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12 <refentry id="pazpar2_protocol">
14 <productname>Pazpar2</productname>
15 <productnumber>&version;</productnumber>
16 <info><orgname>Index Data</orgname></info>
19 <refentrytitle>Pazpar2 protocol</refentrytitle>
20 <manvolnum>7</manvolnum>
21 <refmiscinfo class="manual">Conventions and miscellaneous</refmiscinfo>
25 <refname>pazpar2_protocol</refname>
26 <refpurpose>The webservice protocol of Pazpar2</refpurpose>
30 <title>DESCRIPTION</title>
32 Webservice requests are any that refer to filename "search.pz2". Arguments
33 are GET-style parameters. Argument 'command' is always required and specifies
34 the operation to perform. Any request not recognized as a webservice
35 request is forwarded to the HTTP server specified in the configuration
36 using the proxy setting.
37 This way, a regular webserver can host the user interface (itself dynamic
38 or static HTML), and Ajax-style calls can be used from JS (or any other
39 client-based scripting environment) to interact with the search logic
43 Each command is described in sub sections to follow.
45 <refsect2 id="command-init">
48 Initializes a session.
49 Returns session ID to be used in subsequent requests. If
50 a server ID is given in the Pazpar2 server section, then a
51 that is included in the session ID as suffix after a period (.).
54 If the init command is performed as a HTTP GET request, service
55 and settings from local files are used. The service parameter
56 may chose a particular local service.
59 If the init command is performed as a HTTP POST request and
60 the content-type is text/xml, then the content is XML parsed
61 and treated as service for the session. The root element should be
62 service. Refer to descripton of the
63 <link linkend="service_conf">service</link> format.
64 The posting of a service appeared in Pazpar2 version 1.2.1.
69 search.pz2?command=init
78 <session>2044502273</session>
82 The init command may take a number of setting parameters, similar to
83 the 'settings' command described below. These settings are immediately
84 applied to the new session. Other parameters for init are:
90 If this is defined and the value is non-zero, the session will
91 not use the predefined databases in the configuration; only those
92 specified in the settings parameters (per session databases).
101 If this is defined it specifies a service ID. Makes the session use
102 the service with this ID. If this is setting is omitted, the
103 session will use the unnamed service in the Pazpar2 configuration.
111 <refsect2 id="command-ping">
114 Keeps a session alive. An idle session will time out after one minute.
115 The ping command can be used to keep the session alive absent other
117 It is suggested that any browser client have a simple alarm handler which
118 sends a ping every 50 seconds or so once a session has been initialized.
123 search.pz?command=ping&session=2044502273
134 <refsect2 id="command-settings">
135 <title>settings</title>
137 The settings command applies session-specific settings to one or more
138 databases. A typical function of this is to enable access to
139 restricted resources for registered users, or to set a user- or
140 library-specific username/password to use against a target.
143 Each setting parameter has the form name[target]=value, where name is the
144 name of the setting (e.g. pz:authentication), target is a target ID,
145 or possibly a wildcard, and value is the desired value for the
150 Because the settings command manipulates potentially sensitive
151 information, it is possible to configure Pazpar2 to only allow access
152 to this command from a trusted site -- usually from server-side
153 scripting, which in turn is responsible for authenticating the user,
154 and possibly determining which resources he has access to, etc.
159 As a shortcut, it is also possible to override settings directly in
165 If the settings command is performed as HTTP POST and the content-type
166 is text/xml, then the content is XML parsed and treated as settings -
167 with a format identical to local
168 <link linkend="target_settings">settings files</link>.
169 The posting of settings appeared in Pazpar version 1.2.1.
175 search.pz?command=settings&session=2044502273&pz:allow[search.com:210/db1]=1
186 <refsect2 id="command-search">
187 <title>search</title>
189 Launches a search, parameters:
212 Limits the search to a given set of targets specified by the
213 filter. The filter consists a comma separated list of
214 <emphasis>setting</emphasis>+<emphasis>operator</emphasis>+<emphasis>args</emphasis>
215 pairs. The <emphasis>setting</emphasis> is a Pazpar2 setting
216 (such as <literal>pz:id</literal>).
