Add functions to parse from and to insert a GNode

This allows us to trivially serialize objects to XML and back.
NOTE: as this uses a DOM parser, it's certainly not quick. Use something manual
like expat or GMarkupParser to do this more efficiently and with less memory.

9 files changed, 813 insertions, 38 deletions

diff --git a/libappstream-glib/as-app.c b/libappstream-glib/as-app.c
index 111d9bc..01e4e4c 100644
--- a/libappstream-glib/as-app.c
+++ b/libappstream-glib/as-app.c
@@ -22,12 +22,14 @@
 #include "config.h"
 
 #include "as-app.h"
+#include "as-node.h"
+#include "as-tag.h"
 
 typedef struct _AsAppPrivate	AsAppPrivate;
 struct _AsAppPrivate
 {
-	AsAppIconKind	 icon_type;
-	AsAppIdKind	 kind;
+	AsAppIconKind	 icon_kind;
+	AsAppIdKind	 id_kind;
 	GHashTable	*comments;			/* of locale:string */
 	GHashTable	*descriptions;			/* of locale:string */
 	GHashTable	*languages;			/* of locale:string */
@@ -120,19 +122,19 @@ as_app_class_init (AsAppClass *klass)
  * as_app_id_kind_to_string:
  **/
 const gchar *
-as_app_id_kind_to_string (AsAppIdKind kind)
+as_app_id_kind_to_string (AsAppIdKind id_kind)
 {
-	if (kind == AS_APP_ID_KIND_DESKTOP)
+	if (id_kind == AS_APP_ID_KIND_DESKTOP)
 		return "desktop";
-	if (kind == AS_APP_ID_KIND_CODEC)
+	if (id_kind == AS_APP_ID_KIND_CODEC)
 		return "codec";
-	if (kind == AS_APP_ID_KIND_FONT)
+	if (id_kind == AS_APP_ID_KIND_FONT)
 		return "font";
-	if (kind == AS_APP_ID_KIND_INPUT_METHOD)
+	if (id_kind == AS_APP_ID_KIND_INPUT_METHOD)
 		return "inputmethod";
-	if (kind == AS_APP_ID_KIND_WEB_APP)
+	if (id_kind == AS_APP_ID_KIND_WEB_APP)
 		return "webapp";
-	if (kind == AS_APP_ID_KIND_SOURCE)
+	if (id_kind == AS_APP_ID_KIND_SOURCE)
 		return "source";
 	return "unknown";
 }
@@ -141,35 +143,34 @@ as_app_id_kind_to_string (AsAppIdKind kind)
  * as_app_id_kind_from_string:
  **/
 AsAppIdKind
-as_app_id_kind_from_string (const gchar *kind)
+as_app_id_kind_from_string (const gchar *id_kind)
 {
-	if (g_strcmp0 (kind, "desktop") == 0)
+	if (g_strcmp0 (id_kind, "desktop") == 0)
 		return AS_APP_ID_KIND_DESKTOP;
-	if (g_strcmp0 (kind, "codec") == 0)
+	if (g_strcmp0 (id_kind, "codec") == 0)
 		return AS_APP_ID_KIND_CODEC;
-	if (g_strcmp0 (kind, "font") == 0)
+	if (g_strcmp0 (id_kind, "font") == 0)
 		return AS_APP_ID_KIND_FONT;
-	if (g_strcmp0 (kind, "inputmethod") == 0)
+	if (g_strcmp0 (id_kind, "inputmethod") == 0)
 		return AS_APP_ID_KIND_INPUT_METHOD;
-	if (g_strcmp0 (kind, "webapp") == 0)
+	if (g_strcmp0 (id_kind, "webapp") == 0)
 		return AS_APP_ID_KIND_WEB_APP;
-	if (g_strcmp0 (kind, "source") == 0)
+	if (g_strcmp0 (id_kind, "source") == 0)
 		return AS_APP_ID_KIND_SOURCE;
 	return AS_APP_ID_KIND_UNKNOWN;
 }
 
-
 /**
  * as_app_icon_kind_to_string:
  **/
 const gchar *
-as_app_icon_kind_to_string (AsAppIconKind icon_type)
+as_app_icon_kind_to_string (AsAppIconKind icon_kind)
 {
-	if (icon_type == AS_APP_ICON_KIND_CACHED)
+	if (icon_kind == AS_APP_ICON_KIND_CACHED)
 		return "cached";
-	if (icon_type == AS_APP_ICON_KIND_STOCK)
+	if (icon_kind == AS_APP_ICON_KIND_STOCK)
 		return "stock";
-	if (icon_type == AS_APP_ICON_KIND_REMOTE)
+	if (icon_kind == AS_APP_ICON_KIND_REMOTE)
 		return "remote";
 	return "unknown";
 }
@@ -178,13 +179,13 @@ as_app_icon_kind_to_string (AsAppIconKind icon_type)
  * as_app_icon_kind_from_string:
  **/
 AsAppIconKind
-as_app_icon_kind_from_string (const gchar *icon_type)
+as_app_icon_kind_from_string (const gchar *icon_kind)
 {
-	if (g_strcmp0 (icon_type, "cached") == 0)
+	if (g_strcmp0 (icon_kind, "cached") == 0)
 		return AS_APP_ICON_KIND_CACHED;
-	if (g_strcmp0 (icon_type, "stock") == 0)
+	if (g_strcmp0 (icon_kind, "stock") == 0)
 		return AS_APP_ICON_KIND_STOCK;
-	if (g_strcmp0 (icon_type, "remote") == 0)
+	if (g_strcmp0 (icon_kind, "remote") == 0)
 		return AS_APP_ICON_KIND_REMOTE;
 	return AS_APP_ICON_KIND_UNKNOWN;
 }
@@ -279,7 +280,17 @@ AsAppIdKind
 as_app_get_id_kind (AsApp *app)
 {
 	AsAppPrivate *priv = GET_PRIVATE (app);
-	return priv->kind;
+	return priv->id_kind;
+}
+
+/**
+ * as_app_get_icon_kind:
+ **/
+AsAppIconKind
+as_app_get_icon_kind (AsApp *app)
+{
+	AsAppPrivate *priv = GET_PRIVATE (app);
+	return priv->icon_kind;
 }
 
