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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 <link linkend="sort-default">sort-default"</link>
281 in pazpar2.cfg, Pazpar2 will default to the built-in 'relevance' ranking.
284 Having sort criteria at search is important for targets that
285 supports native sorting in order to get best results. Pazpar2
286 will trigger a new search if search criteria changes from Pazpar2
287 to target-based sorting or visa-versa.
297 search.pz2?session=2044502273&command=search&query=computer+science
309 <refsect2 id="command-stat">
312 Provides status information about an ongoing search. Parameters:
329 search.pz2?session=2044502273&command=stat
334 <activeclients>3</activeclients>
335 <hits>7</hits> -- Total hitcount
336 <records>7</records> -- Total number of records fetched in last query
337 <clients>1</clients> -- Total number of associated clients
338 <unconnected>0</unconnected> -- Number of disconnected clients
339 <connecting>0</connecting> -- Number of clients in connecting state
340 <initializing>0</initializing> -- Number of clients initializing
341 <searching>0</searching> -- ... searching
342 <presenting>0</presenting> -- ... presenting
343 <idle>1</idle> -- ... idle (not doing anything)
344 <failed>0</failed> -- ... Connection failed
345 <error>0</error> -- ... Error was produced somewhere
351 <refsect2 id="command-show">
354 Shows records retrieved. Parameters:
368 <para>First record to show - 0-indexed.</para>
376 Number of records to show If omitted, 20 is used.
385 If block is set to 1, the command will hang until there are records
386 ready to display. Use this to show first records rapidly without
387 requiring rapid polling.
393 <term>mergekey</term>
396 Sets mergekey for this search and rest of session, or until
397 another mergekey is given for show/search. The mergekey value is a
398 comma separated list with one or more names as they appear
399 in the service description equivalent to
400 <literal>mergekey="optional"</literal> inside a metadata element.
401 If the empty string is given for mergekey it is disabled
402 and rest of session will use the default mergekey from service
406 This facility, "dynamic mergekey", appeared in Pazpar2 version
416 Specifies sort criteria. The argument is a comma-separated list
417 (no whitespace allowed) of sort fields, with the highest-priority
418 field first. A sort field may be followed by a colon followed by
419 the number '0' (decreasing) or '1' (increasing). Default
420 sort order is decreasing.
421 Sort field names can be any field name designated as a sort field
422 in the pazpar2.cfg file, or the special names 'relevance' and
425 If not specified here or as <link linkend="sort-default">sort-default"</link>
426 in pazpar2.cfg, pazpar2 will default to the built-in 'relevance' ranking.
428 Having sort criteria at search is important for targets that
429 supports native sorting in order to get best results. pazpar2
430 will trigger a new search if search criteria changes from pazpar2
431 to target-based sorting.
435 For targets where If <link linkend="pzsortmap">pz:sortmap</link>
436 is defined, a sort operation will be executed (possibly including
437 extending the search).
443 <term>mergekey</term>
446 Sets mergekey for this show and rest of session, or until
447 another mergekey is given for show/search. The mergekey value is a
448 comma separated list with one or more names as they appear
449 in the service description equivalent to
450 <literal>mergekey="optional"</literal> inside a metadata element.
451 If the empty string is given for mergekey it is disabled
452 and rest of session will use the default mergekey from service
456 This facility, "dynamic mergekey", appeared in Pazpar2 version
467 search.pz2?session=2044502273&command=show&start=0&num=2&sort=title:1
473 <activeclients>3</activeclients> -- How many clients are still working
474 <merged>6</merged> -- Number of merged records
475 <total>7</total> -- Total of all hitcounts
476 <start>0</start> -- The start number you requested
477 <num>2</num> -- Number of records retrieved
479 <md-title>How to program a computer, by Jack Collins</md-title>
480 <count>2</count> -- Number of merged records
481 <recid>6</recid> -- Record ID for this record
485 Computer processing of dynamic images from an Anger scintillation camera :
486 the proceedings of a workshop /
495 <refsect2 id="command-record">
496 <title>record</title>
498 Retrieves a detailed record. Unlike the
499 <link linkend="command-show">show</link> command, this command
500 returns metadata records before merging takes place. Parameters:
516 record ID as provided by the
517 <link linkend="command-show">show</link> command.
