Mention SRU rather than SRW (where appropriate).
[yaz-moved-to-github.git] / doc / zoom.xml
index 1a4efe0..29f9514 100644 (file)
@@ -1,6 +1,27 @@
-<!-- $Id: zoom.xml,v 1.16 2002-01-03 12:18:37 adam Exp $ -->
- <chapter id="zoom"><title>Building clients with ZOOM</title>
-  
+<!--
+### Still to document:
+ZOOM_connection_errcode(c)
+ZOOM_connection_errmsg(c)
+ZOOM_connection_addinfo(c)
+ZOOM_connection_addinfo(c)
+ZOOM_connection_diagset(c);
+ZOOM_diag_str(error)
+ZOOM_resultset_record_immediate(s, pos)
+ZOOM_resultset_cache_reset(r)
+ZOOM_resultset_sort(r, sort_type, sort_spec)
+ZOOM_resultset_sort1(r, sort_type, sort_spec)
+ZOOM_options_set_callback(opt, function, handle)
+ZOOM_options_create_with_parent2(parent1, parent2)
+ZOOM_options_getl(opt, name, len)
+ZOOM_options_setl(opt, name, value, len)
+ZOOM_options_get_bool(opt, name, defa)
+ZOOM_options_get_int(opt, name, defa)
+ZOOM_options_set_int(opt, name, value)
+ZOOM_connection_scan1 (ZOOM_connection c, ZOOM_query startterm)
+ZOOM_query_cql2rpn(ZOOM_query s, const char *str, ZOOM_connection conn)
+-->
+<!-- $Id: zoom.xml,v 1.50 2006-06-13 16:01:51 adam Exp $ -->
+ <chapter id="zoom"><title>ZOOM</title>
   <para>
     &zoom; is an acronym for 'Z39.50 Object-Orientation Model' and is
    an initiative started by Mike Taylor (Mike is from the UK, which
    provide a common Z39.50 client API not bound to a particular
    programming language or toolkit.
   </para>
+
+  <note>
+   <para>
+    A recent addition to &yaz; is SRU support. You can now make
+    SRU ZOOM connections by specifying scheme <literal>http://</literal>
+    for the hostname for a connection.
+   </para>
+  </note>
+
   <para>
    The lack of a simple Z39.50 client API for &yaz; has become more
    and more apparent over time. So when the first &zoom; specification
    became available,
    an implementation for &yaz; was quickly developed. For the first time, it is
    now as easy (or easier!) to develop clients than servers with &yaz;. This
-   chapter describes the &zoom; C binding. Before going futher, please
+   chapter describes the &zoom; C binding. Before going further, please
    reconsider whether C is the right programming language for the job.
    There are other language bindings available for &yaz;, and still
    more
    are in active development. See the
-   <ulink url="http://zoom.z3950.org/">ZOOM website</ulink> for
+   <ulink url="&url.zoom;">ZOOM web-site</ulink> for
    more information.
   </para>
-
+  
   <para>
    In order to fully understand this chapter you should read and
    try the example programs <literal>zoomtst1.c</literal>,
    <literal>zoomtst2.c</literal>, .. in the <literal>zoom</literal>
    directory.
   </para>
-
+  
   <para>
    The C language misses features found in object oriented languages
    such as C++, Java, etc. For example, you'll have to manually,
@@ -42,7 +72,7 @@
   </para>
   <para>
    In each of the sections below you'll find a sub section called
-   protocol behavior, that descries how the API maps to the Z39.50
+   protocol behavior, that describes how the API maps to the Z39.50
    protocol.
   </para>
   <sect1 id="zoom.connections"><title>Connections</title>
    <para>The Connection object is a session with a target.
    </para>
    <synopsis>
-   #include &lt;yaz/zoom.h>
+    #include &lt;yaz/zoom.h>
     
-   ZOOM_connection ZOOM_connection_new (const char *host, int portnum);
+    ZOOM_connection ZOOM_connection_new (const char *host, int portnum);
     
-   ZOOM_connection ZOOM_connection_create (ZOOM_options options);
-
-   void ZOOM_connection_connect(ZOOM_connection c, const char *host,
+    ZOOM_connection ZOOM_connection_create (ZOOM_options options);
+    
+    void ZOOM_connection_connect(ZOOM_connection c, const char *host,
                                  int portnum);
-   void ZOOM_connection_destroy (ZOOM_connection c);
+    void ZOOM_connection_destroy (ZOOM_connection c);
    </synopsis>
    <para>
     Connection objects are created with either function
     a connection immediately, thus allowing you to specify options
     before establishing network connection using the function
     <function>ZOOM_connection_connect</function>. 
-    If the portnumber, <literal>portnum</literal>, is zero, the
+    If the port number, <literal>portnum</literal>, is zero, the
     <literal>host</literal> is consulted for a port specification.
     If no port is given, 210 is used. A colon denotes the beginning of
     a port number in the host string. If the host string includes a
     slash, the following part specifies a database for the connection.
    </para>
    <para>
+    You can prefix the host with a scheme followed by colon. The
+    default scheme is <literal>tcp</literal> (Z39.50 protocol).
+    The scheme <literal>http</literal> selects SRU over HTTP.
+   </para>
+   <para>
+    You can prefix the scheme-qualified host-string with one or more
+    comma-separated
+    <literal><parameter>key</parameter>=<parameter>value</parameter></literal>
+    sequences, each of which represents an option to be set into the
+    connection structure <emphasis>before</emphasis> the
+    protocol-level connection is forged and the initialisation
+    handshake takes place.  This facility can be used to provide
+    authentication credentials, as in host-strings such as:
+    <literal>user=admin,password=halfAm4n,tcp:localhost:8017/db</literal>
+   </para>
+   <para>
     Connection objects should be destroyed using the function
     <function>ZOOM_connection_destroy</function>.
    </para>
    <synopsis>
-    void ZOOM_connection_option_set (ZOOM_connection c,
+    void ZOOM_connection_option_set(ZOOM_connection c,
+                                    const char *key, const char *val);
+
+    void ZOOM_connection_option_setl(ZOOM_connection c,
                                      const char *key,
-                                     const char *val);
+                                     const char *val, int len);
 