217 The <emphasis>operator</emphasis> is either
218 <literal>=</literal> (string match)
219 or <literal>~</literal> (substring match).
220 The <emphasis>args</emphasis> is a list of values separated
221 by <literal>|</literal> (or , one of the values).
222 The idea is that only targets with a setting matching one of
223 the values given will be included in the search.
231 Narrows the search by one or more fields (typically facets).
232 The limit is sequence of one or more
233 <emphasis>name</emphasis>=<emphasis>args</emphasis> pairs separated
234 by comma. The <emphasis>args</emphasis> is a list of values
235 separated by vertical bar (<literal>|</literal>).
236 The meaning of <literal>|</literal> is alternative, ie OR .
237 A value that contains a comma (<literal>,</literal>),
238 a vertical bar (<literal>|</literal>) or
239 backslash itself must be preceded by backslash (<literal>\</literal>).
240 The <link linkend="limitmap">pz:limitmap</link> configuration
241 item defines how the searches are mapped to a database.
246 <term>startrecs</term>
249 Specifies the first record to retrieve from each target.
250 The first record in a result set for a target is numbered 0, next
251 record is numbered 2. By default maxrecs is 0.
259 Specifies the maximum number of records to retrieve from each
260 target. The default value is 100. This setting has same meaning
261 as per-target setting pz:maxrecs . If pz:maxrecs is set, it takes
262 precedence over argument maxrecs.
270 Specifies sort criteria. The argument is a comma-separated list
271 (no whitespace allowed) of sort fields, with the highest-priority
272 field first. A sort field may be followed by a colon followed by
273 the number '0' (decreasing) or '1' (increasing). Default
274 sort order is decreasing.
275 Sort field names can be any field name designated as a sort field
276 in the pazpar2.cfg file, or the special names 'relevance' and
280 If not specified here or as
281 <link linkend="sort-default">sort-default"</link>
282 in pazpar2.cfg, Pazpar2 will default to the built-in
286 Having sort criteria at search is important for targets that
287 supports native sorting in order to get best results. Pazpar2
288 will trigger a new search if search criteria changes from Pazpar2
289 to target-based sorting or visa-versa.
295 <term>mergekey</term>
298 Sets mergekey for this search and rest of session, or until
299 another mergekey is given for show/search. The mergekey value is a
300 comma separated list with one or more names as they appear
301 in the service description equivalent to
302 <literal>mergekey="optional"</literal> inside a metadata element.
303 If the empty string is given for mergekey it is disabled
304 and rest of session will use the default mergekey from service
308 This facility, "dynamic mergekey", appeared in Pazpar2 version
318 Sets rank method this search and rest of session, or until
319 another rank is given for show/search. The rank value is a
320 comma separated list of pairs field=value pairs. The
321 format is the same as
322 <xref linkend="metadata-rank">rank</xref> for a metadata element.
323 If the empty string is given for rank it is disabled
324 and rest of session will use the default rank from metadata or
328 This facility, "dynamic ranking", appeared in Pazpar2 version
340 search.pz2?session=2044502273&command=search&query=computer+science
352 <refsect2 id="command-stat">
355 Provides status information about an ongoing search. Parameters:
372 search.pz2?session=2044502273&command=stat
377 <activeclients>3</activeclients>
378 <hits>7</hits> -- Total hitcount
379 <records>7</records> -- Total number of records fetched in last query
380 <clients>1</clients> -- Total number of associated clients
381 <unconnected>0</unconnected> -- Number of disconnected clients
382 <connecting>0</connecting> -- Number of clients in connecting state
383 <initializing>0</initializing> -- Number of clients initializing
384 <searching>0</searching> -- ... searching
385 <presenting>0</presenting> -- ... presenting
386 <idle>1</idle> -- ... idle (not doing anything)
387 <failed>0</failed> -- ... Connection failed
388 <error>0</error> -- ... Error was produced somewhere
394 <refsect2 id="command-show">
397 Shows records retrieved. Parameters:
411 <para>First record to show - 0-indexed.</para>
419 Number of records to show If omitted, 20 is used.
428 If block is set to 1, the command will hang until there are records
429 ready to display. Use this to show first records rapidly without
430 requiring rapid polling.
