Hi:
Here's some comments on the SRU 2.0 Draft I just posted to the
<[log in to unmask]> feedback list. I am copying them
here for information and/or discussion.
Caveat: I recently joined up to the OASIS Search Web Services TC but these
comments represent my views before joining.
Cheers,
Tony
====
Hi:
Here's some initial feedback on the SRU 2.0 Draft.
Cheers,
Tony
#####
1. Parameters / Elements
I think it would help to break out Request Parameters from Response Elements
in Sects. 4, 6 and 7. The two sets are largely disjoint. (Same remark
applies to the Abstract Protocol Definition.)
Also might help to break out discussion of Facets into separate section (as
Diagnostics and Extensions), especially since Facets is an optional feature.
I also think that Search Result Analysis is sufficiently specialized to
warrant its own section.
Sect. 5 seems to be misplaced coming as it does in between Sect. 4 and
Sects. 6 and 7.
2. Parameter / Element Ordering
Not clear what the basis is for the orderings given in Sect. 2 (Table 1) and
3 (Table 6). Is it a logical ordering?
I note that "echoedSearchRetrieveRequest" is differently located (at bottom)
from its location in the 1.* XSD schema. Is that intentional?
<xsd:complexType name="searchRetrieveResponseType">
...
<xsd:sequence>
...
<xsd:element ref="echoedSearchRetrieveRequest" minOccurs="0"/>
<xsd:element ref="diagnostics" minOccurs="0"/>
<xsd:element ref="extraResponseData" minOccurs="0"/>
</xsd:sequence>
...
</xsd:complexType>
Also note that ordering is different in the tables and in Sect. 4.
3. Response Elements
Response elements are given for a specific serialization - XML.
Is that what is intended by binding? I would have thought binding would be
to a specific data model (e.g. SRU) which can then be serialized various
ways: native XML, ATOM, RSS, JSON, etc.
Thus don't see relevance of the angle brackets in Table 6. (And that does
also have a bearing on the type constraints that are offered if the elements
are not only XML.)
Also, heading in Sect. 3.1 is to "Actual Reponse Elements ..." and should be
"Reponse Elements ..." only. (Cf Sect. 2.1 which is to "Request Parameters
..." alone.)
4. Response Elements: "resultSetIdentifier", "timeToLive", "idleTime"
Mentioned in Sect 2, 3 and 4.10 the element "resultSetIdentifier" should be
"resultSetId" everywhere.
And in Sect 3, "timeToLive" and "idleTime" should be "resultSetTTL" and
"resultSetIdleTime", respectively.
5. Response Elements: "diagnostics"
Probably don't need the "(non-surrogate)" in the name value field. Perhaps
this could be footnoted in the table?
6. Request Parameters: "httpAccept-*"
I think these params are incorrectly named and should follow the standard
camelcase style used elsewhere. e.g.
Accept-Charset: httpAccept-charset -> httpAcceptCharset
Accept-Encoding: httpAccept-encoding -> httpAcceptEncoding
Accept-Language: httpAccept-language -> httpAcceptLanguage
Accept-Ranges: httpAccept-ranges -> httpAcceptRanges
Even though they mimic the HTTP headers they break naming convention.
7. Request Parameters: "rendering"
This is just a query. I wonder if the terms "client" / "server" would be
more appropriate than "local" / "remote". It might be more correct to talk
about "local" / "remote" but I always end up having to do a double take to
figure out my relative position.
8. Request Parameters: recordSchema, sortKeys/sortSchema
Both "recordSchema" and "SortKeys/sortSchema" allow for short names to be
used in place of URIs. But the SRU registered short names [1] are not
unique. E.g. "mods" is mapped to four different XML schema (3.0, 3.1, 3.2,
3.3) and likewise "pam" is ampped to two different XML schema (2.0, 2.1).
Also in Sect. 4.7.1 it says under sortSchema "the URI for an XML schema".
What is meant though is the "short name" for an XML schema, which is a
placeholder for the URI. And that is shown in the examples but needs better
explanation.
Still, the short name to URI mapping problem remains.
[1] http://www.loc.gov/standards/sru/resources/schemas.html
9. Response ID
There is no ID returned in the response. If there are records then a
"resultSetId" is returned but not otherwise. Some serializations (e.g. ATOM)
require an ID (actually a URI) for the response. One strategy would be to
use the "resulSetId" as the basis for a unique ID, but this fails when no
records are returned and a response is still required to carry the
diagnostics.
Is there some other place to return a unique response ID?
10. Endpoints
I would have preferred to see the "operation" parameter maintained so that
"searchRetrieve" and "scan" could both be located on the same endpoint, and
an explicit choice be made between them. Heuristics could be applied but I
think this is an unnecessary shorthand and may only lead to problems down
the line. I would have made this parameter optional at the least.
As regards version agree that it could be dispensed with although don;t see
any real harm in allowing for an optional parameter. Definitely not a
required parameter.
11. Typos, etc
a) Sects 2 and 3 (Tables 1 and 6)
Suggest that all categories which are not strict parameter names (e.g.
"Facet parameters", "Extension parameters", "Extension", etc.) be set in
italics to differentiate from actual parameter names.
And some tidying up of punctuation etc., e.g. No periods on "Reference" /
"Restrictions" columns (which by the way should both be the same head e.g.
"Reference"?). And perhaps "see" instead of "See", and "optionsl" nstead of
"Optional".
b) 4.7.1 "Sort Sub Parameters" and "sub parameters" in text
Preferably "sub-parameter" or "subparameter".
c) 4.7.2 "Textual Representation of sortKeys Parameter"
Maybe should just be something like "Represention of sortKeys Parameter
Value". Don't need the "Textual", and this is the parameter *value*, not the
parameter we're talking about.
d) 4.9.1
Should everywhere be "HTTP Accept header" (lowercase "header"), and
"Content-Location" (capitalized).
#####
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