 /**
@@ -299,6 +310,8 @@ const gchar *
 as_app_get_name (AsApp *app, const gchar *locale)
 {
 	AsAppPrivate *priv = GET_PRIVATE (app);
+	if (locale == NULL)
+		locale = "C";
 	return g_hash_table_lookup (priv->names, locale);
 }
 
@@ -309,6 +322,8 @@ const gchar *
 as_app_get_comment (AsApp *app, const gchar *locale)
 {
 	AsAppPrivate *priv = GET_PRIVATE (app);
+	if (locale == NULL)
+		locale = "C";
 	return g_hash_table_lookup (priv->comments, locale);
 }
 
@@ -319,6 +334,8 @@ const gchar *
 as_app_get_language (AsApp *app, const gchar *locale)
 {
 	AsAppPrivate *priv = GET_PRIVATE (app);
+	if (locale == NULL)
+		locale = "C";
 	return g_hash_table_lookup (priv->languages, locale);
 }
 
@@ -362,6 +379,16 @@ as_app_get_project_group (AsApp *app)
 	return priv->project_group;
 }
 
+/**
+ * as_app_get_project_license:
+ **/
+const gchar *
+as_app_get_project_license (AsApp *app)
+{
+	AsAppPrivate *priv = GET_PRIVATE (app);
+	return priv->project_license;
+}
+
 /******************************************************************************/
 
 /**
@@ -385,10 +412,10 @@ as_app_set_id_full (AsApp *app, const gchar *id_full)
  * as_app_set_id_kind:
  **/
 void
-as_app_set_id_kind (AsApp *app, AsAppIdKind kind)
+as_app_set_id_kind (AsApp *app, AsAppIdKind id_kind)
 {
 	AsAppPrivate *priv = GET_PRIVATE (app);
-	priv->kind = kind;
+	priv->id_kind = id_kind;
 }
 
 /**
@@ -428,10 +455,10 @@ as_app_set_icon (AsApp *app, const gchar *icon)
  * as_app_set_icon_kind:
  **/
 void
-as_app_set_icon_kind (AsApp *app, AsAppIconKind icon_type)
+as_app_set_icon_kind (AsApp *app, AsAppIconKind icon_kind)
 {
 	AsAppPrivate *priv = GET_PRIVATE (app);
-	priv->icon_type = icon_type;
+	priv->icon_kind = icon_kind;
 }
 
 /**
@@ -610,6 +637,9 @@ void
 as_app_add_metadata (AsApp *app, const gchar *key, const gchar *value)
 {
 	AsAppPrivate *priv = GET_PRIVATE (app);
+	g_return_if_fail (key != NULL);
+	if (value == NULL)
+		value = "";
 	g_hash_table_insert (priv->metadata, g_strdup (key), g_strdup (value));
 }
 
