form : add the javascript to focus on the first field if there is no error, or on the first error when there is one

git-svn-id: https://svn.fournier38.fr/svn/ProgSVN/trunk@2534 bf3deb0d-5f1a-0410-827f-c0cc1f45334c

form.php

@@ -212,6 +212,21 @@ class form
       $res .= $csrf->displayFormCSRF ();
     }
 
+    // Manage the focus. On the first visible element if there is no error, on
+    // the first error fields when there is one
+    foreach ($this->fields as $field)
+    {
+      if ($field->type !== "hidden")
+        break;
+    }
+    $focusElement = $field->name;
+    if (count ($errors) > 0)
+    {
+      reset ($errors);
+      $focusElement = key ($errors);
+    } 
+    $res .= "<script>document.getElementById('".$this->formName."_".
+            $focusElement."').focus();</script>\n";
     $res .= "</form>\n";
     return $res;
   }