php-doc-en/reference/yaz/reference.xml

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<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.9 $ -->
<reference id="ref.yaz">
<title>YAZ functions</title>
<titleabbrev>YAZ</titleabbrev>
<partintro>
<section id="yaz.intro">
&reftitle.intro;
<para>
This extension offers a PHP interface to the
<productname>YAZ</productname> toolkit that implements the
<ulink url="&url.yaz-loc;">Z39.50
Protocol for Information Retrieval</ulink>.
With this extension you can easily implement a Z39.50 origin (client)
that searches or scans Z39.50 targets (servers) in parallel.
</para>
<para>
The module hides most of the complexity of Z39.50 so it should be
fairly easy to use. It supports persistent stateless connections very
similar to those offered by the various RDB APIs that are available
for PHP. This means that sessions are stateless but shared amongst
users, thus saving the connect and initialize phase steps in most
cases.
</para>
<para>
<productname>YAZ</productname> is available at <ulink
url="&url.yaz;">&url.yaz;</ulink>. You can find news information,
example scripts, etc. for this extension at <ulink
url="&url.yaz-phpyaz;">&url.yaz-phpyaz;</ulink>.
</para>
</section>
&reference.yaz.configure;
&reference.yaz.ini;
<section id="yaz.resources">
&reftitle.resources;
&no.resource;
</section>
<section id="yaz.constants">
&reftitle.constants;
&no.constants;
</section>
<section id="yaz.examples">
&reftitle.examples;
<para>
PHP/YAZ keeps track of connections with targets
(Z-Associations). A resource represents a connection to a
target.
</para>
<para>
The script below demonstrates the parallel searching feature of
the API. When invoked with no arguments it prints a query form; else
(arguments are supplied) it searches the targets as given in array
<literal>host</literal>.
</para>
<para>
<example>
<title>Parallel searching using Yaz</title>
<programlisting role="php">
<![CDATA[
$num_hosts = count ($host);
if (empty($term) || count($host) == 0) {
echo '<form method="get">
<input type="checkbox"
name="host[]" value="bagel.indexdata.dk/gils">
GILS test
<input type="checkbox"
name="host[]" value="localhost:9999/Default">
local test
<input type="checkbox" checked="1"
name="host[]" value="z3950.loc.gov:7090/voyager">
Library of Congress
<br>
RPN Query:
<input type="text" size="30" name="term">
<input type="submit" name="action" value="Search">
';
} else {
echo 'You searced for ' . htmlspecialchars($term) . '<br>';
for ($i = 0; $i < $num_hosts; $i++) {
$id[] = yaz_connect($host[$i]);
yaz_range($id[$i], 1, 10);
yaz_search($id[$i],"rpn",$term);
}
yaz_wait();
for ($i = 0; $i < $num_hosts; $i++) {
echo '<hr>' . $host[$i] . ":";
$error = yaz_error($id[$i]);
if (!empty($error)) {
echo "Error: $error";
} else {
$hits = yaz_hits($id[$i]);
echo "Result Count $hits";
}
echo '<dl>';
for ($p = 1; $p <= 10; $p++) {
$rec = yaz_record($id[$i],$p,"string");
if (empty($rec)) continue;
echo "<dt><b>$p</b></dt><dd>";
echo ereg_replace("\n", "<br>\n",$rec);
echo "</dd>";
}
echo '</dl>';
}
}
]]>
</programlisting>
</example>
</para>
</section>
</partintro>
&reference.yaz.functions;
</reference>
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