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Net-Z3950-FOLIO-1.3
River stage zero No dependents
++
/ Net::Z3950::FOLIO::Config

NAME

Net::Z3950::FOLIO::Config - configuration file for the FOLIO Z39.50 gateway

SYNOPSIS

  {
    "okapi": {
      "url": "https://folio-snapshot-okapi.dev.folio.org",
      "tenant": "${OKAPI_TENANT-indexdata}"
    },
    "login": {
      "username": "diku_admin",
      "password": "${OKAPI_PASSWORD}"
    },
    "indexMap": {
      "1": "author",
      "7": "identifiers/@value/@identifierTypeId=\"8261054f-be78-422d-bd51-4ed9f33c3422\"",
      "4": "title",
      "12": {
        "cql": "hrid",
        "relation": "==",
        "omitSortIndexModifiers": [ "missing", "case" ]
      },
      "21": "subject",
      "1016": "author,title,hrid,subject"
    },
    "graphqlQuery": "instances.graphql-query",
    "queryFilter": "source=marc",
    "chunkSize": 5,
    "fieldMap": {
      "title": "245$a",
      "author": "100$a"
    }
  }

DESCRIPTION

The FOLIO Z39.50 gateway z2folio is configured by a single file, named on the command-line, and expressed in JSON. This file specifies how to connect to FOLIO, how to log in, and how to translate its instance records into MARC.

The structure of the file is pretty simple. There are several top-level section, each described in its own section below, and each of them an object with several keys that can exist in it.

If any string value contains sequences of the form ${NAME}, they are each replaced by the values of the corresponding environment variables $NAME, providing a mechanism for injecting values into the condfiguration. This is useful if, for example, it is necessary to avoid embedding authentication secrets in the configuration file.

When substituting environment variables, the bash-like fallback syntax ${NAME-VALUE} is recognised. This evaluates to the value of the environment variable $NAME when defined, falling back to the constant value VALUE otherwise. In this way, the configuration can include default values which may be overridden with environment variables.

okapi

Contains three elements (two mandatory, one optional), all with string values:

url

The full URL to the Okapi server that provides the gateway to the FOLIO installation.

graphqlUrl (optional)

Usually, the main Okapi URL is used for all interaction with FOLIO: logging in, searching, retrieving records, etc. When the optional =graphqlUrl configuration entry is provided, it is used for GraphQL queries only. This provides a way of "side-loading" mod-graphql, which is useful in at least two situations: when the FOLIO snapshot services are unavailable (since the production services do not presently =included mod-graphql); and when you need to run against a development =version of mod-graphql so you can make changes to its behaviour.

tenant

The name of the tenant within that FOLIO installation whose inventory model should be queried.

login

Contains two elements, both with string values:

username

The name of the user to log in as, unless overridden by authentication information in the Z39.50 init request.

password

The corresponding password, unless overridden by authentication information in the Z39.50 init request.

chunkSize

An integer specifying how many records to fetch from FOLIO with each search. This can be tweaked to tune performance. Setting it too low will result in many requests with small numbers of records returned each time; setting it too high will result in fetching and decoding more records than are actually wanted.

indexMap

Contains any number of elements. The keys are the numbers of BIB-1 use attributes, and the corresponding values contain instructions about the indexes in the FOLIO instance record to map those access-points to. The key default is special, and is used for terms where no BIB-1 use attribute is specified.

Each value may be either a string, in which case it is interpreted as a CQL index to map to (see below for details), or an object. When the object version is used, that object's cql member contains the CQL index mapping (see below), and any of the following additional members may also be included:

omitSortIndexModifiers

A bug in FOLIO's CQL query interpreter means that for some indexes, query translation will fail if a sort-specification is provided that requests certain valid behaviours, e.g. a case-sensitive search on the HRID index. To work around this until it's fixed, an index's omitSortIndexModifiers allows you to specify a list of the index-modifier types that they do not support, so that the server can omit those qualifiers when creating sort-specifications. The valid index-modifier types are missing, relation and case.

relation

If specified, the value is the relation that should be used instead of = by default when searching in this index. This is useful mostly for defaulting to the strict-equality relation == for indexes whose values are atomic, such as identifiers.

Each cql value (or string value when the object form is not used) may be a comma-separated list of multiple CQL indexes to be queried.

Each CQL index specified as a value, or as one of the comma-separated components of a value, may contain a forward slash. If it does, then the part before the slash is used as the actual index name, and the part after the slash as a CQL relation modifier. For example, if the index map contains

  "999": "foo/bar=quux"

Then a search for @attr 1=9 thrick will be translated to the CQL query foo =/bar=quux thrick.

graphqlQuery

The name of a file, in the same directory as the main configuration file, which contains the text of the GraphQL query to be used to obtain the instance, holdings and item data pertaining to the records identified by the CQL query.

queryFilter

If specified, this is a CQL query which is automatically anded with every query submitted by the client, so it acts as a filter allowing through only records that satisfy it. This might be used, for example, to specify source=marc to limit search result to only to those FOLIO instance records that were translated from MARC imports.

SEE ALSO

The z2folio script conveniently launches the server.
Net::Z3950::FOLIO is the library that consumes this configuration.
The Net::Z3950::SimpleServer handles the Z39.50 service.

AUTHOR

Mike Taylor, <mike@indexdata.com>

COPYRIGHT AND LICENSE

Copyright (C) 2018 The Open Library Foundation

This software is distributed under the terms of the Apache License, Version 2.0. See the file "LICENSE" for more information.