Optionally recursive $geometry->getComponents

lib/geometry/Collection.class.php

@@ -34,10 +34,56 @@ public function __construct($components = array()) {
   /**
    * Returns Collection component geometries
    *
+   * If no parameters are provided it simply returns the array of components stored in this collection
+   * instance.  If the types parameter is provided and contains a list of valid geometries as listed in
+   * geoPHP::geometryTypes() then the list of components will be further broken down to match the types
+   * provided.  For example, if $geometry->getComponents('Point') is called, then the collection
+   * will be recursively broken down until all geometries have been broken down into points.  A common
+   * use case may be to call $geometry->getComponents(array('Point', 'LineString', 'Polygon')) to break
+   * a collection down to the three basic geometry types.
+   *
+   * @param types an array of strings matching valid features types as listed in geoPHP::geometryTypes()
    * @return array
    */
-  public function getComponents() {
-    return $this->components;
+  public function getComponents($types = array()) {
+    // If no parameters are provided behave as always and return the components stored in this instance.
+    if (!$types) {
+      return $this->components;
+    }
+
+    // If a string is provided as a parameter place it into an array before continuing.
+    if (is_string($types)) {
+      $types = array($types);
+    }
+
+    // If the provided parameter is neither a string nor an array do nothing.
+    if (is_array($types)) {
+      // Make sure that the types array contains at least the Point geometry type.
+      if (!in_array('Point', $types)) {
+	$types[] = 'Point';
+      }
+      return $this->getComponentsRecursive($types);
+    }
+  }
+
+  private function getComponentsRecursive($types = array('Point')) {
+    // If the current geometry is of a type in the types array we can return it.
+    if (in_array($this->geometryType(), $types)) {
+      return array($this);
+    }
+
+    $components = array();
+    foreach ($this->components as $component) {
+      // Simply add geometries that match the given types to the return array to avoid calling
+      // nonexistent getComponentsRecursive method on Point geometries.
+      if (in_array($component->geometryType(), $types)) {
+	$components[] = $component;
+      } else {
+	$components = array_merge($components, $component->getComponentsRecursive($types));
+      }
+    }
+
+    return $components;
   }
 
   public function centroid() {