2 files changed, 78 insertions, 39 deletions

diff --git a/classes/IsisFinder.php b/classes/IsisFinder.php
index e4f228d..26430c6 100644
--- a/classes/IsisFinder.php
+++ b/classes/IsisFinder.php
@@ -17,22 +17,13 @@ class IsisFinder extends IsisConnector {
    *   Next repetition entry and result.
    */
   public function nextRepetition($entry = 1, $field) {
-    $entry--;
-
-    // Query database.
-    do {
-      $result = $this->read(++$entry);
-      if ($entry == $entries) {
-        break;
+    foreach(new IsisEntryIterator($this, $entry) as $entry => $result) {
+      if (count($this->getValues($field)) >= 2) {
+        return array($entry, $result);
       }
-      $values = $this->getValues($field);
-    } while (count($values) < 2);
-
-    if (count($values) < 2) {
-      return FALSE;
     }
 
-    return array($entry, $result);
+    return FALSE;
   }
 
   /**
@@ -48,22 +39,13 @@ class IsisFinder extends IsisConnector {
    *   Next occurrence.
    */
   public function nextField($entry = 1, $field) {
-    $entry--;
-
-    // Query database.
-    do {
-      $result = $this->read(++$entry);
-      if ($entry == $entries) {
-        break;
+    foreach(new IsisEntryIterator($this, $entry) as $entry => $result) {
+      if (count($this->getValues($field)) > 0) {
+        return array($entry, $result);
       }
-      $values = $this->getValues($field);
-    } while (empty($values));
-
-    if (empty($values)) {
-      return FALSE;
     }
 
-    return array($entry, $result);
+    return FALSE;
   }
 
   /**
@@ -82,22 +64,13 @@ class IsisFinder extends IsisConnector {
    *   Next occurrence.
    */
   public function nextSubfield($entry = 1, $field, $subfield) {
-    $entry--;
-
-    // Query database.
-    do {
-      $result = $this->read(++$entry);
-      if ($entry == $entries) {
-        break;
+    foreach(new IsisEntryIterator($this, $entry) as $entry => $result) {
+      if ($this->hasSubfieldInRows($field, $subfield) !== FALSE) {
+        return array($entry, $result);
       }
-      $has = $this->hasSubfieldInRows($field, $subfield);
-    } while ($has === FALSE);
-
-    if (!$this->hasSubfield($field, $subfield, $has)) {
-      return FALSE;
     }
 
-    return array($entry, $result);
+    return FALSE;
   }
 
   /**
diff --git a/classes/iterators/IsisEntryIterator.php b/classes/iterators/IsisEntryIterator.php
new file mode 100644
index 0000000..6a1d72c
--- /dev/null
+++ b/classes/iterators/IsisEntryIterator.php
@@ -0,0 +1,66 @@
+<?php
+
+/**
+ * Isis entry iterator. Iterates over all entries in
+ * the database.
+ */
+class IsisEntryIterator implements Iterator
+{
+  private $start;
+  private $entry;
+  private $entries;
+
+  /**
+   * Constructor.
+   *
+   * @param $class
+   *   Instance of IsisConnector or child class.
+   *
+   * @param $entry
+   *   Start entry number to iterate from.
+   */ 
+  public function __construct($class, $entry = 1) {
+    // Read the first value.
+    $class->read($entry);
+
+    // Setup.
+    $this->class   = $class;
+    $this->entry   = $this->start = $entry;
+    $this->entries = $class->entries;
+  }
+
+  /**
+   * Rewind the Iterator to the first element.
+   */
+  function rewind() {
+    $this->entry = $this->start;
+  }
+
+  /**
+   * Return the key of the current element.
+   */
+  function key() {
+    return $this->entry;
+  }
+
+  /**
+   * Return the current element.
+   */
+  function current() {
+    return $this->class->result;
+  }
+
+  /**
+   * Move forward to next element.
+   */
+  function next() {
+    $this->class->read(++$this->entry);
+  }
+
+  /**
+   * Check if there is a current element after calls to rewind() or next().
+   */
+  function valid() {
+    return $this->entry <= $this->entries;
+  }  
+}