flush

[m6w6/pq-gateway] / lib / pq / Query / Expr.php

diff --git a/lib/pq/Query/Expr.php b/lib/pq/Query/Expr.php
index d02b13fea5d07781a9f136eb249fff5de8963796..ae87c1f92abe4b4bdd4d20f1cc6d5c2d9f9b6ce0 100644 (file)
--- a/lib/pq/Query/Expr.php
+++ b/lib/pq/Query/Expr.php
@@ -8,6 +8,11 @@ class Expr
         * @var string
         */
        protected $expression;
+       
+       /**
+        * @var \pq\Query\Expr
+        */
+       protected $next;
 
        /**
         * @param string $e the expression or a format string followed by arguments
@@ -15,10 +20,9 @@ class Expr
         */
        function __construct($e) {
                if (func_num_args() > 1) {
-                       $this->expression = call_user_func_array("sprintf", func_get_args());
-               } else {
-                       $this->expression = $e;
+                       $e = call_user_func_array("sprintf", func_get_args());
                }
+               $this->expression = trim($e);
        }
 
        /**
@@ -26,6 +30,29 @@ class Expr
         * @return string
         */
        function __toString() {
-               return (string) $this->expression;
+               return (string) $this->expression . $this->next;
+       }
+       
+       /**
+        * Check for NULL
+        * @return bool
+        */
+       function isNull() {
+               return !strcasecmp($this->expression, "null");
+       }
+       
+       /**
+        * Append an expresssion
+        * @param \pq\Query\Expr $next
+        * @return \pq\Query\Expr $this
+        * @throws \UnexpectedValueException if any expr is NULL
+        */
+       function add(Expr $next) {
+               if ($this->isNull() || $next->isNull()) {
+                       throw new \UnexpectedValueException("Cannot add anything to NULL");
+               }
+               for ($that = $this; $that->next; $that = $that->next);
+               $that->next = $next;
+               return $this;
        }
 }