-    const char *ZOOM_connection_option_get (ZOOM_connection c,
-                                            const char *key);
+    const char *ZOOM_connection_option_get(ZOOM_connection c,
+                                           const char *key);
+    const char *ZOOM_connection_option_getl(ZOOM_connection c,
+                                            const char *key,
+                                            int *lenp);
    </synopsis>
    <para>
-    The <function>ZOOM_connection_option_set</function> allows you to
+    The functions <function>ZOOM_connection_option_set</function> and
+    <function>ZOOM_connection_option_setl</function> allows you to
     set an option given by <parameter>key</parameter> to the value
-    <parameter>value</parameter> for the connection.
-     Function <function>ZOOM_connection_option_get</function> returns
+    <parameter>value</parameter> for the connection. 
+    For <function>ZOOM_connection_option_set</function>, the
+    value is assumed to be a 0-terminated string. Function
+    <function>ZOOM_connection_option_setl</function> specifies a
+    value of a certain size (len).
+   </para>
+   <para>
+    Functions <function>ZOOM_connection_option_get</function> and
+    <function>ZOOM_connection_option_getl</function> returns
     the value for an option given by <parameter>key</parameter>.
    </para>
-   <table frame="sides" colsep="1"><title>ZOOM Connection Options</title>
+   <table frame="top"><title>ZOOM Connection Options</title>
     <tgroup cols="3">
      <colspec colwidth="4*" colname="name"></colspec>
      <colspec colwidth="7*" colname="description"></colspec>
         group</entry><entry>Authentication group name
        </entry><entry>none</entry></row>
       <row><entry>
-        pass</entry><entry>Authentication password
-      </entry><entry>none</entry></row>
+        password</entry><entry>Authentication password.
+       </entry><entry>none</entry></row>
       <row><entry>
         host</entry><entry>Target host. This setting is "read-only".
         It's automatically set internally when connecting to a target.
       <row><entry>
         preferredMessageSize</entry><entry> Maximum size of multiple records.
        </entry><entry>1 MB</entry></row>
+      <row><entry>
+        lang</entry><entry> Language for negotiation.
+       </entry><entry>none</entry></row>
+      <row><entry>
+        charset</entry><entry> Character set for negotiation.
+       </entry><entry>none</entry></row>
+      <row><entry>
+        serverImplementationId</entry><entry>
+       Implementation ID of server.  (The old targetImplementationId
+       option is also supported for the benefit of old applications.)
+       </entry><entry>none</entry></row>
+      <row><entry>
+        targetImplementationName</entry><entry>
+       Implementation Name of server.  (The old
+       targetImplementationName option is also supported for the
+       benefit of old applications.)
+       </entry><entry>none</entry></row>
+      <row><entry>
+        serverImplementationVersion</entry><entry>
+       Implementation Version of server.  (the old
+       targetImplementationVersion option is also supported for the
+       benefit of old applications.)
+       </entry><entry>none</entry></row>
+      <row><entry>
+        databaseName</entry><entry>One or more database names
+        separated by character plus (<literal>+</literal>), which to
+        be used by subsequent search requests on this Connection.
+       </entry><entry>Default</entry></row>
+      <row><entry>
+        piggyback</entry><entry>True (1) if piggyback should be
+        used in searches; false (0) if not.
+       </entry><entry>1</entry></row>
+      <row><entry>
+        smallSetUpperBound</entry><entry>If hits is less than or equal to this
+        value, then target will return all records using small element set name
+       </entry><entry>0</entry></row>
+      <row><entry>
+        largeSetLowerBound</entry><entry>If hits is greater than this
+        value, the target will return no records.
+       </entry><entry>1</entry></row>
+      <row><entry>
+        mediumSetPresentNumber</entry><entry>This value represents
+        the number of records to be returned as part of a search when when
+        hits is less than or equal to large set lower bound and if hits
+        is greater than small set upper bound.
+       </entry><entry>0</entry></row>
+      <row><entry>
+        smallSetElementSetName</entry><entry>
+        The element set name to be used for small result sets.
+       </entry><entry>none</entry></row>
+      <row><entry>
+        mediumSetElementSetName</entry><entry>
+        The element set name to be for medium-sized result sets.
+       </entry><entry>none</entry></row>
      </tbody>
     </tgroup>
    </table>
+   <para>
+    If either option <literal>lang</literal> or <literal>charset</literal>
+    is set, then 
+    <ulink url="&url.z39.50.charneg;">
+     Character Set and Language Negotiation</ulink> is in effect.
+   </para>
    <synopsis>
      int ZOOM_connection_error (ZOOM_connection c, const char **cp,
-                                 const char **addinfo);
+                                const char **addinfo);
+     int ZOOM_connection_error_x (ZOOM_connection c, const char **cp,
+                                  const char **addinfo, const char **dset);
    </synopsis>
    <para>
-    Use <function>ZOOM_connection_error</function> to check for
+    Function <function>ZOOM_connection_error</function> checks for
     errors for the last operation(s) performed. The function returns
     zero if no errors occurred; non-zero otherwise indicating the error.
     Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
     holds messages for the error and additional-info if passed as
-    non-<literal>NULL</literal>.
+    non-<literal>NULL</literal>. Function
+    <function>ZOOM_connection_error_x</function> is an extended version
+    of <function>ZOOM_connection_error</function> that is capable of
+    returning name of diagnostic set in <parameter>dset</parameter>.
    </para>
-   <sect2><title>Protocol behavior</title>
+   <sect2><title>Z39.50 Protocol behavior</title>
     <para>
      The calls <function>ZOOM_connection_new</function> and
-     <function>ZOOM_connection_connect</function> establises a TCP/IP
+     <function>ZOOM_connection_connect</function> establishes a TCP/IP
       connection and sends an Initialize Request to the target if
       possible. In addition, the calls waits for an Initialize Response
       from the target and the result is inspected (OK or rejected).
      API cannot tell the outcome (yet).
     </para>
     </sect2>
+   <sect2><title>SRU Protocol behavior</title>
+    <para>
+     The SRU protocol doesn't feature an Inititialize Request, so
+     the connection phase merely establishes a TCP/IP connection
+     with the SOAP service.
+    </para>
+    <para>Most of the ZOOM connection options do not
+     affect SRU and they are ignored. However, future versions
+     of &yaz; might honor <literal>implementationName</literal> and
+     put that as part of User-Agent header for HTTP requests.
+     </para>
+    <para>
+     The <literal>charset</literal> is used in the Content-Type header
+     of HTTP requests.
+    </para>
+   </sect2>
   </sect1>
   <sect1 id="zoom.query"><title>Queries</title>
    <para>
 