@@ -668,6 +698,326 @@ as_app_subsume (AsApp *app, AsApp *donor)
 }
 
 /**
+ * as_app_node_insert:
+ **/
+GNode *
+as_app_node_insert (AsApp *app, GNode *parent)
+{
+	AsAppPrivate *priv = GET_PRIVATE (app);
+	AsRelease *rel;
+	AsScreenshot *ss;
+	GNode *node_app;
+	GNode *node_tmp;
+	const gchar *tmp;
+	guint i;
+
+	node_app = as_node_insert (parent, "application", NULL, 0, NULL);
+
+	/* <id> */
+	as_node_insert (node_app, "id", priv->id_full, 0,
+			"type", as_app_id_kind_to_string (priv->id_kind),
+			NULL);
+
+	/* <pkgname> */
+	for (i = 0; i < priv->pkgnames->len; i++) {
+		tmp = g_ptr_array_index (priv->pkgnames, i);
+		as_node_insert (node_app, "pkgname", tmp, 0, NULL);
+	}
+
+	/* <name> */
+	as_node_insert_localized (node_app, "name", priv->names, 0);
+
+	/* <summary> */
+	as_node_insert_localized (node_app, "summary", priv->comments, 0);
+
+	/* <description> */
+	as_node_insert_localized (node_app, "description", priv->descriptions,
+				  AS_NODE_INSERT_FLAG_PRE_ESCAPED);
+
+	/* <icon> */
+	if (priv->icon != NULL) {
+		as_node_insert (node_app, "icon", priv->icon, 0,
+				"type", as_app_icon_kind_to_string (priv->icon_kind),
+				NULL);
+	}
+
+	/* <categories> */
+	if (priv->categories->len > 0) {
+		node_tmp = as_node_insert (node_app, "appcategories", NULL, 0, NULL);
+		for (i = 0; i < priv->categories->len; i++) {
+			tmp = g_ptr_array_index (priv->categories, i);
+			as_node_insert (node_tmp, "appcategory", tmp, 0, NULL);
+		}
+	}
+
+	/* <keywords> */
+	if (priv->keywords->len > 0) {
+		node_tmp = as_node_insert (node_app, "keywords", NULL, 0, NULL);
+		for (i = 0; i < priv->keywords->len; i++) {
+			tmp = g_ptr_array_index (priv->keywords, i);
+			as_node_insert (node_tmp, "keyword", tmp, 0, NULL);
+		}
+	}
+
+	/* <mimetypes> */
+	if (priv->mimetypes->len > 0) {
+		node_tmp = as_node_insert (node_app, "mimetypes", NULL, 0, NULL);
+		for (i = 0; i < priv->mimetypes->len; i++) {
+			tmp = g_ptr_array_index (priv->mimetypes, i);
+			as_node_insert (node_tmp, "mimetype", tmp, 0, NULL);
+		}
+	}
+
+	/* <project_license> */
+	if (priv->project_license != NULL) {
+		as_node_insert (node_app, "project_license",
+				priv->project_license, 0, NULL);
+	}
+
+	/* <url> */
+//		as_node_insert (node_app, "url", priv->homepage_url, 0,
+//				"type", "homepage",
+//				NULL);
+	as_node_insert_hash (node_app, "url", "type", priv->urls, 0);
+
+	/* <project_group> */
+	if (priv->project_group != NULL) {
+		as_node_insert (node_app, "project_group",
+				priv->project_group, 0, NULL);
+	}
+
+	/* <compulsory_for_desktop> */
+	if (priv->compulsory_for_desktop != NULL) {
+		for (i = 0; i < priv->compulsory_for_desktop->len; i++) {
+			tmp = g_ptr_array_index (priv->compulsory_for_desktop, i);
+			as_node_insert (node_app, "compulsory_for_desktop",
+					tmp, 0, NULL);
+		}
+	}
+
+	/* <screenshots> */
+	if (priv->screenshots->len > 0) {
+		node_tmp = as_node_insert (node_app, "screenshots", NULL, 0, NULL);
+		for (i = 0; i < priv->screenshots->len; i++) {
+			ss = g_ptr_array_index (priv->screenshots, i);
+			as_screenshot_node_insert (ss, node_tmp);
+		}
+	}
+
+	/* <releases> */
+	if (priv->releases->len > 0) {
+		node_tmp = as_node_insert (node_app, "releases", NULL, 0, NULL);
+		for (i = 0; i < priv->releases->len && i < 3; i++) {
+			rel = g_ptr_array_index (priv->releases, i);
+			as_release_node_insert (rel, node_tmp);
+		}
+	}
+
+	/* <languages> */
+	if (g_hash_table_size (priv->languages) > 0) {
+		node_tmp = as_node_insert (node_app, "languages", NULL, 0, NULL);
+		as_node_insert_hash (node_tmp, "lang", "percentage", priv->languages, TRUE);
+	}
+
+	/* <metadata> */
+	if (g_hash_table_size (priv->metadata) > 0) {
+		node_tmp = as_node_insert (node_app, "metadata", NULL, 0, NULL);
+		as_node_insert_hash (node_tmp, "value", "key", priv->metadata, FALSE);
+	}
+
+	return node_app;
+}
+
+/**
+ * as_app_node_parse_child:
+ **/
+static gboolean
+as_app_node_parse_child (AsApp *app, GNode *n, GError **error)
+{
+	AsTag tag;
+	GNode *c;
+	GString *xml;
+	const gchar *tmp;
+	gboolean ret = TRUE;
+
+	/* <id> */
+	tag = as_tag_from_string (as_node_get_name (n));
+	if (tag == AS_TAG_ID) {
+		tmp = as_node_get_attribute (n, "type");
+		as_app_set_id_kind (app, as_app_id_kind_from_string (tmp));
+		as_app_set_id_full (app, as_node_get_data (n));
+		goto out;
+	}
+
+	/* <pkgname> */
+	if (tag == AS_TAG_PKGNAME) {
+		as_app_add_pkgname (app, as_node_get_data (n));
+		goto out;
+	}
+
+	/* <name> */
+	if (tag == AS_TAG_NAME) {
+		as_app_set_name (app,
+				 as_node_get_attribute (n, "xml:lang"),
+				 as_node_get_data (n));
+	}
+
+	/* <summary> */
+	if (tag == AS_TAG_SUMMARY) {
+		as_app_set_comment (app,
+				    as_node_get_attribute (n, "xml:lang"),
+				    as_node_get_data (n));
+	}
+
+	/* <description> */
+	if (tag == AS_TAG_DESCRIPTION) {
+		xml = as_node_to_xml (n->children, AS_NODE_TO_XML_FLAG_NONE);
+		as_app_set_description (app,
+					 as_node_get_attribute (n, "xml:lang"),
+					 xml->str);
+		g_string_free (xml, TRUE);
+	}
+
+	/* <icon> */
+	if (tag == AS_TAG_ICON) {
+		tmp = as_node_get_attribute (n, "type");
+		as_app_set_icon_kind (app, as_app_icon_kind_from_string (tmp));
+		as_app_set_icon (app, as_node_get_data (n));
+		goto out;
+	}
+
+	/* <categories> */
+	if (tag == AS_TAG_APPCATEGORIES) {
+		for (c = n->children; c != NULL; c = c->next) {
+			if (g_strcmp0 (as_node_get_name (c),
+				       "appcategory") != 0)
+				continue;
+			as_app_add_category (app, as_node_get_data (c));
+		}
+	}
+
+	/* <keywords> */
+	if (tag == AS_TAG_KEYWORDS) {
+		for (c = n->children; c != NULL; c = c->next) {
+			if (g_strcmp0 (as_node_get_name (c),
+				       "keyword") != 0)
+				continue;
+			as_app_add_keyword (app, as_node_get_data (c));
+		}
+	}
+
+	/* <mimetypes> */
+	if (tag == AS_TAG_MIMETYPES) {
+		for (c = n->children; c != NULL; c = c->next) {
+			if (g_strcmp0 (as_node_get_name (c),
+				       "mimetype") != 0)
+				continue;
+			as_app_add_mimetype (app, as_node_get_data (c));
+		}
+	}
+
+	/* <project_license> */
+	if (tag == AS_TAG_PROJECT_LICENSE) {
+		as_app_set_project_license (app, as_node_get_data (n));
+		goto out;
+	}
+
+	/* <url> */
+	if (tag == AS_TAG_URL) {
+		tmp = as_node_get_attribute (n, "type");
+		as_app_add_url (app, tmp, as_node_get_data (n));
+		goto out;
+	}
+
+	/* <project_group> */
+	if (tag == AS_TAG_PROJECT_GROUP) {
+		as_app_set_project_group (app, as_node_get_data (n));
+		goto out;
+	}
+
+	/* <compulsory_for_desktop> */
+	if (tag == AS_TAG_COMPULSORY_FOR_DESKTOP) {
+		as_app_add_compulsory_for_desktop (app, as_node_get_data (n));
+		goto out;
+	}
+
+	/* <screenshots> */
+	if (tag == AS_TAG_SCREENSHOTS) {
+		AsScreenshot *ss;
+		for (c = n->children; c != NULL; c = c->next) {
+			if (g_strcmp0 (as_node_get_name (c), "screenshot") != 0)
+				continue;
+			ss = as_screenshot_new ();
+			ret = as_screenshot_node_parse (ss, c, error);
+			if (!ret) {
+				g_object_unref (ss);
+				goto out;
+			}
+			as_app_add_screenshot (app, ss);
+			g_object_unref (ss);
+		}
+	}
+
+	/* <releases> */
+	if (tag == AS_TAG_RELEASES) {
+		AsRelease *r;
+		for (c = n->children; c != NULL; c = c->next) {
+			if (g_strcmp0 (as_node_get_name (c), "release") != 0)
+				continue;
+			r = as_release_new ();
+			ret = as_release_node_parse (r, c, error);
+			if (!ret) {
+				g_object_unref (r);
+				goto out;
+			}
+			as_app_add_release (app, r);
+			g_object_unref (r);
+		}
+	}
+
+	/* <languages> */
+	if (tag == AS_TAG_LANGUAGES) {
+		for (c = n->children; c != NULL; c = c->next) {
+			if (g_strcmp0 (as_node_get_name (c), "lang") != 0)
+				continue;
+			tmp = as_node_get_attribute (c, "percentage");
+			as_app_add_language (app, as_node_get_data (c), tmp);
+		}
+	}
+
+	/* <metadata> */
+	if (tag == AS_TAG_METADATA) {
+		for (c = n->children; c != NULL; c = c->next) {
+			if (g_strcmp0 (as_node_get_name (c), "value") != 0)
+				continue;
+			tmp = as_node_get_attribute (c, "key");
+			as_app_add_metadata (app, tmp, as_node_get_data (c));
+		}
+	}
+out:
+	return ret;
+}
+
+/**
+ * as_app_node_parse:
+ **/
+gboolean
+as_app_node_parse (AsApp *app, GNode *node, GError **error)
+{
+	GNode *n;
+	gboolean ret = TRUE;
+
+	/* parse each node */
+	for (n = node->children; n != NULL; n = n->next) {
+		ret = as_app_node_parse_child (app, n, error);
+		if (!ret)
+			goto out;
+	}
+out:
+	return ret;
+}
+
+/**
  * as_app_new:
  **/
 AsApp *
diff --git a/libappstream-glib/as-app.h b/libappstream-glib/as-app.h
index b734821..f5bcfc1 100644
--- a/libappstream-glib/as-app.h
+++ b/libappstream-glib/as-app.h
@@ -76,12 +76,13 @@ GType		 as_app_get_type		(void);
 AsApp		*as_app_new			(void);
 
