Using yaz_present to display subsets of results

Hello,

I have been unable to figure out how to use the
yaz_present() function 
to return subsets of my entire result set. I couldn't find a
functional 
example anywhere (inc. the PHP docs and the yaz mailing list
archives) 
so was hoping someone can tell me what I'm doing wrong.

In the following example, changing the value of $start has
no effect on 
the records returned by by my search:

$start = '1';
$number = '5';
$query = 'attr 1=4 test';
$id = yaz_connect('troy.lib.sfu.ca:210/innopac');
yaz_range($id, $start, $number);
yaz_syntax($id, 'marc21');
yaz_search($id, 'rpn', $query);
yaz_present($id);
yaz_wait();

// Formatting of results using XSL omitted


Number of records found: 1578
=============================
The biplane houses :poems /by Les Murray.
Embedded system design /by Peter Marwedel.
Hardening Windows systems /Roberta Bragg.
Java 2 :the complete reference /Patrick Naughton, Herbert
Schildt.
Practical MMIC design /Steve Marsh.


Since yaz_present() only takes the resource ID as a
parameter, and only 
returns TRUE or FALSE, I'm not sure how else it would be
used to produce 
results. The docs are sparse on this topic.

Any pointers to complete examples, or to what I am doing
wrong, would be 
appreciated. I'd be happy to post my complete script when it
is working.

Mark

Mark Jordan
Head of Library Systems
W.A.C. Bennett Library, Simon Fraser University
Burnaby, British Columbia, V5A 1S6, Canada
Phone (604) 291 5753 / Fax (604) 291 3023
mjordansfu.ca / http://www.sfu.ca/~mjorda
n/

_______________________________________________
Yazlist mailing list
Yazlistlists.indexdata.dk
http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list

Mark Jordan wrote:
> Hello,
> 
> I have been unable to figure out how to use the
yaz_present() function 
> to return subsets of my entire result set. I couldn't
find a functional 
> example anywhere (inc. the PHP docs and the yaz mailing
list archives) 
> so was hoping someone can tell me what I'm doing wrong.
> 
> In the following example, changing the value of $start
has no effect on 
> the records returned by by my search:
> 
> $start = '1';
> $number = '5';
> $query = 'attr 1=4 test';
> $id = yaz_connect('troy.lib.sfu.ca:210/innopac');
> yaz_range($id, $start, $number);
> yaz_syntax($id, 'marc21');

Use
  yaz_syntax($id, "usmarc");
instead.
> yaz_search($id, 'rpn', $query);
> yaz_present($id);
It should not be necessary to use yaz_present. (yaz_search
will get the 
range).

/ Adam

> yaz_wait();
> 
> // Formatting of results using XSL omitted
> 
> 
> Number of records found: 1578
> =============================
> The biplane houses :poems /by Les Murray.
> Embedded system design /by Peter Marwedel.
> Hardening Windows systems /Roberta Bragg.
> Java 2 :the complete reference /Patrick Naughton,
Herbert Schildt.
> Practical MMIC design /Steve Marsh.
> 
> 
> Since yaz_present() only takes the resource ID as a
parameter, and only 
> returns TRUE or FALSE, I'm not sure how else it would
be used to produce 
> results. The docs are sparse on this topic.
> 
> Any pointers to complete examples, or to what I am
doing wrong, would be 
> appreciated. I'd be happy to post my complete script
when it is working.
> 
> Mark
> 
> Mark Jordan
> Head of Library Systems
> W.A.C. Bennett Library, Simon Fraser University
> Burnaby, British Columbia, V5A 1S6, Canada
> Phone (604) 291 5753 / Fax (604) 291 3023
> mjordansfu.ca / http://www.sfu.ca/~mjorda
n/
> 
> _______________________________________________
> Yazlist mailing list
> Yazlistlists.indexdata.dk
> http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list
> 
> 


_______________________________________________
Yazlist mailing list
Yazlistlists.indexdata.dk
http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list