      int ZOOM_query_prefix(ZOOM_query q, const char *str);
 
+     int ZOOM_query_cql(ZOOM_query s, const char *str);
+
      int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
    </synopsis>
    <para>
     and destroy them by calling <function>ZOOM_query_destroy</function>.
     RPN-queries can be specified in <link linkend="PQF">PQF</link>
     notation by using the
-    function <function>ZOOM_query_prefix</function>. More
-    query types will be added later, such as
+    function <function>ZOOM_query_prefix</function>.
+    The <function>ZOOM_query_cql</function> specifies a CQL
+    query to be sent to the server/target.
+    More query types will be added in future versions of &yaz;, such as
     <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
     etc. In addition to a search, a sort criteria may be set. Function
     <function>ZOOM_query_sortby</function> specifies a 
      </thead>
      <tbody>
       <row><entry>
-        piggyback</entry><entry>True (1) if piggyback should be
-        used in searches; false (0) if not.
-       </entry><entry>1</entry></row>
-      <row><entry>
         start</entry><entry>Offset of first record to be 
         retrieved from target. First record has offset 0 unlike the
         protocol specifications where first record has position 1.
         count</entry><entry>Number of records to be retrieved.
        </entry><entry>0</entry></row>
       <row><entry>
+       presentChunk</entry><entry>The number of records to be
+       requested from the server in each chunk (present requst).  The
+       value 0 means to request all the records in a single chunk.
+       (The old <literal>step</literal>
+       option is also supported for the benefit of old applications.)
+       </entry><entry>0</entry></row>
+      <row><entry>
         elementSetName</entry><entry>Element-Set name of records. 
         Most targets should honor element set name <literal>B</literal>
         and <literal>F</literal> for brief and full respectively.
         <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
        </entry><entry>none</entry></row>
       <row><entry>
-        smallSetUpperBound</entry><entry>If hits is less than or equal to this
-        value, then target will return all records using small element set name
-       </entry><entry>0</entry></row>
-      <row><entry>
-        largeSetLowerBound</entry><entry>If hits is greator than this
-        value, the target will return no records.
-       </entry><entry>1</entry></row>
-      <row><entry>
-        mediumSetPresentNumber</entry><entry>This value represents
-        the number of records to be returned as part of a search when when
-        hits is less than or equal to large set lower bound and if hits
-        is greator than small set upper bound.
-       </entry><entry>0</entry></row>
-      <row><entry>
-        smallSetElementSetName</entry><entry>
-        The element set name to be used for small result sets.
-       </entry><entry>none</entry></row>
-      <row><entry>
-        mediumSetElementSetName</entry><entry>
-        The element set name to be for medium-sized result sets.
-       </entry><entry>none</entry></row>
-      <row><entry>
-        databaseName</entry><entry>One or more database names
-        separated by character plus (<literal>+</literal>).
-       </entry><entry>Default</entry></row>
-      <row><entry>
         setname</entry><entry>Name of Result Set (Result Set ID).
         If this option isn't set, the ZOOM module will automatically
         allocate a result set name.
      </tbody>
     </tgroup>
    </table>
+   <para>
+    For servers that support Search Info report, the following
+    options may be read using <function>ZOOM_resultset_get</function>.
+    This detailed information is read after a successful search has
+    completed.
+   </para>
+   <para>
+    This information is a list of of items, where each item is
+    information about a term or subquery. All items in the list 
+    are prefixed by 
+    <literal>SearchResult.</literal><replaceable>no</replaceable>
+    where no presents the item number (0=first, 1=second). 
+    Read <literal>searchresult.size</literal> to determine the
+    number of items.
+   </para>
+   <table frame="top"><title>Search Info Report options</title>
+    <tgroup cols="2">
+     <colspec colwidth="4*" colname="name"></colspec>
+     <colspec colwidth="7*" colname="description"></colspec>
+     <thead>
+      <row>
+       <entry>Option</entry>
+       <entry>Description</entry>
+      </row>
+     </thead>
+     <tbody>
+      <row>
+       <entry>searchresult.size</entry>
+       <entry>
+       number of search result entries. This option is-nonexistant
+       if no entries are returned by the server.
+       </entry>
+      </row>
+      <row>
+       <entry>searchresult.<replaceable>no</replaceable>.id</entry>
+       <entry>sub query ID</entry>
+      </row>
+      <row>
