURCE type=”meta” utype=”adhoc:service” name=”this”>
   <PARAM name="standardID" datatype="char" arraysize="*"
      value="ivo://ivoa.net/std/DataLink#links-1.0" />
   <PARAM name="accessURL" datatype="char" arraysize="*"
      value="http://example.com/mylinks" />
   <GROUP name=”inputParams”>
      <PARAM name=”ID” datatype=”char” arraysize=”*”
         value=”” ref=”primaryID”/>
   </GROUP>
</RESOURCE>

with the following one:

<RESOURCE type=”meta” utype=”adhoc:service” name=”this”>
   <PARAM name="standardID" datatype="char" arraysize="*"
      value="ivo://ivoa.net/std/DataLink#links-1.0" />
   <PARAM name="accessURL" datatype="char" arraysize="*"
      value="http://example.com/mylinks" />
   <GROUP name=”inputParams”>
      <PARAM name=”ID” datatype=”char” arraysize=”*” value=”” />
   </GROUP>
</RESOURCE>

That is, removing the ref attribute and its value, that refer to a non-existent FIELD in the example itself.

Impact Assessment

The proposed change doesn't impact any part of DataLink implementations since it simply amends an example fixing it.