Add class NodaValidationHelper, for now for validating actor

descriptions

src/NodaUncertaintyHelper.php

@@ -7,7 +7,8 @@
 declare(strict_types = 1);
 
 /**
- * Contains static functions for getting IDs for noda entries by various means.
+ * Contains static functions for identifying uncertainty or blocking
+ * completely uncertain inputs for actors, times, and places.
  */
 final class NodaUncertaintyHelper {
 

src/NodaValidationHelper.php

@@ -0,0 +1,64 @@
+<?PHP
+/**
+ * Contains class NodaValidationHelper.
+ *
+ * @author Joshua Ramon Enslin <joshua@museum-digital.de>
+ */
+declare(strict_types = 1);
+
+/**
+ * A class of static functions for validating single fields of noda entities.
+ */
+final class NodaValidationHelper {
+
+    const ACTOR_DESCRIPTION_REQUIRED_DISTINCT_CHARS = 2;
+
+    /**
+     * Validates an actor description for completeness. Of course, only an informed
+     * guess based on the length and character composition of the description can be
+     * made.
+     *
+     * @param string   $description Input descrition.
+     * @param string[] $names       Names of the actor. Optional. Setting this enables
+     *                              checks e.g. to prevent duplicating the actor name
+     *                              as a description.
+     *
+     * @return void
+     */
+    public static function validateActorDescription(string $description, array $names = []):void {
+
+        // Throw error on descriptions that are too short
+        if (\mb_strlen($description) < 10) {
+            throw new MDgenericInvalidInputsException("Author description is too short");
+        }
+
+        // Validate actor description based on character composition.
+
+        $chars = \str_split($description);
+
+        $uniqueChars = array_unique($chars);
+        if (count($uniqueChars) <= self::ACTOR_DESCRIPTION_REQUIRED_DISTINCT_CHARS) {
+            throw new MDgenericInvalidInputsException("There need to be more than " . self::ACTOR_DESCRIPTION_REQUIRED_DISTINCT_CHARS . " distinct characters.");
+        }
+
+        if (!empty($names)) {
+
+            $clearedChars = ['  ' => ' ', ',' => ' ', ';' => ' ', '.' => ' '];
+
+            $namesMerged = implode(' ', $names);
+            $namesMerged = strtr($namesMerged, $clearedChars);
+            $uniqueNames = array_unique(array_diff(explode(' ', $namesMerged), ['']));
+            sort($uniqueNames);
+
+            $descCleared = strtr($description, $clearedChars);
+            $descWords = array_unique(array_diff(explode(' ', $descCleared), ['']));
+            sort($descWords);
+
+            if ($uniqueNames === $descWords) {
+                throw new MDgenericInvalidInputsException("The actor name was simply repeated in the description. This is not enough.");
+            }
+
+        }
+
+    }
+}