+       <entry>searchresult.<replaceable>no</replaceable>.count</entry>
+       <entry>result count for item (number of hits)</entry>
+      </row>
+      <row>
+       <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
+       <entry>subquery term</entry>
+      </row>
+      <row>
+       <entry>
+       searchresult.<replaceable>no</replaceable>.interpretation.term
+       </entry>
+       <entry>interpretation term</entry>
+      </row>
+      <row>
+       <entry>
+       searchresult.<replaceable>no</replaceable>.recommendation.term
+       </entry>
+       <entry>recommendation term</entry>
+      </row>
+     </tbody>
+    </tgroup>
+   </table>
    <sect2>
-    <title>Protocol behavior</title>
+    <title>Z39.50 Protocol behavior</title>
     <para>
      The creation of a result set involves at least a SearchRequest
      - SearchResponse protocol handshake. Following that, if a sort
-     critieria was specified as part of the query, a sortRequest -
+     criteria was specified as part of the query, a SortRequest -
      SortResponse handshake takes place. Note that it is necessary to
      perform sorting before any retrieval takes place, so no records will
      be returned from the target as part of the SearchResponse because these
-     would be unsorted. Hence, piggyback is disabled when sort critieria
-     is set. Following Search - and a Possible sort, Retrieval takes
-     place - as one or more Present Requests - Present Response being
+     would be unsorted. Hence, piggyback is disabled when sort criteria
+     are set. Following Search - and a possible sort - Retrieval takes
+     place - as one or more Present Requests/Response pairs being
      transferred.
      </para>
     <para>
      The API allows for two different modes for retrieval. A high level
      mode which is somewhat more powerful and a low level one.
-     The low level is "enabled" when the settings
+     The low level is enabled when searching on a Connection object
+     for which the settings
      <literal>smallSetUpperBound</literal>,
      <literal>mediumSetPresentNumber</literal> and
      <literal>largeSetLowerBound</literal> are set. The low level mode
      because of a record size limit, etc. the client will repeat sending
      present requests. As an example, if option <literal>start</literal>
      is 0 (default) and <literal>count</literal> is 4, and
-     <literal>piggyback</literal> is 1 (default) and no sorting critieria
+     <literal>piggyback</literal> is 1 (default) and no sorting criteria
      is specified, then the client will attempt to retrieve the 4
      records as part the search response (using piggyback). On the other
      hand, if either <literal>start</literal> is positive or if
      to specify one elementSetName option rather than three.
      </para>
    </sect2>
+   <sect2>
+    <title>SRU Protocol behavior</title>
+    <para>
+     Current version of &yaz; does not take advantage of a result set id
+     returned by the SRU server. Future versions might do, however.
+     Since, the ZOOM driver does not save result set IDs any
+     present (retrieval) is transformed to a SRU SearchRetrieveRequest
+     with same query but, possibly, different offsets.
+    </para>
+    <para>
+     Option <literal>schema</literal> specifies SRU schema
+     for retrieval. However, options <literal>elementSetName</literal> and
+     <literal>preferredRecordSyntax</literal> are ignored.
+    </para>
+    <para>
+     Options <literal>start</literal> and <literal>count</literal> 
+     are supported by SRU.
+     The remaining options
+     <literal>piggyback</literal>, 
+     <literal>smallSetUpperBound</literal>, 
+     <literal>largeSetLowerBound</literal>, 
+     <literal>mediumSetPresentNumber</literal>, 
+     <literal>mediumSetElementSetName</literal>,
+      <literal>smallSetElementSetName</literal> are
+     unsupported.
+    </para>
+    <para>
+     SRU supports CQL queries, <emphasis>not</emphasis> PQF.
+     If PQF is used, however, the PQF query is transferred anyway
+     using non-standard element <literal>pQuery</literal> in
+     SRU SearchRetrieveRequest.
+    </para>
+    <para>
+     Unfortunately, SRU does not define a database setting. Hence,
+     <literal>databaseName</literal> is unsupported and ignored.
+     However, the path part in host parameter for functions 
+     <function>ZOOM_connecton_new</function> and
+     <function>ZOOM_connection_connect</function> acts as a
+     database (at least for the &yaz; SRU server).
+    </para>
+   </sect2>
   </sect1>
   <sect1 id="zoom.records"><title>Records</title>
    <para>
-    A record object is a retrival record on the client side -
+    A record object is a retrieval record on the client side -
     created from result sets.
    </para>
    <synopsis>
                                   size_t start, size_t count);
      ZOOM_record ZOOM_resultset_record (ZOOM_resultset s, size_t pos);
 
