validate:media-descriptor-parser: Add a way to create from a string

So it is simple to make use of it from the testsuite

https://bugzilla.gnome.org/show_bug.cgi?id=736138

validate/gst/validate/media-descriptor-parser.c

@@ -263,26 +263,42 @@ static const GMarkupParser content_parser = {
   &on_error_cb
 };
 
+static gboolean
+_set_content (GstMediaDescriptorParser * parser,
+    const gchar * content, gsize size, GError ** error)
+{
+  GError *err = NULL;
+  GstMediaDescriptorParserPrivate *priv = parser->priv;
+
+  priv->parsecontext = g_markup_parse_context_new (&content_parser,
+      G_MARKUP_TREAT_CDATA_AS_TEXT, parser, NULL);
+
+  if (g_markup_parse_context_parse (priv->parsecontext, content,
+          size, &err) == FALSE)
+    goto failed;
+
+  return TRUE;
+
+failed:
+  g_propagate_error (error, err);
+  return FALSE;
+}
+
 static gboolean
 set_xml_path (GstMediaDescriptorParser * parser, const gchar * path,
     GError ** error)
 {
   gsize xmlsize;
+  gchar *content;
   GError *err = NULL;
   GstMediaDescriptorParserPrivate *priv = parser->priv;
 
-  if (!g_file_get_contents (path, &priv->xmlcontent, &xmlsize, &err))
+  if (!g_file_get_contents (path, &content, &xmlsize, &err))
     goto failed;
 
   priv->xmlpath = g_strdup (path);
-  priv->parsecontext = g_markup_parse_context_new (&content_parser,
-      G_MARKUP_TREAT_CDATA_AS_TEXT, parser, NULL);
 
-  if (g_markup_parse_context_parse (priv->parsecontext, priv->xmlcontent,
+  return _set_content (parser, content, xmlsize, error);
-          xmlsize, &err) == FALSE)
-    goto failed;
-
-  return TRUE;
 
 failed:
   g_propagate_error (error, err);
@@ -381,6 +397,25 @@ gst_media_descriptor_parser_new (GstValidateRunner * runner,
   return parser;
 }
 
+GstMediaDescriptorParser *
+gst_media_descriptor_parser_new_from_xml (GstValidateRunner * runner,
+    const gchar * xml, GError ** error)
+{
+  GstMediaDescriptorParser *parser;
+
+  parser = g_object_new (GST_TYPE_MEDIA_DESCRIPTOR_PARSER, "validate-runner",
+      runner, NULL);
+  if (_set_content (parser, g_strdup (xml), strlen (xml) * sizeof (gchar),
+          error) == FALSE) {
+    g_object_unref (parser);
+
+    return NULL;
+  }
+
+
+  return parser;
+}
+
 gchar *
 gst_media_descriptor_parser_get_xml_path (GstMediaDescriptorParser * parser)
 {

validate/gst/validate/media-descriptor-parser.h

@@ -58,6 +58,10 @@ typedef struct {
 GstMediaDescriptorParser * gst_media_descriptor_parser_new (GstValidateRunner *runner,
                                                             const gchar * xmlpath,
                                                             GError **error);
+GstMediaDescriptorParser *
+gst_media_descriptor_parser_new_from_xml                   (GstValidateRunner * runner,
+                                                            const gchar * xml,
+                                                            GError ** error);
 gchar * gst_media_descriptor_parser_get_xml_path        (GstMediaDescriptorParser *parser);
 gboolean gst_media_descriptor_parser_add_stream         (GstMediaDescriptorParser *parser,
                                                                   GstPad *pad);