Hi Adam,

I'm still missing something. Using yaz_syntax($id,
"usmarc") doesn't 
make a difference. Here's my entire script (with record
formatting 
removed -- it just prints records as XML):

<?php

$max_recs = 5;
$query = $argv[1];
$field = $argv[2];
$start_at_rec = $argv[3];
$query = trim($query);
$field = trim($field);

$fields = array('title' => '4', 'author' => '1003',
'subject' => '21');

$query = 'attr 1=' . $fields[$field] . ' ' . $query;
print "Query is $queryn";
print "Starting at record $start_at_recn";

$id = yaz_connect('troy.lib.sfu.ca:210/innopac');
yaz_range($id, $start_at_rec, $max_recs);
yaz_syntax($id, "usmarc");
yaz_search($id, 'rpn', $query);
yaz_wait();

$error = yaz_error($id);
if (!empty($error)) {
   echo "Error: $error";
   print "n";
   exit;
} else {
   $hits = yaz_hits($id);
   if ($hits == '0') {
     print "No hitsn";
     exit;
   }
}

for ($p = 1; $p <= $max_recs; $p++) {
   $rec = yaz_record($id, $p, "xml; marc-8,
utf-8");
   if (empty($rec)) continue;
   print $rec;
}

?>

BTW I'm using PHP/YAZ version  1.0.7, YAZ version 2.1.36,
PHP 5.1.6 on 
FedoraCore 5/ppc.

Mark

Adam Dickmeiss wrote:
> Mark Jordan wrote:
>> Hello,
>>
>> I have been unable to figure out how to use the
yaz_present() function 
>> to return subsets of my entire result set. I
couldn't find a 
>> functional example anywhere (inc. the PHP docs and
the yaz mailing 
>> list archives) so was hoping someone can tell me
what I'm doing wrong.
>>
>> In the following example, changing the value of
$start has no effect 
>> on the records returned by by my search:
>>
>> $start = '1';
>> $number = '5';
>> $query = 'attr 1=4 test';
>> $id = yaz_connect('troy.lib.sfu.ca:210/innopac');
>> yaz_range($id, $start, $number);
>> yaz_syntax($id, 'marc21');
> 
> Use
>  yaz_syntax($id, "usmarc");
> instead.
>> yaz_search($id, 'rpn', $query);
>> yaz_present($id);
> It should not be necessary to use yaz_present.
(yaz_search will get the 
> range).
> 
> / Adam
> 
>> yaz_wait();
>>
>> // Formatting of results using XSL omitted
>>
>>
>> Number of records found: 1578
>> =============================
>> The biplane houses :poems /by Les Murray.
>> Embedded system design /by Peter Marwedel.
>> Hardening Windows systems /Roberta Bragg.
>> Java 2 :the complete reference /Patrick Naughton,
Herbert Schildt.
>> Practical MMIC design /Steve Marsh.
>>
>>
>> Since yaz_present() only takes the resource ID as a
parameter, and 
>> only returns TRUE or FALSE, I'm not sure how else
it would be used to 
>> produce results. The docs are sparse on this topic.
>>
>> Any pointers to complete examples, or to what I am
doing wrong, would 
>> be appreciated. I'd be happy to post my complete
script when it is 
>> working.
>>
>> Mark
>>
>> Mark Jordan
>> Head of Library Systems
>> W.A.C. Bennett Library, Simon Fraser University
>> Burnaby, British Columbia, V5A 1S6, Canada
>> Phone (604) 291 5753 / Fax (604) 291 3023
>> mjordansfu.ca / http://www.sfu.ca/~mjorda
n/
>>


_______________________________________________
Yazlist mailing list
Yazlistlists.indexdata.dk
http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list

Hi Mark,

FWIW, I've never been able to figure out how to make this
work on the 
server side. I do it on the client side, which in terms of
your script 
below would be done by substituting $start_at_rec for the
value 1 in 
your final loop.

for ($p = $start_at_rec; $p <= $max_recs; $p++) {
    $rec = yaz_record($id, $p, "xml; marc-8,
utf-8");
    if (empty($rec)) continue;
    print $rec;
  }

In other words, get the whole result set, and only display
the subset of 
records you're interested in.