 /* helpers */
-const gchar	*as_app_id_kind_to_string	(AsAppIdKind	 kind);
-AsAppIdKind	 as_app_id_kind_from_string	(const gchar	*kind);
-const gchar	*as_app_icon_kind_to_string	(AsAppIconKind	 icon_type);
-AsAppIconKind	 as_app_icon_kind_from_string	(const gchar	*icon_type);
+const gchar	*as_app_id_kind_to_string	(AsAppIdKind	 id_kind);
+AsAppIdKind	 as_app_id_kind_from_string	(const gchar	*id_kind);
+const gchar	*as_app_icon_kind_to_string	(AsAppIconKind	 icon_kind);
+AsAppIconKind	 as_app_icon_kind_from_string	(const gchar	*icon_kind);
 
 /* getters */
+AsAppIconKind	 as_app_get_icon_kind		(AsApp		*app);
 AsAppIdKind	 as_app_get_id_kind		(AsApp		*app);
 GList		*as_app_get_languages		(AsApp		*app);
 GPtrArray	*as_app_get_categories		(AsApp		*app);
@@ -94,6 +95,7 @@ const gchar	*as_app_get_icon		(AsApp		*app);
 const gchar	*as_app_get_id			(AsApp		*app);
 const gchar	*as_app_get_id_full		(AsApp		*app);
 const gchar	*as_app_get_project_group	(AsApp		*app);
+const gchar	*as_app_get_project_license	(AsApp		*app);
 const gchar	*as_app_get_name		(AsApp		*app,
 						 const gchar	*locale);
 const gchar	*as_app_get_comment		(AsApp		*app,
@@ -109,7 +111,7 @@ const gchar	*as_app_get_url_item		(AsApp		*app,
 void		 as_app_set_id_full		(AsApp		*app,
 						 const gchar	*id_full);
 void		 as_app_set_id_kind		(AsApp		*app,
-						 AsAppIdKind	 kind);
+						 AsAppIdKind	 id_kind);
 void		 as_app_set_project_group	(AsApp		*app,
 						 const gchar	*project_group);
 void		 as_app_set_project_license	(AsApp		*app,
@@ -117,7 +119,7 @@ void		 as_app_set_project_license	(AsApp		*app,
 void		 as_app_set_icon		(AsApp		*app,
 						 const gchar	*icon);
 void		 as_app_set_icon_kind		(AsApp		*app,
-						 AsAppIconKind	 icon_type);
+						 AsAppIconKind	 icon_kind);
 void		 as_app_set_name		(AsApp		*app,
 						 const gchar	*locale,
 						 const gchar	*name);
@@ -154,6 +156,11 @@ void		 as_app_remove_metadata		(AsApp		*app,
 						 const gchar	*key);
 