526 This optional parameter is an integer which, when given, makes
527 Pazpar2 return the original record for a specific target.
528 The record set from first target is numbered 0,
529 second record set is numbered 1, etc.
530 The nativesyntax setting, as usual, is used to determine how to
531 create XML from the original record - unless parameter
532 <literal>binary</literal> is given in which the record is
533 fetched as "raw" from ZOOM C (raw, original record).
536 When offset/checksum is not given, the Pazpar2 metadata for the record
537 is returned and with metadata for each targets' data specified
538 in a 'location' list.
544 <term>checksum</term>
547 This optional parameter is a string which, when given, makes
548 Pazpar2 return the original record for a specific target. The
549 checksum is returned as attribtue 'checksum' in element
550 'location' for show command and record command (when checksum
551 and offset is NOT given).
552 The nativesyntax setting, as usual, is used to determine how to
553 create XML from the original record - unless parameter
554 <literal>binary</literal> is given in which the record is
555 fetched as "raw" from ZOOM C (raw, original record).
558 When offset/checksum is not given, the Pazpar2 metadata for the record
559 is returned and with metadata for each targets' data specified
560 in a 'location' list.
567 <term>nativesyntax</term>
570 This optional parameter can be used to override pz:nativesyntax
571 as given for the target. This allow an alternative nativesyntax
572 to be used for original records (see parameteroffset above).
581 This optional parameter is the record syntax used for raw
582 transfer (i.e. when offset is specified). If syntax is not given,
583 but offset is used, the value of pz:requestsyntax is used.
592 This optional parameter is the element set name used to retrieval
593 of a raw record (i.e. when offset is specified).
594 If esn is not given, but offset is used, the value of pz:elements
604 This optional parameter enables "binary" response for retrieval
605 of a original record (i.e. when offset is specified). For binary
606 response the record by default is fetched from ZOOM C using
607 the "raw" option or by parameter nativesyntax if given.
617 search.pz2?session=605047297&command=record&id=3
625 The Puget Sound Region : a portfolio of thematic computer maps /
627 <md-date>1974</md-date>
628 <md-author>Mairs, John W.</md-author>
629 <md-subject>Cartography</md-subject>
635 <refsect2 id="command-termlist">
636 <title>termlist</title>
638 Retrieves term list(s). Parameters:
653 comma-separated list of termlist names. If omitted,
654 all termlists are returned.
662 maximum number of entries to return - default is 15.
671 search.pz2?session=2044502273&command=termlist&name=author,subject
676 <activeclients>3</activeclients>
679 <name>Donald Knuth</name>
680 <frequency>10</frequency>
683 <name>Robert Pirsig</name>
684 <frequency>2</frequency>
687 <list name="subject">
689 <name>Computer programming</name>
690 <frequency>10</frequency>
698 For the special termlist name "xtargets", results
699 are returned about the targets which have returned the most hits.
700 The 'term' subtree has additional elements,
701 specifically a state and diagnostic field (in the example below, a
702 target ID is returned in place of 'name'.
703 This may or may not change later.
709 <name>library2.mcmaster.ca</name>
710 <frequency>11734</frequency> -- Number of hits
711 <state>Client_Idle</state> -- See the description of 'bytarget' below
712 <diagnostic>0</diagnostic> -- Z39.50 diagnostic codes
719 <refsect2 id="command-bytarget">
720 <title>bytarget</title>
722 Returns information about the status of each active client. Parameters:
738 search.pz2?session=605047297&command=bytarget&id=3
747 <id>z3950.loc.gov/voyager/</id>
749 <diagnostic>0</diagnostic>
750 <records>65</records>
751 <state>Client_Presenting</state>
753 <!-- ... more target nodes below as necessary -->
757 The following client states are defined: Client_Connecting,
758 Client_Connected, Client_Idle, Client_Initializing, Client_Searching,
759 Client_Searching, Client_Presenting, Client_Error, Client_Failed,
760 Client_Disconnected, Client_Stopped, Client_Continue.
766 <title>SEE ALSO</title>
770 <refentrytitle>pazpar2</refentrytitle>
771 <manvolnum>8</manvolnum>
775 Pazpar2 Configuration:
777 <refentrytitle>pazpar2_conf</refentrytitle>
778 <manvolnum>5</manvolnum>
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