I'm not sure whether this is good, bad, or indifferent in
terms of 
utilization of resources. It doesn't appear to impose any
great wait 
time on the execution of our search application, even with
large result 
sets, but maybe that's attributable to our reasonably decent
server 
hardware and low levels of use. I'd certainly be interested
to know if 
there's a better way to do it.

John


Mark Jordan wrote:
> Hi Adam,
> 
> I'm still missing something. Using yaz_syntax($id,
"usmarc") doesn't 
> make a difference. Here's my entire script (with record
formatting 
> removed -- it just prints records as XML):
> 
> <?php
> 
> $max_recs = 5;
> $query = $argv[1];
> $field = $argv[2];
> $start_at_rec = $argv[3];
> $query = trim($query);
> $field = trim($field);
> 
> $fields = array('title' => '4', 'author' =>
'1003', 'subject' => '21');
> 
> $query = 'attr 1=' . $fields[$field] . ' ' . $query;
> print "Query is $queryn";
> print "Starting at record $start_at_recn";
> 
> $id = yaz_connect('troy.lib.sfu.ca:210/innopac');
> yaz_range($id, $start_at_rec, $max_recs);
> yaz_syntax($id, "usmarc");
> yaz_search($id, 'rpn', $query);
> yaz_wait();
> 
> $error = yaz_error($id);
> if (!empty($error)) {
>   echo "Error: $error";
>   print "n";
>   exit;
> } else {
>   $hits = yaz_hits($id);
>   if ($hits == '0') {
>     print "No hitsn";
>     exit;
>   }
> }
> 
> for ($p = 1; $p <= $max_recs; $p++) {
>   $rec = yaz_record($id, $p, "xml; marc-8,
utf-8");
>   if (empty($rec)) continue;
>   print $rec;
> }
> 
> ?>
> 
> BTW I'm using PHP/YAZ version  1.0.7, YAZ version
2.1.36, PHP 5.1.6 on 
> FedoraCore 5/ppc.
> 
> Mark
> 
> Adam Dickmeiss wrote:
>> Mark Jordan wrote:
>>> Hello,
>>>
>>> I have been unable to figure out how to use the
yaz_present() 
>>> function to return subsets of my entire result
set. I couldn't find a 
>>> functional example anywhere (inc. the PHP docs
and the yaz mailing 
>>> list archives) so was hoping someone can tell
me what I'm doing wrong.
>>>
>>> In the following example, changing the value of
$start has no effect 
>>> on the records returned by by my search:
>>>
>>> $start = '1';
>>> $number = '5';
>>> $query = 'attr 1=4 test';
>>> $id =
yaz_connect('troy.lib.sfu.ca:210/innopac');
>>> yaz_range($id, $start, $number);
>>> yaz_syntax($id, 'marc21');
>>
>> Use
>>  yaz_syntax($id, "usmarc");
>> instead.
>>> yaz_search($id, 'rpn', $query);
>>> yaz_present($id);
>> It should not be necessary to use yaz_present.
(yaz_search will get 
>> the range).
>>
>> / Adam
>>
>>> yaz_wait();
>>>
>>> // Formatting of results using XSL omitted
>>>
>>>
>>> Number of records found: 1578
>>> =============================
>>> The biplane houses :poems /by Les Murray.
>>> Embedded system design /by Peter Marwedel.
>>> Hardening Windows systems /Roberta Bragg.
>>> Java 2 :the complete reference /Patrick
Naughton, Herbert Schildt.
>>> Practical MMIC design /Steve Marsh.
>>>
>>>
>>> Since yaz_present() only takes the resource ID
as a parameter, and 
>>> only returns TRUE or FALSE, I'm not sure how
else it would be used to 
>>> produce results. The docs are sparse on this
topic.
>>>
>>> Any pointers to complete examples, or to what I
am doing wrong, would 
>>> be appreciated. I'd be happy to post my
complete script when it is 
>>> working.
>>>
>>> Mark
>>>
>>> Mark Jordan
>>> Head of Library Systems
>>> W.A.C. Bennett Library, Simon Fraser University
>>> Burnaby, British Columbia, V5A 1S6, Canada
>>> Phone (604) 291 5753 / Fax (604) 291 3023
>>> mjordansfu.ca / http://www.sfu.ca/~mjorda
n/
>>>
> 
> 
> _______________________________________________
> Yazlist mailing list
> Yazlistlists.indexdata.dk
> http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list


