fix parsing of EMPTY wkt geometries

lib/adapters/WKT.class.php

@@ -4,7 +4,7 @@
  */
 class WKT extends GeoAdapter
 {
-  
+
   /**
    * Read WKT string into geometry objects
    *
@@ -14,7 +14,7 @@ class WKT extends GeoAdapter
    */
   public function read($wkt) {
     $wkt = trim($wkt);
-    
+
     // If it contains a ';', then it contains additional SRID data
     if (strpos($wkt,';')) {
       $parts = explode(';', $wkt);
@@ -25,7 +25,7 @@ public function read($wkt) {
     else {
       $srid = NULL;
     }
-    
+
     // If geos is installed, then we take a shortcut and let it parse the WKT
     if (geoPHP::geosInstalled()) {
       $reader = new GEOSWKTReader();
@@ -34,35 +34,39 @@ public function read($wkt) {
         $geom->setSRID($srid);
         return $geom;
       }
-      else { 
+      else {
         return geoPHP::geosToGeometry($reader->read($wkt));
       }
     }
     $wkt = str_replace(', ', ',', $wkt);
-    
+
     // For each geometry type, check to see if we have a match at the
-    // beggining of the string. If we do, then parse using that type
+    // beginning of the string. If we do, then parse using that type
     foreach (geoPHP::geometryList() as $geom_type) {
       $wkt_geom = strtoupper($geom_type);
       if (strtoupper(substr($wkt, 0, strlen($wkt_geom))) == $wkt_geom) {
         $data_string = $this->getDataString($wkt);
         $method = 'parse'.$geom_type;
-        
+
         if ($srid) {
           $geom = $this->$method($data_string);
           $geom->setSRID($srid);
           return $geom;
         }
-        else { 
+        else {
           return $this->$method($data_string);
         }
-        
+
       }
     }
   }
-  
+
   private function parsePoint($data_string) {
     $data_string = $this->trimParens($data_string);
+
+    // If it's marked as empty, then return an empty point
+    if ($data_string == 'EMPTY') return new Point();
+
     $parts = explode(' ',$data_string);
     return new Point($parts[0], $parts[1]);
   }
@@ -72,7 +76,7 @@ private function parseLineString($data_string) {
 
     // If it's marked as empty, then return an empty line
     if ($data_string == 'EMPTY') return new LineString();
-    
+
     $parts = explode(',',$data_string);
     $points = array();
     foreach ($parts as $part) {
@@ -83,10 +87,10 @@ private function parseLineString($data_string) {
 
   private function parsePolygon($data_string) {
     $data_string = $this->trimParens($data_string);
-    
+
     // If it's marked as empty, then return an empty polygon
     if ($data_string == 'EMPTY') return new Polygon();
-    
+
     $parts = explode('),(',$data_string);
     $lines = array();
     foreach ($parts as $part) {
@@ -99,24 +103,24 @@ private function parsePolygon($data_string) {
 
   private function parseMultiPoint($data_string) {
     $data_string = $this->trimParens($data_string);
-    
+
     // If it's marked as empty, then return an empty MutiPoint
     if ($data_string == 'EMPTY') return new MultiPoint();
-    
+
     $parts = explode(',',$data_string);
     $points = array();
     foreach ($parts as $part) {
       $points[] = $this->parsePoint($part);
     }
     return new MultiPoint($points);
   }
-  
+
   private function parseMultiLineString($data_string) {
     $data_string = $this->trimParens($data_string);
 
     // If it's marked as empty, then return an empty multi-linestring
     if ($data_string == 'EMPTY') return new MultiLineString();
-    
+
     $parts = explode('),(',$data_string);
     $lines = array();
     foreach ($parts as $part) {
@@ -133,7 +137,7 @@ private function parseMultiPolygon($data_string) {
 
     // If it's marked as empty, then return an empty multi-polygon
     if ($data_string == 'EMPTY') return new MultiPolygon();
-    
+
     $parts = explode(')),((',$data_string);
     $polys = array();
     foreach ($parts as $part) {
@@ -150,12 +154,12 @@ private function parseGeometryCollection($data_string) {
 
     // If it's marked as empty, then return an empty geom-collection
     if ($data_string == 'EMPTY') return new GeometryCollection();
-    
+
     $geometries = array();
     $matches = array();
     $str = preg_replace('/,\s*([A-Za-z])/', '|$1', $data_string);
     $components = explode('|', trim($str));
-    
+
     foreach ($components as $component) {
       $geometries[] = $this->read($component);
     }
@@ -167,23 +171,25 @@ protected function getDataString($wkt) {
 
     if ($first_paren !== FALSE) {
       return substr($wkt, $first_paren);
-    }
-    return FALSE;
+    } elseif (strstr($wkt,'EMPTY')) {
+      return 'EMPTY';
+    } else
+      return FALSE;
   }
-  
+
   /**
    * Trim the parenthesis and spaces
    */
   protected function trimParens($str) {
     $str = trim($str);
-    
+
     // We want to only strip off one set of parenthesis
     if ($this->beginsWith($str, '(')) {
       return substr($str,1,-1);
     }
     else return $str;
   }
-  
+
   protected function beginsWith($str, $char) {
     if (substr($str,0,strlen($char)) == $char) return TRUE;
     else return FALSE;
@@ -193,7 +199,7 @@ protected function endsWith($str, $char) {
     if (substr($str,(0 - strlen($char))) == $char) return TRUE;
     else return FALSE;
   }
-    
+
   /**
    * Serialize geometries into a WKT string.
    *
@@ -208,15 +214,15 @@ public function write(Geometry $geometry) {
       $writer->setTrim(TRUE);
       return $writer->write($geometry->geos());
     }
-    
+
     if ($geometry->isEmpty()) {
       return strtoupper($geometry->geometryType()).' EMPTY';
     }
     else if ($data = $this->extractData($geometry)) {
       return strtoupper($geometry->geometryType()).' ('.$data.')';
     }
   }
-  
+
   /**
    * Extract geometry to a WKT string
    *

tests/input/empty_point.wkt

@@ -0,0 +1 @@
+POINT EMPTY