+/**
+ * Adds content type headers; by default the encoding used is utf-8.
+ */
+function pl_content_headers($content_type, $encoding = 'utf-8')
+{
+ if (is_null($encoding)) {
+ header("Content-Type: $content_type");
+ } else {
+ header("Content-Type: $content_type; charset=$encoding");
+ }
+}
+
+/**
+ * Adds content type and caching headers for content generated by plat/al. The
+ * cache duration defaults to the global static_cache_duration. No encoding is
+ * applied by default.
+ */
+function pl_cached_content_headers($content_type, $encoding = null, $cache_duration = -1)
+{
+ global $globals;
+ $cache_duration = ($cache_duration < 0 ? $globals->static_cache_duration : $cache_duration);
+
+ header("Cache-Control: max-age=$cache_duration");
+ header("Expires: " . gmdate('D, d M Y H:i:s', time() + $cache_duration) . " GMT");
+ pl_content_headers($content_type, $encoding);
+}
+
+/**
+ * Same as above, but applying an expiration time suitable for cacheable dynamic
+ * content (eg. photos, logos, ...).
+ */
+function pl_cached_dynamic_content_headers($content_type, $encoding = null)
+{
+ global $globals;
+ pl_cached_content_headers($content_type, $encoding, $globals->dynamic_cache_duration);
+}
+