439 Specifies sort criteria. The argument is a comma-separated list
440 (no whitespace allowed) of sort fields, with the highest-priority
441 field first. A sort field may be followed by a colon followed by
442 the number '0' (decreasing) or '1' (increasing). Default
443 sort order is decreasing.
444 Sort field names can be any field name designated as a sort field
445 in the pazpar2.cfg file, or the special names 'relevance' and
449 If not specified here or as
450 <link linkend="sort-default">sort-default"</link>
451 in pazpar2.cfg, pazpar2 will default to the built-in
455 Having sort criteria at search is important for targets that
456 supports native sorting in order to get best results. pazpar2
457 will trigger a new search if search criteria changes from pazpar2
458 to target-based sorting.
461 For targets where If <link linkend="pzsortmap">pz:sortmap</link>
462 is defined, a sort operation will be executed (possibly including
463 extending the search).
469 <term>mergekey</term>
472 Sets mergekey for this show and rest of session, or until
473 another mergekey is given for show/search. The mergekey value is a
474 comma separated list with one or more names as they appear
475 in the service description equivalent to
476 <literal>mergekey="optional"</literal> inside a metadata element.
477 If the empty string is given for mergekey it is disabled
478 and rest of session will use the default mergekey from service
482 This facility, "dynamic mergekey", appeared in Pazpar2 version
492 Sets rank method this show and rest of session, or until
493 another rank is given for show/search. The rank value is a
494 comma separated list of pairs field=value pairs. The
495 format is the same as
496 <xref linkend="metadata-rank">rank</xref> for a metadata element.
497 If the empty string is given for rank it is disabled
498 and rest of session will use the default rank from metadata or
502 This facility, "dynamic ranking", appeared in Pazpar2 version
509 <term>snippets</term>
512 If specified and set to 1 data will include snippets marked
513 with <match> tags. Otherwise snippets will not be included.
516 This facility, "snippets", appeared in Pazpar2 version
527 search.pz2?session=2044502273&command=show&start=0&num=2&sort=title:1
533 <activeclients>3</activeclients> -- How many clients are still working
534 <merged>6</merged> -- Number of merged records
535 <total>7</total> -- Total of all hitcounts
536 <start>0</start> -- The start number you requested
537 <num>2</num> -- Number of records retrieved
539 <md-title>How to program a computer, by Jack Collins</md-title>
540 <count>2</count> -- Number of merged records
541 <recid>6</recid> -- Record ID for this record
545 Computer processing of dynamic images from an Anger scintillation camera :
546 the proceedings of a workshop /
555 <refsect2 id="command-record">
556 <title>record</title>
558 Retrieves a detailed record. Unlike the
559 <link linkend="command-show">show</link> command, this command
560 returns metadata records before merging takes place. Parameters:
576 record ID as provided by the
577 <link linkend="command-show">show</link> command.
586 This optional parameter is an integer which, when given, makes
587 Pazpar2 return the original record for a specific target.
588 The record set from first target is numbered 0,
589 second record set is numbered 1, etc.
590 The nativesyntax setting, as usual, is used to determine how to
591 create XML from the original record - unless parameter
592 <literal>binary</literal> is given in which the record is
593 fetched as "raw" from ZOOM C (raw, original record).
596 When offset/checksum is not given, the Pazpar2 metadata for the record
597 is returned and with metadata for each targets' data specified
598 in a 'location' list.
604 <term>checksum</term>
607 This optional parameter is a string which, when given, makes
608 Pazpar2 return the original record for a specific target. The
609 checksum is returned as attribtue 'checksum' in element
610 'location' for show command and record command (when checksum
611 and offset is NOT given).
