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<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>6.�Scan</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="YAZ User's Guide and Reference"><link rel="up" href="zoom.html" title="Chapter�3.�ZOOM"><link rel="prev" href="zoom.facets.html" title="5.�Facets"><link rel="next" href="zoom.extendedservices.html" title="7.�Extended Services"></head><body><link rel="stylesheet" type="text/css" href="common/style1.css"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">6.�Scan</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="zoom.facets.html">Prev</a>�</td><th width="60%" align="center">Chapter�3.�ZOOM</th><td width="20%" align="right">�<a accesskey="n" href="zoom.extendedservices.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="zoom.scan"></a>6.�Scan</h2></div></div></div><p>
This section describes an interface for Scan. Scan is not an
official part of the ZOOM model yet. The result of a scan operation
is the <code class="literal">ZOOM_scanset</code> which is a set of terms
returned by a target.
</p><p>
The Scan interface is supported for both Z39.50, SRU and Solr.
</p><pre class="synopsis">
ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
const char *startpqf);
ZOOM_scanset ZOOM_connection_scan1(ZOOM_connection c,
ZOOM_query q);
size_t ZOOM_scanset_size(ZOOM_scanset scan);
const char *ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
size_t *occ, size_t *len);
const char *ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
size_t *occ, size_t *len);
void ZOOM_scanset_destroy(ZOOM_scanset scan);
const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
const char *key);
void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
const char *val);
</pre><p>
The scan set is created by function
<code class="function">ZOOM_connection_scan</code> which performs a scan
operation on the connection using the specified
<em class="parameter"><code>startpqf</code></em>.
If the operation was successful, the size of the scan set can be
retrieved by a call to <code class="function">ZOOM_scanset_size</code>.
Like result sets, the items are numbered 0,..size-1.
To obtain information about a particular scan term, call function
<code class="function">ZOOM_scanset_term</code>. This function takes
a scan set offset <code class="literal">pos</code> and returns a pointer
to a <span class="emphasis"><em>raw term</em></span> or <code class="literal">NULL</code> if
non-present.
If present, the <code class="literal">occ</code> and <code class="literal">len</code>
are set to the number of occurrences and the length
of the actual term respectively.
<code class="function">ZOOM_scanset_display_term</code> is similar to
<code class="function">ZOOM_scanset_term</code> except that it returns
the <span class="emphasis"><em>display term</em></span> rather than the raw term.
In a few cases, the term is different from display term. Always
use the display term for display and the raw term for subsequent
scan operations (to get more terms, next scan result, etc).
</p><p>
A scan set may be freed by a call to function
<code class="function">ZOOM_scanset_destroy</code>.
Functions <code class="function">ZOOM_scanset_option_get</code> and
<code class="function">ZOOM_scanset_option_set</code> retrieves and sets
an option respectively.
</p><p>
The <em class="parameter"><code>startpqf</code></em> is a subset of PQF, namely
the Attributes+Term part. Multiple <code class="literal">@attr</code> can
be used. For example to scan in title (complete) phrases:
</p><div class="literallayout"><p><br>
�����@attr�1=4�@attr�6=2�"science�o"<br>
����</p></div><p>
</p><p>
The <code class="function">ZOOM_connecton_scan1</code> is a newer and
more generic alternative to <code class="function">ZOOM_connection_scan</code>
which allows to use both CQL and PQF for Scan.
</p><div class="table"><a name="zoom.scanset.options"></a><p class="title"><b>Table�3.5.�ZOOM Scan Set Options</b></p><div class="table-contents"><table summary="ZOOM Scan Set Options" border="1"><colgroup><col class="name"><col class="description"><col class="default"></colgroup><thead><tr><th>Option</th><th>Description</th><th>Default</th></tr></thead><tbody><tr><td>
number</td><td>Number of Scan Terms requested in next scan.
After scan it holds the actual number of terms returned.
</td><td>20</td></tr><tr><td>
position</td><td>Preferred Position of term in response
in next scan; actual position after completion of scan.
</td><td>1</td></tr><tr><td>
stepSize</td><td>Step Size
</td><td>0</td></tr><tr><td>
scanStatus</td><td>An integer indicating the Scan Status
of last scan.
</td><td>0</td></tr><tr><td>
rpnCharset</td><td>Character set for RPN terms.
If this is set, ZOOM C will assume that the ZOOM application is
running UTF-8. Terms in RPN queries are then converted to the
rpnCharset. If this is unset, ZOOM C will not assume any encoding
of RPN terms and no conversion is performed.
</td><td>none</td></tr></tbody></table></div></div><br class="table-break"></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="zoom.facets.html">Prev</a>�</td><td width="20%" align="center"><a accesskey="u" href="zoom.html">Up</a></td><td width="40%" align="right">�<a accesskey="n" href="zoom.extendedservices.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">5.�Facets�</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">�7.�Extended Services</td></tr></table></div></body></html>