 /* object methods */
+GNode		*as_app_node_insert		(AsApp		*app,
+						 GNode		*parent);
+gboolean	 as_app_node_parse		(AsApp		*app,
+						 GNode		*node,
+						 GError		**error);
 void		 as_app_subsume			(AsApp		*app,
 						 AsApp		*donor);
 
diff --git a/libappstream-glib/as-image.c b/libappstream-glib/as-image.c
index 177a332..8b17294 100644
--- a/libappstream-glib/as-image.c
+++ b/libappstream-glib/as-image.c
@@ -21,7 +21,11 @@
 
 #include "config.h"
 
+#include <stdlib.h>
+#include <string.h>
+
 #include "as-image.h"
+#include "as-node.h"
 
 typedef struct _AsImagePrivate	AsImagePrivate;
 struct _AsImagePrivate
@@ -143,6 +147,8 @@ as_image_set_url (AsImage *image, const gchar *url, gsize url_len)
 {
 	AsImagePrivate *priv = GET_PRIVATE (image);
 	g_free (priv->url);
+	if (url_len == (gsize) -1)
+		url_len = strlen (url);
 	priv->url = g_strndup (url, url_len);
 }
 
@@ -177,6 +183,57 @@ as_image_set_kind (AsImage *image, AsImageKind kind)
 }
 
 /**
+ * as_image_node_insert:
+ **/
+GNode *
+as_image_node_insert (AsImage *image, GNode *parent)
+{
+	AsImagePrivate *priv = GET_PRIVATE (image);
+	GNode *n;
+	gchar tmp_height[6];
+	gchar tmp_width[6];
+
+	if (priv->width > 0 && priv->height > 0) {
+		g_snprintf (tmp_width, sizeof (tmp_width), "%u", priv->width);
+		g_snprintf (tmp_height, sizeof (tmp_height), "%u", priv->height);
+		n = as_node_insert (parent, "image", priv->url,
+				    AS_NODE_INSERT_FLAG_NONE,
+				    "width", tmp_width,
+				    "height", tmp_height,
+				    "type", as_image_kind_to_string (priv->kind),
+				    NULL);
+	} else {
+		n = as_node_insert (parent, "image", priv->url,
+				    AS_NODE_INSERT_FLAG_NONE,
+				    "type", as_image_kind_to_string (priv->kind),
+				    NULL);
+	}
+	return n;
+}
+
+/**
+ * as_image_node_parse:
+ **/
+gboolean
+as_image_node_parse (AsImage *image, GNode *node, GError **error)
+{
+	const gchar *tmp;
+	tmp = as_node_get_attribute (node, "width");
+	if (tmp != NULL)
+		as_image_set_width (image, atoi (tmp));
+	tmp = as_node_get_attribute (node, "height");
+	if (tmp != NULL)
+		as_image_set_height (image, atoi (tmp));
+	tmp = as_node_get_attribute (node, "type");
+	if (tmp != NULL)
+		as_image_set_kind (image, as_image_kind_from_string (tmp));
+	tmp = as_node_get_data (node);
+	if (tmp != NULL)
+		as_image_set_url (image, tmp, -1);
+	return TRUE;
+}
+
+/**
  * as_image_new:
  **/
 AsImage *
diff --git a/libappstream-glib/as-image.h b/libappstream-glib/as-image.h
index 0c1f870..2e90c73 100644
--- a/libappstream-glib/as-image.h
+++ b/libappstream-glib/as-image.h
@@ -60,14 +60,17 @@ typedef enum {
 GType		 as_image_get_type		(void);
 AsImage		*as_image_new			(void);
 
+/* helpers */
 AsImageKind	 as_image_kind_from_string	(const gchar	*kind);
 const gchar	*as_image_kind_to_string	(AsImageKind	 kind);
 
+/* getters */
 const gchar	*as_image_get_url		(AsImage	*image);
 guint		 as_image_get_width		(AsImage	*image);
 guint		 as_image_get_height		(AsImage	*image);
 AsImageKind	 as_image_get_kind		(AsImage	*image);
 
+/* setters */
 void		 as_image_set_url		(AsImage	*image,
 						 const gchar	*url,
 						 gsize		 url_len);
@@ -78,6 +81,13 @@ void		 as_image_set_height		(AsImage	*image,
 void		 as_image_set_kind		(AsImage	*image,
 						 AsImageKind	 kind);
 
+/* object methods */
+GNode		*as_image_node_insert		(AsImage	*image,
+						 GNode		*parent);
+gboolean	 as_image_node_parse		(AsImage	*image,
+						 GNode		*node,
+						 GError		**error);
+
 G_END_DECLS
 
 #endif /* AS_IMAGE_H */
diff --git a/libappstream-glib/as-release.c b/libappstream-glib/as-release.c
index 9d1fe17..b4ab2a2 100644
--- a/libappstream-glib/as-release.c
+++ b/libappstream-glib/as-release.c
@@ -21,6 +21,9 @@
 
 #include "config.h"
 
+#include <stdlib.h>
+
+#include "as-node.h"
 #include "as-release.h"
 
 typedef struct _AsReleasePrivate	AsReleasePrivate;
@@ -129,6 +132,46 @@ as_release_set_description (AsRelease *release, const gchar *description)
 }
 