-- 
John Durno
Coordinator, Information Technology Services
University of Victoria Libraries
PO Box 1800 STN CSC  Victoria, BC V8W 3H5

_______________________________________________
Yazlist mailing list
Yazlistlists.indexdata.dk
http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list

Mark Jordan wrote:
> Hi Adam,
> 
> I'm still missing something. Using yaz_syntax($id,
"usmarc") doesn't 
> make a difference. Here's my entire script (with record
formatting 
> removed -- it just prints records as XML):
I am confused about what you expected.. yaz_present should
send a 
present request using the range given. It does not return
anything. It's 
just a hint that you want a range to be returned. And these
results are 
inspected using yaz_record. You don't need yaz_present in a
program - in 
which case yaz_record will just fetch the record at that
point (one a time).

/ Adam

> <?php
> 
> $max_recs = 5;
> $query = $argv[1];
> $field = $argv[2];
> $start_at_rec = $argv[3];
> $query = trim($query);
> $field = trim($field);
> 
> $fields = array('title' => '4', 'author' =>
'1003', 'subject' => '21');
> 
> $query = 'attr 1=' . $fields[$field] . ' ' . $query;
> print "Query is $queryn";
> print "Starting at record $start_at_recn";
> 
> $id = yaz_connect('troy.lib.sfu.ca:210/innopac');
> yaz_range($id, $start_at_rec, $max_recs);
> yaz_syntax($id, "usmarc");
> yaz_search($id, 'rpn', $query);
> yaz_wait();
> 
> $error = yaz_error($id);
> if (!empty($error)) {
>   echo "Error: $error";
>   print "n";
>   exit;
> } else {
>   $hits = yaz_hits($id);
>   if ($hits == '0') {
>     print "No hitsn";
>     exit;
>   }
> }
> 
> for ($p = 1; $p <= $max_recs; $p++) {
>   $rec = yaz_record($id, $p, "xml; marc-8,
utf-8");
>   if (empty($rec)) continue;
>   print $rec;
> }
> 
> ?>
> 
> BTW I'm using PHP/YAZ version  1.0.7, YAZ version
2.1.36, PHP 5.1.6 on 
> FedoraCore 5/ppc.
> 
> Mark
> 
> Adam Dickmeiss wrote:
>> Mark Jordan wrote:
>>> Hello,
>>>
>>> I have been unable to figure out how to use the
yaz_present() 
>>> function to return subsets of my entire result
set. I couldn't find a 
>>> functional example anywhere (inc. the PHP docs
and the yaz mailing 
>>> list archives) so was hoping someone can tell
me what I'm doing wrong.
>>>
>>> In the following example, changing the value of
$start has no effect 
>>> on the records returned by by my search:
>>>
>>> $start = '1';
>>> $number = '5';
>>> $query = 'attr 1=4 test';
>>> $id =
yaz_connect('troy.lib.sfu.ca:210/innopac');
>>> yaz_range($id, $start, $number);
>>> yaz_syntax($id, 'marc21');
>>
>> Use
>>  yaz_syntax($id, "usmarc");
>> instead.
>>> yaz_search($id, 'rpn', $query);
>>> yaz_present($id);
>> It should not be necessary to use yaz_present.
(yaz_search will get 
>> the range).
>>
>> / Adam
>>
>>> yaz_wait();
>>>
>>> // Formatting of results using XSL omitted
>>>
>>>
>>> Number of records found: 1578
>>> =============================
>>> The biplane houses :poems /by Les Murray.
>>> Embedded system design /by Peter Marwedel.
>>> Hardening Windows systems /Roberta Bragg.
>>> Java 2 :the complete reference /Patrick
Naughton, Herbert Schildt.
>>> Practical MMIC design /Steve Marsh.
>>>
>>>
>>> Since yaz_present() only takes the resource ID
as a parameter, and 
>>> only returns TRUE or FALSE, I'm not sure how
else it would be used to 
>>> produce results. The docs are sparse on this
topic.
>>>
>>> Any pointers to complete examples, or to what I
am doing wrong, would 
>>> be appreciated. I'd be happy to post my
complete script when it is 
>>> working.
>>>
>>> Mark
>>>
>>> Mark Jordan
>>> Head of Library Systems
>>> W.A.C. Bennett Library, Simon Fraser University
>>> Burnaby, British Columbia, V5A 1S6, Canada
>>> Phone (604) 291 5753 / Fax (604) 291 3023
>>> mjordansfu.ca / http://www.sfu.ca/~mjorda
n/
>>>
> 
> 
> _______________________________________________
> Yazlist mailing list
> Yazlistlists.indexdata.dk
> http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list
> 
> .
> 


