refactor: Add constants for the three record types

Author: danmichaelo

src/Marc21.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace Scriptotek\Marc;
+
+class Marc21
+{
+    // MARC21 record types
+    const AUTHORITY = 'Authority';
+    const BIBLIOGRAPHIC = 'Bibliographic';
+    const HOLDINGS = 'Holdings';
+}

src/Record.php

@@ -60,6 +60,14 @@ public static function fromString($data)
      * Determine if record is a bibliographic, authority or holdings record
      *************************************************************************/
 
+    /**
+     * Get the record type based on the value of LDR/6. Returns any of
+     * the Marc21::BIBLIOGRAPHIC, Marc21::AUTHORITY or Marc21::HOLDINGS
+     * constants.
+     *
+     * @return string
+     * @throws ErrorException
+     */
     public function getType()
     {
         $leader = $this->record->getLeader();
@@ -80,14 +88,14 @@ public function getType()
             case 'p': // Mixed materials
             case 'r': // Three-dimensional artifact or naturally occurring object
             case 't': // Manuscript language material
-                return 'Bibliographic';
+                return Marc21::BIBLIOGRAPHIC;
             case 'z':
-                return 'Authority';
+                return Marc21::AUTHORITY;
             case 'u': // Unknown
             case 'v': // Multipart item holdings
             case 'x': // Single-part item holdings
             case 'y': // Serial item holdings
-                return 'Holdings';
+                return Marc21::HOLDINGS;
             default:
                 throw new \ErrorException('Unknown record type.');
         }

tests/RecordTest.php

@@ -1,5 +1,6 @@
 <?php
 
+use Scriptotek\Marc\Marc21;
 use Scriptotek\Marc\Record;
 
 class RecordTest extends \PHPUnit_Framework_TestCase
@@ -69,7 +70,7 @@ public function testRecordTypeBiblio()
           </record>';
 
         $record = Record::fromString($source);
-        $this->assertEquals('Bibliographic', $record->type);
+        $this->assertEquals(Marc21::BIBLIOGRAPHIC, $record->type);
     }
 
     public function testRecordTypeAuthority()
@@ -80,6 +81,6 @@ public function testRecordTypeAuthority()
          </record>';
 
         $record = Record::fromString($source);
-        $this->assertEquals('Authority', $record->type);
+        $this->assertEquals(Marc21::AUTHORITY, $record->type);
     }
 }