-     void *ZOOM_record_get (ZOOM_record rec, const char *type,
-                            size_t *len);
+     const char *ZOOM_record_get (ZOOM_record rec, const char *type,
+                                  size_t *len);
 
      ZOOM_record ZOOM_record_clone (ZOOM_record rec);
 
     <function>ZOOM_record_get</function> is provided. The
     function returns a pointer to certain record information. The
     nature (type) of the pointer depends on the parameter,
-    <function>type</function>.
+    <parameter>type</parameter>.
+   </para>
+   <para>
+    The <parameter>type</parameter> is a string of the format:
+   </para>
+   <para>
+    <replaceable>form</replaceable>[; charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]]
+   </para>
+   <para>
+    where <replaceable>form</replaceable> specifies the format of the
+    returned record, <replaceable>from</replaceable>
+    specifies the character set of the record in its original form
+    (as returned by the server), <replaceable>to</replaceable> specifies
+    the output (returned)
+    character set encoding.
+    If charset is not given, then no character set conversion takes place.
+    If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
+   </para>
+   <para>
     In addition, for certain types, the length
     <literal>len</literal> passed will be set to the size in bytes of
-    the returned information.
+    the returned information. 
+    </para>
+   <para>
+    The following are the supported values for <replaceable>form</replaceable>.
     <variablelist>
      <varlistentry><term><literal>database</literal></term>
       <listitem><para>Database of record is returned
-        as a C null-terminated string. Return type <literal>char *</literal>. 
+        as a C null-terminated string. Return type
+        <literal>const char *</literal>. 
        </para></listitem>
-      </varlistentry>
+     </varlistentry>
      <varlistentry><term><literal>syntax</literal></term>
-      <listitem><para>The transfer syntax (OID) of the record is returned
-        as a C null-terminated string. Return type <literal>char *</literal>. 
+      <listitem><para>The transfer syntax of the record is returned
+        as a C null-terminated string containing the symbolic name of
+       the record syntax, e.g. <literal>Usmarc</literal>. Return type
+       is
+        <literal>const char *</literal>. 
        </para></listitem>
-      </varlistentry>
+     </varlistentry>
      <varlistentry><term><literal>render</literal></term>
       <listitem><para>The record is returned in a display friendly
         format. Upon completion buffer is returned
-        (type <literal>char *</literal>) and length is stored in
+        (type <literal>const char *</literal>) and length is stored in
         <literal>*len</literal>.
        </para></listitem>
-      </varlistentry>
+     </varlistentry>
      <varlistentry><term><literal>raw</literal></term>
       <listitem><para>The record is returned in the internal
-        YAZ specific format. The raw data is returned as type 
+        YAZ specific format. For GRS-1, Explain, and others, the
+        raw data is returned as type 
         <literal>Z_External *</literal> which is just the type for
         the member <literal>retrievalRecord</literal> in
         type <literal>NamePlusRecord</literal>.
+        For SUTRS and octet aligned record (including all MARCs) the
+        octet buffer is returned and the length of the buffer.
+       </para></listitem>
+     </varlistentry>
+     <varlistentry><term><literal>xml</literal></term>
+      <listitem><para>The record is returned in XML if possible.
+       SRU and Z39.50 records with transfer syntax XML are
+       returned verbatim. MARC records are returned in
+       <ulink url="&url.marcxml;">
+        MARCXML
+        </ulink> 
+       (converted from ISO2709 to MARCXML by YAZ).
+       GRS-1 and OPAC records are not supported for this form.
+        Upon completion, the XML buffer is returned
+       (type <literal>const char *</literal>) and length is stored in
+        <literal>*len</literal>.
+       </para></listitem>
+     </varlistentry>
+     <varlistentry><term><literal>opac</literal></term>
+      <listitem><para>OPAC for record is returned in XML.
        </para></listitem>
-      </varlistentry>
+     </varlistentry>
     </variablelist>
    </para>
-   <sect2><title>Protocol behavior</title>
+   <para>
+    Most
+    <ulink url="&url.marc21;">MARC21</ulink>
+    records uses the 
+    <ulink url="&url.marc8;">MARC-8</ulink>
+    character set encoding.
+    An application that wishes to display in Latin-1 would use
+    <screen>
+     render; charset=marc8,iso-8859-1
+    </screen>
+   </para>
+   <sect2><title>Z39.50 Protocol behavior</title>
     <para>
      The functions <function>ZOOM_resultset_record</function> and
      <function>ZOOM_resultset_records</function> inspects the client-side
     <para>
      There is a trick, however, in the usage of function
      <function>ZOOM_resultset_records</function> that allows for
-     delayed retrieval (and makes it non-blocking). By passing
+     delayed retrieval (and makes it non-blocking). By using
      a null pointer for <parameter>recs</parameter> you're indicating
      you're not interested in getting records objects
      <emphasis>now</emphasis>.
     </para>
    </sect2>
+   <sect2><title>SRU Protocol behavior</title>
+    <para>
+     The ZOOM driver for SRU treats records returned by a SRU server
+     as if they where Z39.50 records with transfer syntax XML and
+     no element set name or database name.
+    </para>
+   </sect2>
   </sect1>
   <sect1 id="zoom.scan"><title>Scan</title>
    <para>
     is the <literal>ZOOM_scanset</literal> which is a set of terms
     returned by a target.
    </para>
+
+   <para>
+    The Scan interface is Z39.50 only. SRW version 1.0 does not
+    support this.
+   </para>
+
    <synopsis>
-    ZOOM_scanset ZOOM_connection_scan (ZOOM_connection c,
-                                       const char *startterm);
+    ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
+                                      const char *startpqf);
 