 /**
+ * as_release_node_insert:
+ **/
+GNode *
+as_release_node_insert (AsRelease *release, GNode *parent)
+{
+	AsReleasePrivate *priv = GET_PRIVATE (release);
+	GNode *n;
+	gchar *timestamp_str;
+
+	timestamp_str = g_strdup_printf ("%" G_GUINT64_FORMAT,
+					 priv->timestamp);
+	n = as_node_insert (parent, "release", priv->description,
+			    AS_NODE_INSERT_FLAG_NONE,
+			    "timestamp", timestamp_str,
+			    "version", priv->version,
+			    NULL);
+	g_free (timestamp_str);
+	return n;
+}
+
+/**
+ * as_release_node_parse:
+ **/
+gboolean
+as_release_node_parse (AsRelease *release, GNode *node, GError **error)
+{
+	const gchar *tmp;
+	tmp = as_node_get_attribute (node, "timestamp");
+	if (tmp != NULL)
+		as_release_set_timestamp (release, atol (tmp));
+	tmp = as_node_get_attribute (node, "version");
+	if (tmp != NULL)
+		as_release_set_version (release, tmp);
+	tmp = as_node_get_data (node);
+	if (tmp != NULL)
+		as_release_set_description (release, tmp);
+	return TRUE;
+}
+
+/**
  * as_release_new:
  **/
 AsRelease *
diff --git a/libappstream-glib/as-release.h b/libappstream-glib/as-release.h
index 9e09566..0c3b3f6 100644
--- a/libappstream-glib/as-release.h
+++ b/libappstream-glib/as-release.h
@@ -53,10 +53,12 @@ struct _AsReleaseClass
 GType		 as_release_get_type		(void);
 AsRelease	*as_release_new			(void);
 
+/* getters */
 const gchar	*as_release_get_version		(AsRelease	*release);
 guint64		 as_release_get_timestamp	(AsRelease	*release);
 const gchar	*as_release_get_description	(AsRelease	*release);
 
+/* setters */
 void		 as_release_set_version		(AsRelease	*release,
 						 const gchar	*version);
 void		 as_release_set_timestamp	(AsRelease	*release,
@@ -64,6 +66,13 @@ void		 as_release_set_timestamp	(AsRelease	*release,
 void		 as_release_set_description	(AsRelease	*release,
 						 const gchar	*description);
 
+/* object methods */
+GNode		*as_release_node_insert		(AsRelease	*release,
+						 GNode		*parent);
+gboolean	 as_release_node_parse		(AsRelease	*release,
+						 GNode		*node,
+						 GError		**error);
+
 G_END_DECLS
 
 #endif /* AS_RELEASE_H */
diff --git a/libappstream-glib/as-screenshot.c b/libappstream-glib/as-screenshot.c
index 1e0ff4b..ab213d9 100644
--- a/libappstream-glib/as-screenshot.c
+++ b/libappstream-glib/as-screenshot.c
@@ -21,7 +21,11 @@
 
 #include "config.h"
 
+#include <string.h>
+
+#include "as-node.h"
 #include "as-screenshot.h"
+#include "as-tag.h"
 
 typedef struct _AsScreenshotPrivate	AsScreenshotPrivate;
 struct _AsScreenshotPrivate
@@ -162,12 +166,90 @@ as_screenshot_set_caption (AsScreenshot *screenshot,
 	AsScreenshotPrivate *priv = GET_PRIVATE (screenshot);
 	if (locale == NULL)
 		locale = "C";
+	if (caption_length == (gsize) -1)
+		caption_length = strlen (caption);
 	g_hash_table_insert (priv->captions,
 			     g_strdup (locale),
 			     g_strndup (caption, caption_length));
 }
 
 /**
+ * as_screenshot_node_insert:
+ **/
+GNode *
+as_screenshot_node_insert (AsScreenshot *screenshot, GNode *parent)
+{
+	AsImage *image;
+	AsScreenshotPrivate *priv = GET_PRIVATE (screenshot);
+	GNode *n;
+	guint i;
+
+	n = as_node_insert (parent, "screenshot", NULL,
+			    AS_NODE_INSERT_FLAG_NONE,
+			    "type", as_screenshot_kind_to_string (priv->kind),
+			    NULL);
+	as_node_insert_localized (n, "caption", priv->captions, 0);
+	for (i = 0; i < priv->images->len; i++) {
+		image = g_ptr_array_index (priv->images, i);
+		as_image_node_insert (image, n);
+	}
+	return n;
+}
+
+/**
+ * as_screenshot_node_parse:
+ **/
+gboolean
+as_screenshot_node_parse (AsScreenshot *screenshot, GNode *node, GError **error)
+{
+	AsImage *image;
+	AsScreenshotPrivate *priv = GET_PRIVATE (screenshot);
+	GHashTable *captions = NULL;
+	GList *keys;
+	GList *l;
+	GNode *c;
+	const gchar *tmp;
+	gboolean ret = TRUE;
+
+	tmp = as_node_get_attribute (node, "type");
+	if (tmp != NULL) {
+		as_screenshot_set_kind (screenshot,
+					as_screenshot_kind_from_string (tmp));
+	}
+
+	/* add captions */
+	captions = as_node_get_localized (node, "caption");
+	if (captions != NULL) {
+		keys = g_hash_table_get_keys (captions);
+		for (l = keys; l != NULL; l = l->next) {
+			tmp = l->data;
+			as_screenshot_set_caption (screenshot,
+						   tmp,
+						   g_hash_table_lookup (captions, tmp),
+						   -1);
+		}
+		g_list_free (keys);
+	}
+
+	/* add images */
+	for (c = node->children; c != NULL; c = c->next) {
+		if (as_tag_from_string (as_node_get_name (c)) != AS_TAG_IMAGE)
+			continue;
+		image = as_image_new ();
+		ret = as_image_node_parse (image, c, error);
+		if (!ret) {
+			g_object_unref (image);
+			goto out;
+		}
+		g_ptr_array_add (priv->images, image);
+	}
+out:
+	if (captions != NULL)
+		g_hash_table_unref (captions);
+	return ret;
+}
+
+/**
  * as_screenshot_new:
  **/
 AsScreenshot *
diff --git a/libappstream-glib/as-screenshot.h b/libappstream-glib/as-screenshot.h
index ba603dc..c820d01 100644
--- a/libappstream-glib/as-screenshot.h
+++ b/libappstream-glib/as-screenshot.h
@@ -62,23 +62,33 @@ typedef enum {
 GType		 as_screenshot_get_type		(void);
 AsScreenshot	*as_screenshot_new		(void);
 