_______________________________________________
Yazlist mailing list
Yazlistlists.indexdata.dk
http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list

Adam Dickmeiss wrote:
> Mark Jordan wrote:
>> Hi Adam,
>>

> I am confused about what you expected.. yaz_present
should send a 
> present request using the range given. It does not
return anything. It's 
> just a hint that you want a range to be returned. And
these results are 
> inspected using yaz_record. You don't need yaz_present
in a program - in 
> which case yaz_record will just fetch the record at
that point (one a 
> time).
> 

I expected to be able to retrieve records 11-20 in a given
result set by 
using

$start = 11;
$number = 10;
yaz_range($id, $start, $number);

Since changing $start and $number don't seem to have any
effect on what 
records are retrieved (see the code snippet I included in my
first 
email), I thought that calling yaz_present() would. If
calling 
yaz_present() is unnecessary, I suggest the docs should say
so instead 
of implying that it should be called.

Perhaps John Durno's suggestion of getting the entire result
set and 
then picking out subsets for display is easier.

Mark


_______________________________________________
Yazlist mailing list
Yazlistlists.indexdata.dk
http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list

Hi Mark,

The problem, I think, is in your for() loop through the
records; I think 
it indicates a misunderstanding about how yaz_record()
works. Generally, 
the record offset that you give to yaz_record() is the
offset into the 
result set, not into any subset identified by yaz_range().
This is 
crucial: The yaz_range() function is strictly there to help
you write 
more optimized client code; you do not need to call it.

In other words, if you want to display record numbers 10 to
20 from your 
set, you loop from 10 to 20 and call yaz_record() for each
record. The 
underlying code will retrieve records as necessary on
demand.

However, if you call yaz_range() before you call yaz_wait(),
the 
underlying code will optimize it's behavior.. it will either
ask the 
server to return records along with the search recult, or
submit a 
single present request to fetch the records (if you're not
asking for 
too many).. it makes no difference in a quick hack, but it
can make a 
dramatic difference if you're designing for many users or
heavy traffic. 
Your loop over yaz_record() will be the same whether you
have called 
yaz_range() first, or not.

Looking at the documentation under php.net, I can understand
any 
confusion.. the 'ZOOM' abstraction attempts to make things
as simple as 
possible for the client programmers, allowing you to quickly
put 
together useful applications without worrying about protocol
mechanics. 
Functions like yaz_range() are there to help you write
better clients.

