💡 Add Doxygen fix for @var member variable documentation.

Add an input filter to Doxygen to parse @var class member variable
documentation, so it is bit more compatible how anybody else interpretes
it.

util/Doxyfile

@@ -32,3 +32,6 @@ DOT_IMAGE_FORMAT = svg
 INTERACTIVE_SVG = YES
 CLASS_GRAPH = YES
 COLLABORATION_GRAPH = NO
+# fix @var (https://bugzilla.gnome.org/show_bug.cgi?id=626105)
+#INPUT_FILTER = "sed -e 's/@var\s/@see /'"
+INPUT_FILTER = "php util/Doxygen_phpvarfilter.php"

util/Doxygen_phpvarfilter.php

@@ -0,0 +1,18 @@
+<?php
+/**
+ * @file Doxygen_phpvarfilter.php
+ * @brief A Doxygen INPUT_FILTER to parse \@var member variable documentation.
+ *
+ * An input filter for Doxygen to parse \@var class member variable documentation,
+ * so it is a bit more compatible how anybody else interpretes it.
+ *
+ * @see http://stackoverflow.com/questions/4325224/doxygen-how-to-describe-class-member-variables-in-php/8472180#8472180
+ */
+
+$source = file_get_contents($argv[1]);
+
+$regexp = '#\@var\s+([^\s]+)([^/]+)/\s+(var|public|protected|private)\s+(\$[^\s;=]+)#';
+$replac = '${2} */ ${3} ${1} ${4}';
+$source = preg_replace($regexp, $replac, $source);
+
+echo $source;