     size_t ZOOM_scanset_size(ZOOM_scanset scan);
 
     const char * ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
                                    int *occ, size_t *len);
 
+    const char * ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
+                                           int *occ, size_t *len);
 
     void ZOOM_scanset_destroy (ZOOM_scanset scan);
 
-    const char *ZOOM_scanset_option_get (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);
+    void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
+                                 const char *val);
     </synopsis>
    <para>
     The scan set is created by function
     <function>ZOOM_connection_scan</function> which performs a scan
-    operation on the connection and start term given.
+    operation on the connection using the specified
+    <parameter>startpqf</parameter>.
     If the operation was successful, the size of the scan set can be
-    retrived by a call to <function>ZOOM_scanset_size</function>.
+    retrieved by a call to <function>ZOOM_scanset_size</function>.
     Like result sets, the items are numbered 0,..size-1.
     To obtain information about a particular scan term, call function
     <function>ZOOM_scanset_term</function>. This function takes
     a scan set offset <literal>pos</literal> and returns a pointer
-    to an actual term or <literal>NULL</literal> if non-present.
+    to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
+    non-present.
     If present, the <literal>occ</literal> and <literal>len</literal> 
     are set to the number of occurrences and the length
     of the actual term respectively.
+    <function>ZOOM_scanset_display_term</function> is similar to
+    <function>ZOOM_scanset_term</function> except that it returns
+    the <emphasis>display term</emphasis> 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).
+   </para>
+   <para>
     A scan set may be freed by a call to function
     <function>ZOOM_scanset_destroy</function>.
     Functions <function>ZOOM_scanset_option_get</function> and
     <function>ZOOM_scanset_option_set</function> retrieves and sets
     an option respectively.
    </para>
+
+   <para>
+    The <parameter>startpqf</parameter> is a subset of PQF, namely
+    the Attributes+Term part. Multiple <literal>@attr</literal> can
+    be used. For example to scan in title (complete) phrases:
+    <literallayout>
+     @attr 1=4 @attr 6=2 "science o"
+    </literallayout>
+   </para>
    
