Parse Blacklight's JSON representation of MaRC records.

find_marc_field.php

<?php
/**
 * Functions for treating (blacklight-based) Josiah as an API.
 */

namespace ocra\josiah;

/**
 * Find a field (and optionally subfield) in the JSONified MaRCXML record.
 *
 * @return Array|string
 */
function find_marc_field($marcjson, $field, $subfield=null, $ind1 = false, $ind2 = false) {
    foreach ( $marcjson->fields as $fld ) {
        if ( property_exists($fld, $field) ) {
            if ( !$ind1 || $ind1 == $fld->$field->ind1 )
                if ( !$ind2 || $ind2 == $fld->$field->ind2 )
                    $foutp = $fld->$field;
            break;
        }
    }
    
    if ( !isset($foutp) ) return false;
    
    if ( !is_null($subfield) ) {
        foreach ( $foutp->subfields as $sf ) {
            if ( array_key_exists($subfield, $sf) ) {
                return $sf->$subfield;
            }
        }
        return false;
    }
    
    return $foutp;
}

/**
 * Return all fields (or field/subfield pairs) in a JSONified MaRCXML record.
 *
 * @return Array
 */
function find_marc_field_multi($marcjson, $field, $subfield=null, $ind1 = false, $ind2 = false) {
    $fields = array();
    foreach ( $marcjson->fields as $fld ) {
        if ( property_exists($fld, $field) ) {
            if ( !$ind1 || $ind1 == $fld->$field->ind1 )
                if ( !$ind2 || $ind2 == $fld->$field->ind2 )
                    array_push($fields, $fld->$field);
        }
    }
    
    if ( !is_null($subfield) ) {
        $sfields = array();
        foreach ( $fields as $fld ) {
            foreach ( $fld->subfields as $sf ) {
                if ( array_key_exists($subfield, $sf) ) {
                    array_push($sfields, $sf->$subfield);
                }
            }
        }
        return $sfields;
    }
    
    return $fields;
}