Merge pull request joomla#75 from wilsonge/patch-1

Add note about Concatenation spacing

Author: mbabker

manual/en-US/coding-standards/chapters/php.md

@@ -145,6 +145,24 @@ $ref1 = &$this->sql;
 >
 > In PHP 5, reference operators are not required for objects. All objects are handled by reference.
 
+## Concatenation Spacing
+There should always be a space before and after the concatenation operator ('.'). For example:
+
+```php
+$id = 1;
+echo JRoute('index.php?option=com_foo&task=foo.edit&id=' . (int) $id);
+```
+
+If the concatenation operator is the first or last character on a line, both spaces are not required. For example:
+
+```php
+$id = 1
+echo JRoute::_(
+    'index.php?option=com_foo&task=foo.edit&id=' . (int) $id
+    . '&layout=special'
+);
+```
+
 ## Arrays
 
 Assignments (the `=>` operator) in arrays may be aligned with tabs. When splitting array definitions onto several lines, the last value may also have a trailing comma. This is valid PHP syntax and helps to keep code diffs minimal.