Hope this helps,

--Sebastian



Mark Jordan wrote:

> Hi Adam,
>
> I'm still missing something. Using yaz_syntax($id,
"usmarc") doesn't 
> make a difference. Here's my entire script (with record
formatting 
> removed -- it just prints records as XML):
>
> <?php
>
> $max_recs = 5;
> $query = $argv[1];
> $field = $argv[2];
> $start_at_rec = $argv[3];
> $query = trim($query);
> $field = trim($field);
>
> $fields = array('title' => '4', 'author' =>
'1003', 'subject' => '21');
>
> $query = 'attr 1=' . $fields[$field] . ' ' . $query;
> print "Query is $queryn";
> print "Starting at record $start_at_recn";
>
> $id = yaz_connect('troy.lib.sfu.ca:210/innopac');
> yaz_range($id, $start_at_rec, $max_recs);
> yaz_syntax($id, "usmarc");
> yaz_search($id, 'rpn', $query);
> yaz_wait();
>
> $error = yaz_error($id);
> if (!empty($error)) {
>   echo "Error: $error";
>   print "n";
>   exit;
> } else {
>   $hits = yaz_hits($id);
>   if ($hits == '0') {
>     print "No hitsn";
>     exit;
>   }
> }
>
> for ($p = 1; $p <= $max_recs; $p++) {
>   $rec = yaz_record($id, $p, "xml; marc-8,
utf-8");
>   if (empty($rec)) continue;
>   print $rec;
> }
>
> ?>
>
> BTW I'm using PHP/YAZ version  1.0.7, YAZ version
2.1.36, PHP 5.1.6 on 
> FedoraCore 5/ppc.
>
> Mark
>
> Adam Dickmeiss wrote:
>
>> Mark Jordan wrote:
>>
>>> Hello,
>>>
>>> I have been unable to figure out how to use the
yaz_present() 
>>> function to return subsets of my entire result
set. I couldn't find 
>>> a functional example anywhere (inc. the PHP
docs and the yaz mailing 
>>> list archives) so was hoping someone can tell
me what I'm doing wrong.
>>>
>>> In the following example, changing the value of
$start has no effect 
>>> on the records returned by by my search:
>>>
>>> $start = '1';
>>> $number = '5';
>>> $query = 'attr 1=4 test';
>>> $id =
yaz_connect('troy.lib.sfu.ca:210/innopac');
>>> yaz_range($id, $start, $number);
>>> yaz_syntax($id, 'marc21');
>>
>>
>> Use
>>  yaz_syntax($id, "usmarc");
>> instead.
>>
>>> yaz_search($id, 'rpn', $query);
>>> yaz_present($id);
>>
>> It should not be necessary to use yaz_present.
(yaz_search will get 
>> the range).
>>
>> / Adam
>>
>>> yaz_wait();
>>>
>>> // Formatting of results using XSL omitted
>>>
>>>
>>> Number of records found: 1578
>>> =============================
>>> The biplane houses :poems /by Les Murray.
>>> Embedded system design /by Peter Marwedel.
>>> Hardening Windows systems /Roberta Bragg.
>>> Java 2 :the complete reference /Patrick
Naughton, Herbert Schildt.
>>> Practical MMIC design /Steve Marsh.
>>>
>>>
>>> Since yaz_present() only takes the resource ID
as a parameter, and 
>>> only returns TRUE or FALSE, I'm not sure how
else it would be used 
>>> to produce results. The docs are sparse on this
topic.
>>>
>>> Any pointers to complete examples, or to what I
am doing wrong, 
>>> would be appreciated. I'd be happy to post my
complete script when 
>>> it is working.
>>>
>>> Mark
>>>
>>> Mark Jordan
>>> Head of Library Systems
>>> W.A.C. Bennett Library, Simon Fraser University
>>> Burnaby, British Columbia, V5A 1S6, Canada
>>> Phone (604) 291 5753 / Fax (604) 291 3023
>>> mjordansfu.ca / http://www.sfu.ca/~mjorda
n/
>>>
>
>
> _______________________________________________
> Yazlist mailing list
> Yazlistlists.indexdata.dk
> http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list
>
>

-- 
Sebastian Hammer, Index Data
quinnindexdata.com   www.indexdata.com
Ph: (603) 209-6853 Fax: (866) 383-4485


_______________________________________________
Yazlist mailing list
Yazlistlists.indexdata.dk
http://lists.indexdata.dk/cgi-bin/mailman/listinfo/yaz
list