CXIII. YAZ functions
This extension offers a PHP interface to the YAZ toolkit that implements the Z39.50 Protocol for Information Retrieval. With this extension you can easily implement a Z39.50 origin (client) that searches or scans Z39.50 targets (servers) in parallel.
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.
Compile YAZ (ANSI/NISO Z39.50 support) and install it. Build PHP with your favourite modules and add option --with-yaz[=DIR]. Your task is roughly the following:
If you are using YAZ as a shared extension, add (or uncomment) the following line in php.ini on Unix:
On Windows, php_yaz.dll depend on yaz.dll. You'll find yaz.dll in sub directory dlls in the Win32 zip archive. Copy yaz.dll to a directory in your PATH environment (c:\winnt\system32 or c:\windows\system32).
Note: The above problem is solved in version 2.0 of YAZ.
The behaviour of these functions is affected by settings in php.ini.
Table 1. YAZ configuration options
PHP/YAZ keeps track of connections with targets (Z-Associations). A resource represents a connection to a target.
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 host.
- Table of Contents
- yaz_addinfo -- Returns additional error information
- yaz_ccl_conf -- Configure CCL parser
- yaz_ccl_parse -- Invoke CCL Parser
- yaz_close -- Close YAZ connection
- yaz_connect -- Prepares for a connection to a Z39.50 target (server).
- yaz_database -- Specifies the databases within a session
- yaz_element -- Specifies Element-Set Name for retrieval
- yaz_errno -- Returns error number
- yaz_error -- Returns error description
- yaz_get_option -- Returns value of option for connection
- yaz_hits -- Returns number of hits for last search
- yaz_itemorder -- Prepares for Z39.50 Item Order with an ILL-Request package
- yaz_present -- Prepares for retrieval (Z39.50 present).
- yaz_range -- Specifies the maximum number of records to retrieve
- yaz_record -- Returns a record
- yaz_scan_result -- Returns Scan Response result
- yaz_scan -- Prepares for a scan
- yaz_schema -- Specifies schema for retrieval.
- yaz_search -- Prepares for a search
- yaz_set_option -- Sets one or more options for connection
- yaz_sort -- Sets sorting criteria
- yaz_syntax -- Specifies the preferred record syntax for retrieval.
- yaz_wait -- Wait for Z39.50 requests to complete