+/* helpers */
 AsScreenshotKind as_screenshot_kind_from_string (const gchar	*kind);
 const gchar	*as_screenshot_kind_to_string	(AsScreenshotKind kind);
 
+/* getters */
 AsScreenshotKind as_screenshot_get_kind		(AsScreenshot	*screenshot);
-const gchar	*as_screenshot_get_caption	(AsScreenshot	*app,
+const gchar	*as_screenshot_get_caption	(AsScreenshot	*screenshot,
 						 const gchar	*locale);
 GPtrArray	*as_screenshot_get_images	(AsScreenshot	*screenshot);
 
+/* setters */
 void		 as_screenshot_set_kind		(AsScreenshot	*screenshot,
 						 AsScreenshotKind kind);
-void		 as_screenshot_set_caption	(AsScreenshot	*app,
+void		 as_screenshot_set_caption	(AsScreenshot	*screenshot,
 						 const gchar	*locale,
 						 const gchar	*caption,
 						 gsize		 caption_length);
 void		 as_screenshot_add_image	(AsScreenshot	*screenshot,
 						 AsImage	*image);
 
+/* object methods */
+GNode		*as_screenshot_node_insert	(AsScreenshot	*screenshot,
+						 GNode		*parent);
+gboolean	 as_screenshot_node_parse	(AsScreenshot	*screenshot,
+						 GNode		*node,
+						 GError		**error);
+
 G_END_DECLS
 
 #endif /* AS_SCREENSHOT_H */
diff --git a/libappstream-glib/as-self-test.c b/libappstream-glib/as-self-test.c
index d8947f1..623c67f 100644
--- a/libappstream-glib/as-self-test.c
+++ b/libappstream-glib/as-self-test.c
@@ -24,13 +24,217 @@
 #include <glib.h>
 
 #include "as-app.h"
+#include "as-image.h"
 #include "as-node.h"
+#include "as-release.h"
+#include "as-screenshot.h"
+
+static void
+ch_test_release_func (void)
+{
+	AsRelease *release;
+	GError *error = NULL;
+	GNode *n;
+	GNode *root;
+	GString *xml;
+	const gchar *src = "<release version=\"0.1.2\" timestamp=\"123\"/>";
+	gboolean ret;
+
+	release = as_release_new ();
+
+	/* to object */
+	root = as_node_from_xml (src, -1, &error);
+	g_assert_no_error (error);
+	g_assert (root != NULL);
+	n = as_node_find (root, "release");
+	g_assert (n != NULL);
+	ret = as_release_node_parse (release, n, &error);
+	g_assert_no_error (error);
+	g_assert (ret);
+	as_node_unref (root);
+
+	/* verify */
+	g_assert_cmpint (as_release_get_timestamp (release), ==, 123);
+	g_assert_cmpstr (as_release_get_version (release), ==, "0.1.2");
+
+	/* back to node */
+	root = as_node_new ();
+	n = as_release_node_insert (release, root);
+	xml = as_node_to_xml (n, AS_NODE_TO_XML_FLAG_NONE);
+	g_assert_cmpstr (xml->str, ==, src);
+	g_string_free (xml, TRUE);
+	as_node_unref (root);
+
+	g_object_unref (release);
+}
+
+static void
+ch_test_image_func (void)
+{
+	AsImage *image;
+	GError *error = NULL;
+	GNode *n;
+	GNode *root;
+	GString *xml;
+	const gchar *src =
+		"<image type=\"thumbnail\" height=\"12\" width=\"34\">"
+		"http://www.hughsie.com/a.jpg</image>";
+	gboolean ret;
+
+	image = as_image_new ();
+
+	/* to object */
+	root = as_node_from_xml (src, -1, &error);
+	g_assert_no_error (error);
+	g_assert (root != NULL);
+	n = as_node_find (root, "image");
+	g_assert (n != NULL);
+	ret = as_image_node_parse (image, n, &error);
+	g_assert_no_error (error);
+	g_assert (ret);
+	as_node_unref (root);
+
+	/* verify */
+	g_assert_cmpint (as_image_get_kind (image), ==, AS_IMAGE_KIND_THUMBNAIL);
+	g_assert_cmpint (as_image_get_height (image), ==, 12);
+	g_assert_cmpint (as_image_get_width (image), ==, 34);
+	g_assert_cmpstr (as_image_get_url (image), ==, "http://www.hughsie.com/a.jpg");
+
+	/* back to node */
+	root = as_node_new ();
+	n = as_image_node_insert (image, root);
+	xml = as_node_to_xml (n, AS_NODE_TO_XML_FLAG_NONE);
+	g_assert_cmpstr (xml->str, ==, src);
+	g_string_free (xml, TRUE);
+	as_node_unref (root);
+
+	g_object_unref (image);
+}
+
+static void
+ch_test_screenshot_func (void)
+{
+	GPtrArray *images;
+	AsScreenshot *screenshot;
+	GError *error = NULL;
+	GNode *n;
+	GNode *root;
+	GString *xml;
+	const gchar *src =
+		"<screenshot type=\"normal\">"
+		"<caption>Hello</caption>"
+		"<image type=\"source\">http://1.png</image>"
+		"<image type=\"thumbnail\">http://2.png</image>"
+		"</screenshot>";
+	gboolean ret;
+
+	screenshot = as_screenshot_new ();
+
+	/* to object */
+	root = as_node_from_xml (src, -1, &error);
+	g_assert_no_error (error);
+	g_assert (root != NULL);
+	n = as_node_find (root, "screenshot");
+	g_assert (n != NULL);
+	ret = as_screenshot_node_parse (screenshot, n, &error);
+	g_assert_no_error (error);
+	g_assert (ret);
+
+	/* verify */
+	g_assert_cmpint (as_screenshot_get_kind (screenshot), ==, AS_SCREENSHOT_KIND_NORMAL);
+	g_assert_cmpstr (as_screenshot_get_caption (screenshot, "C"), ==, "Hello");
+	images = as_screenshot_get_images (screenshot);
+	g_assert_cmpint (images->len, ==, 2);
+	as_node_unref (root);
+
+	/* back to node */
+	root = as_node_new ();
+	n = as_screenshot_node_insert (screenshot, root);
+	xml = as_node_to_xml (n, AS_NODE_TO_XML_FLAG_NONE);
+	g_assert_cmpstr (xml->str, ==, src);
+	g_string_free (xml, TRUE);
+	as_node_unref (root);
+
+	g_object_unref (screenshot);
+}
 