    <table frame="top"><title>ZOOM Scan Set Options</title>
     <tgroup cols="3">
      <tbody>
       <row><entry>
         number</entry><entry>Number of Scan Terms requested in next scan.
-        After scan it holds the actual number of terms returend.
+        After scan it holds the actual number of terms returned.
        </entry><entry>10</entry></row>
       <row><entry>
         position</entry><entry>Preferred Position of term in response
      </tbody>
     </tgroup>
    </table>
+  </sect1>
+
+  <sect1 id="zoom.ext"><title>Extended Services</title>
+   <para>
+    ZOOM offers an interface to a subset of the Z39.50 extended services
+    as well as a few privately defined ones:
+   </para>
+   <itemizedlist>
+    <listitem>
+     <para>
+      Z39.50 Item Order (ILL).
+      See <xref linkend="zoom.ext.itemorder"/>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Record Update. This allows a client to insert, modify or delete
+      records.
+      See <xref linkend="zoom.ext.update"/>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Database Create. This a non-standard feature. Allows a client
+      to create a database.
+      See <xref linkend="zoom.ext.dbcreate"/>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Database Drop. This a non-standard feature. Allows a client
+      to delete/drop a database.
+      See <xref linkend="zoom.ext.dbdrop"/>.
+     </para>
+     </listitem>
+    <listitem>
+     <para>
+      Commit operation. This a non-standard feature. Allows a client
+      to commit operations.
+      See <xref linkend="zoom.ext.commit"/>.
+     </para>
+    </listitem>
+    <!-- all the ILL PDU options should go here too -->
+   </itemizedlist>
+   <para>
+    To create an extended service operation a <literal>ZOOM_package</literal>
+    must be created. The operation is a five step operation. The
+    package is created, package is configured by means of options,
+    the package is send, result is inspected (by means of options),
+    the package is destroyed.
+   </para>
+   <synopsis>
+    ZOOM_package ZOOM_connection_package(ZOOM_connection c,
+                                         ZOOM_options options);
+
+    const char *ZOOM_package_option_get(ZOOM_package p,
+                                        const char *key);
+    void ZOOM_package_option_set(ZOOM_package p, const char *key,
+                                 const char *val);
+    void ZOOM_package_send(ZOOM_package p, const char *type);
+
+    void ZOOM_package_destroy(ZOOM_package p);
+   </synopsis>
+   <para>
+    The <function>ZOOM_connection_package</function> creates a
+    package for the connection given using the options specified.
+   </para>
+   <para>
+    Functions <function>ZOOM_package_option_get</function> and
+    <function>ZOOM_package_option_set</function> gets and sets
+    options.
+   </para>
+   <para>
+    <function>ZOOM_package_send</function> sends
+    the package the via connection specified in 
+    <function>ZOOM_connection_package</function>.
+    The <parameter>type</parameter> specifies the actual extended service
+    package type to be sent.
+   </para>
+
+   <table frame="top"><title>Extended Service Common Options</title>
+    <tgroup cols="3">
+     <colspec colwidth="4*" colname="name"></colspec>
+     <colspec colwidth="7*" colname="description"></colspec>
+     <colspec colwidth="3*" colname="default"></colspec>
+     <thead>
+      <row>
+       <entry>Option</entry>
+       <entry>Description</entry>
+       <entry>Default</entry>
+      </row>
+     </thead>
+     <tbody>
+      <row>
+       <entry>package-name</entry>
+       <entry>Extended Service Request package name. Must be specified
+       as part of a request</entry>
+       <entry>none</entry>
+      </row>
+      <row>
+       <entry>user-id</entry>
+       <entry>User ID of Extended Service Package. Is a request option</entry>
+       <entry>none</entry>
+      </row>
+      <row>
+       <entry>function</entry>
+       <entry>
+       Function of package - one of <literal>create</literal>,
+       <literal>delete</literal>, <literal>modify</literal>. Is
+       a request option.
+       </entry>
+       <entry><literal>create</literal></entry>
+      </row>
+      <row>
+       <entry>targetReference</entry>
+       <entry>
+       Target Reference. This is part of the response as returned
+       by the server. Read it after a succesful operation.
+       </entry>
+       <entry><literal>none</literal></entry>
+      </row>
+     </tbody>
+    </tgroup>
+   </table>
+
+   <sect2 id="zoom.ext.itemorder"><title>Item Order</title>
+    <para>
+     For Item Order, type must be set to <literal>itemorder</literal> in
+     <function>ZOOM_package_send</function>.
+    </para>
+
+    <table frame="top"><title>Item Order Options</title>
+     <tgroup cols="3">
+      <colspec colwidth="4*" colname="name"></colspec>
+      <colspec colwidth="7*" colname="description"></colspec>
+      <colspec colwidth="3*" colname="default"></colspec>
+      <thead>
+       <row>
+       <entry>Option</entry>
+       <entry>Description</entry>
+       <entry>Default</entry>
+       </row>
+      </thead>
+      <tbody>
+       <row>
+       <entry>contact-name</entry>
+       <entry>ILL contact name</entry>
+       <entry>none</entry>
+       </row>
+       <row>
+       <entry>contact-phone</entry>
+       <entry>ILL contact phone</entry>
+       <entry>none</entry>
+       </row>
+       <row>
+       <entry>contact-email</entry>
+       <entry>ILL contact email</entry>
+       <entry>none</entry>
+       </row>
+       <row>
+       <entry>itemorder-item</entry>
+       <entry>Position for item (record) requested. An integer</entry>
+       <entry>1</entry>
+       </row>
+      </tbody>
+     </tgroup>
+    </table>
+
+   </sect2>
+
+   <sect2 id="zoom.ext.update"><title>Record Update</title>
+    <para>
+     For Record Update, type must be set to <literal>update</literal> in
+     <function>ZOOM_package_send</function>.
+    </para>
+
+    <table frame="top"><title>Record Update Options</title>
+     <tgroup cols="3">
+      <colspec colwidth="4*" colname="name"></colspec>
+      <colspec colwidth="7*" colname="description"></colspec>
+      <colspec colwidth="3*" colname="default"></colspec>
+      <thead>
+       <row>
+       <entry>Option</entry>
+       <entry>Description</entry>
+       <entry>Default</entry>
+       </row>
+      </thead>
+      <tbody>
+       <row>
+       <entry>action</entry>
+       <entry>
+        The update action. One of 
+        <literal>specialUpdate</literal>,
+        <literal>recordInsert</literal>,
+        <literal>recordReplace</literal>,
+        <literal>recordDelete</literal>,
+        <literal>elementUpdate</literal>.
+       </entry>
+       <entry><literal>specialUpdate</literal></entry>
+       </row>
+       <row>
+       <entry>recordIdOpaque</entry>
+       <entry>Opaque Record ID</entry>
+       <entry>none</entry>
+       </row>
+       <row>
+       <entry>recordIdNumber</entry>
+       <entry>Record ID number</entry>
+       <entry>none</entry>
+       </row>
+       <row>
+       <entry>record</entry>
+       <entry>The record itself</entry>
+       <entry>none</entry>
+       </row>
+       <row>
+       <entry>syntax</entry>
+       <entry>The record syntax (transfer syntax). Is a string that
+        is a known record syntax.
+       </entry>
+       <entry>no syntax</entry>
+       </row>
+       <row>
+       <entry>databaseName</entry>
+       <entry>Database from connection object</entry>
+       <entry>Default</entry>
+       </row>
+      </tbody>
+     </tgroup>
+    </table>
+    
+   </sect2>
+
+   <sect2 id="zoom.ext.dbcreate"><title>Database Create</title>
+    <para>
+     For Database Create, type must be set to <literal>create</literal> in
+     <function>ZOOM_package_send</function>.
+    </para>
+    
+    <table frame="top"><title>Database Create Options</title>
+     <tgroup cols="3">
+      <colspec colwidth="4*" colname="name"></colspec>
+      <colspec colwidth="7*" colname="description"></colspec>
+      <colspec colwidth="3*" colname="default"></colspec>
+      <thead>
+       <row>
+       <entry>Option</entry>
+       <entry>Description</entry>
+       <entry>Default</entry>
+       </row>
+      </thead>
+      <tbody>
+       <row>
+       <entry>databaseName</entry>
+       <entry>Database from connection object</entry>
+       <entry>Default</entry>
+       </row>
+      </tbody>
+     </tgroup>
+    </table>
+   </sect2>
    