612 The nativesyntax setting, as usual, is used to determine how to
613 create XML from the original record - unless parameter
614 <literal>binary</literal> is given in which the record is
615 fetched as "raw" from ZOOM C (raw, original record).
618 When offset/checksum is not given, the Pazpar2 metadata for the record
619 is returned and with metadata for each targets' data specified
620 in a 'location' list.
627 <term>nativesyntax</term>
630 This optional parameter can be used to override pz:nativesyntax
631 as given for the target. This allow an alternative nativesyntax
632 to be used for original records (see parameteroffset above).
641 This optional parameter is the record syntax used for raw
642 transfer (i.e. when offset is specified). If syntax is not given,
643 but offset is used, the value of pz:requestsyntax is used.
652 This optional parameter is the element set name used to retrieval
653 of a raw record (i.e. when offset is specified).
654 If esn is not given, but offset is used, the value of pz:elements
664 This optional parameter enables "binary" response for retrieval
665 of a original record (i.e. when offset is specified). For binary
666 response the record by default is fetched from ZOOM C using
667 the "raw" option or by parameter nativesyntax if given.
673 <term>snippets</term>
676 If specified and set to 1 data will include snippets marked
677 with <match> tags. Otherwise snippets will not be included.
680 This facility, "snippets", appeared in Pazpar2 version
691 search.pz2?session=605047297&command=record&id=3
699 The Puget Sound Region : a portfolio of thematic computer maps /
701 <md-date>1974</md-date>
702 <md-author>Mairs, John W.</md-author>
703 <md-subject>Cartography</md-subject>
709 <refsect2 id="command-termlist">
710 <title>termlist</title>
712 Retrieves term list(s). Parameters:
727 comma-separated list of termlist names. If omitted,
728 all termlists are returned.
736 maximum number of entries to return - default is 15.
745 search.pz2?session=2044502273&command=termlist&name=author,subject
750 <activeclients>3</activeclients>
753 <name>Donald Knuth</name>
754 <frequency>10</frequency>
757 <name>Robert Pirsig</name>
758 <frequency>2</frequency>
761 <list name="subject">
763 <name>Computer programming</name>
764 <frequency>10</frequency>
772 For the special termlist name "xtargets", results
773 are returned about the targets which have returned the most hits.
774 The 'term' subtree has additional elements,
775 specifically a state and diagnostic field (in the example below, a
776 target ID is returned in place of 'name'.
777 This may or may not change later.
783 <name>library2.mcmaster.ca</name>
784 <frequency>11734</frequency> -- Number of hits
785 <state>Client_Idle</state> -- See the description of 'bytarget' below
786 <diagnostic>0</diagnostic> -- Z39.50 diagnostic codes
793 <refsect2 id="command-bytarget">
794 <title>bytarget</title>
796 Returns information about the status of each active client. Parameters:
812 search.pz2?session=605047297&command=bytarget&id=3
821 <id>z3950.loc.gov/voyager/</id>
823 <diagnostic>0</diagnostic>
824 <records>65</records>
825 <state>Client_Presenting</state>
827 <!-- ... more target nodes below as necessary -->
831 The following client states are defined: Client_Connecting,
832 Client_Connected, Client_Idle, Client_Initializing, Client_Searching,
833 Client_Searching, Client_Presenting, Client_Error, Client_Failed,
834 Client_Disconnected, Client_Stopped, Client_Continue.
838 <refsect2 id="command-service">
839 <title>service</title>
841 Returns service definition (XML). Parameters:
854 The service command appeared in Pazpar2 version 1.6.32
859 <title>SEE ALSO</title>
863 <refentrytitle>pazpar2</refentrytitle>
864 <manvolnum>8</manvolnum>
868 Pazpar2 Configuration:
870 <refentrytitle>pazpar2_conf</refentrytitle>
871 <manvolnum>5</manvolnum>
877 <!-- Keep this comment at the end of the file