 static void
 ch_test_app_func (void)
 {
 	AsApp *app;
+	GError *error = NULL;
+	GNode *n;
+	GNode *root;
+	GString *xml;
+	gboolean ret;
+	const gchar *src =
+		"<application>"
+		"<id type=\"desktop\">org.gnome.Software.desktop</id>"
+		"<pkgname>gnome-software</pkgname>"
+		"<name>Software</name>"
+		"<name xml:lang=\"pl\">Oprogramowanie</name>"
+		"<summary>Application manager</summary>"
+		"<description><p>Software allows you to find stuff</p></description>"
+		"<description xml:lang=\"pt_BR\"><p>O aplicativo Software.</p></description>"
+		"<icon type=\"cached\">org.gnome.Software.png</icon>"
+		"<appcategories>"
+		"<appcategory>System</appcategory>"
+		"</appcategories>"
+		"<project_license>GPLv2+</project_license>"
+		"<url type=\"homepage\">https://wiki.gnome.org/Design/Apps/Software</url>"
+		"<project_group>GNOME</project_group>"
+		"<compulsory_for_desktop>GNOME</compulsory_for_desktop>"
+		"<screenshots>"
+		"<screenshot type=\"default\">"
+		"<image type=\"thumbnail\" height=\"351\" width=\"624\">http://a.png</image>"
+		"</screenshot>"
+		"<screenshot type=\"normal\">"
+		"<image type=\"thumbnail\">http://b.png</image>"
+		"</screenshot>"
+		"</screenshots>"
+		"<releases>"
+		"<release version=\"3.11.90\" timestamp=\"1392724800\"/>"
+		"</releases>"
+		"<metadata>"
+		"<value key=\"X-Kudo-GTK3\"/>"
+		"</metadata>"
+		"</application>";
+
 	app = as_app_new ();
+
+	/* to object */
+	root = as_node_from_xml (src, -1, &error);
+	g_assert_no_error (error);
+	g_assert (root != NULL);
+	n = as_node_find (root, "application");
+	g_assert (n != NULL);
+	ret = as_app_node_parse (app, n, &error);
+	g_assert_no_error (error);
+	g_assert (ret);
+
+	/* verify */
+	g_assert_cmpstr (as_app_get_id_full (app), ==, "org.gnome.Software.desktop");
+	g_assert_cmpstr (as_app_get_id (app), ==, "org.gnome.Software");
+	g_assert_cmpstr (as_app_get_name (app, "pl"), ==, "Oprogramowanie");
+	g_assert_cmpstr (as_app_get_comment (app, NULL), ==, "Application manager");
+	g_assert_cmpstr (as_app_get_icon (app), ==, "org.gnome.Software.png");
+	g_assert_cmpint (as_app_get_icon_kind (app), ==, AS_APP_ICON_KIND_CACHED);
+	g_assert_cmpstr (as_app_get_project_group (app), ==, "GNOME");
+	g_assert_cmpstr (as_app_get_project_license (app), ==, "GPLv2+");
+	g_assert_cmpint (as_app_get_categories(app)->len, ==, 1);
+	g_assert_cmpint (as_app_get_screenshots(app)->len, ==, 2);
+	g_assert_cmpint (as_app_get_releases(app)->len, ==, 1);
+	g_assert_cmpstr (as_app_get_metadata_item (app, "X-Kudo-GTK3"), ==, "");
+	as_node_unref (root);
+
+	/* back to node */
+	root = as_node_new ();
+	n = as_app_node_insert (app, root);
+	xml = as_node_to_xml (n, AS_NODE_TO_XML_FLAG_NONE);
+	g_assert_cmpstr (xml->str, ==, src);
+	g_string_free (xml, TRUE);
+	as_node_unref (root);
+
 	g_object_unref (app);
 }
 
@@ -252,6 +456,9 @@ main (int argc, char **argv)
 	g_log_set_fatal_mask (NULL, G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL);
 
 	/* tests go here */
+	g_test_add_func ("/AppStream/release", ch_test_release_func);
+	g_test_add_func ("/AppStream/image", ch_test_image_func);
+	g_test_add_func ("/AppStream/screenshot", ch_test_screenshot_func);
 	g_test_add_func ("/AppStream/app", ch_test_app_func);
 	g_test_add_func ("/AppStream/node", ch_test_node_func);
 	g_test_add_func ("/AppStream/node{xml}", ch_test_node_xml_func);