+   <sect2 id="zoom.ext.dbdrop"><title>Database Drop</title>
+    <para>
+     For Database Drop, type must be set to <literal>drop</literal> in
+     <function>ZOOM_package_send</function>.
+    </para>
+    
+    <table frame="top"><title>Database Create Options</title>
+     <tgroup cols="3">
+      <colspec colwidth="4*" colname="name"></colspec>
+      <colspec colwidth="7*" colname="description"></colspec>
+      <colspec colwidth="3*" colname="default"></colspec>
+      <thead>
+       <row>
+       <entry>Option</entry>
+       <entry>Description</entry>
+       <entry>Default</entry>
+       </row>
+      </thead>
+      <tbody>
+       <row>
+       <entry>databaseName</entry>
+       <entry>Database from connection object</entry>
+       <entry>Default</entry>
+       </row>
+      </tbody>
+     </tgroup>
+    </table>
+   </sect2>
+   
+   <sect2 id="zoom.ext.commit"><title>Commit Operation</title>
+    <para>
+     For Commit, type must be set to <literal>commit</literal> in
+     <function>ZOOM_package_send</function>.
+    </para>
+   </sect2>
+
+   <sect2><title>Protocol behavior</title>
+    <para>
+     All the extended services are Z39.50-only.
+    </para>
+    <note>
+     <para>
+      The database create, drop and commit services are privately defined
+      operations.
+      Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
+      definitions.
+     </para>
+    </note>
+   </sect2>
   </sect1>
+
   <sect1 id="zoom.options"><title>Options</title>
    <para>
     Most &zoom; objects provide a way to specify options to change behavior.
     From an implementation point of view a set of options is just like
-    an associative array / hash array, etc.
+    an associative array / hash.
    </para>
    <synopsis>
      ZOOM_options ZOOM_options_create (void);
     <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
     A pending event could be a sending a search, receiving a response,
     etc.
-    When an event has occured for one of the connections, this function
+    When an event has occurred for one of the connections, this function
     returns a positive integer <literal>n</literal> denoting that an event
     occurred for connection <literal>cs[n-1]</literal>.
     When no events are pending for the connections, a value of zero is
     To ensure that all outstanding requests are performed call this function
     repeatedly until zero is returned.
    </para>
+   <para>
+    If <function>ZOOM_event</function> returns and returns non-zero, the
+    last event that occurred can be expected.
+   </para>
+   <synopsis>
+    int ZOOM_connection_last_event(ZOOM_connection cs);
+   </synopsis>
+   <para>
+    <function>ZOOM_connection_last_event</function> returns an event type
+    (integer) for the last event.
+   </para>
+
+   <table frame="top"><title>ZOOM Event IDs</title>
+    <tgroup cols="2">
+     <colspec colwidth="4*" colname="name"></colspec>
+     <colspec colwidth="7*" colname="description"></colspec>
+     <thead>
+      <row>
+       <entry>Event</entry>
+       <entry>Description</entry>
+      </row>
+     </thead>
+     <tbody>
+      <row>
+       <entry>ZOOM_EVENT_NONE</entry>
+       <entry>No event has occurred</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_CONNECT</entry>
+       <entry>TCP/IP connect has initiated</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_SEND_DATA</entry>
+       <entry>Data has been transmitted (sending)</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_RECV_DATA</entry>
+       <entry>Data has been received)</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_TIMEOUT</entry>
+       <entry>Timeout</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_UNKNOWN</entry>
+       <entry>Unknown event</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_SEND_APDU</entry>
+       <entry>An APDU has been transmitted (sending)</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_RECV_APDU</entry>
+       <entry>An APDU has been received</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_RECV_RECORD</entry>
+       <entry>A result-set record has been received</entry>
+      </row>
+      <row>
+       <entry>ZOOM_EVENT_RECV_SEARCH</entry>
+       <entry>A search result been received</entry>
+      </row>
+     </tbody>
+    </tgroup>
+   </table>
   </sect1>
  </chapter>