[json-glib: 1/3] Add new api json_reader_get_current_node

[Emmanuele Bassi <ebassi src gnome org>]

commit 39e6a1f5ccd25abba5b2f618cec772b24f40085f
Author: Frederic Martinsons <frederic martinsons sigfox com>
Date:   Sat Sep 10 08:44:40 2022 +0200

    Add new api json_reader_get_current_node
    
    This can be useful to extract a sub json structure
    during parsing of another (for example when we don't
    know in advance the format of this sub json and just
    want to pass it to another consumer).
    
    Closes #9
    
    Signed-off-by: Frederic Martinsons <frederic martinsons sigfox com>

 json-glib/json-reader.c  | 19 +++++++++++++++++++
 json-glib/json-reader.h  |  2 ++
 json-glib/tests/reader.c | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+)
---
diff --git a/json-glib/json-reader.c b/json-glib/json-reader.c
index cc10cc8..3e58853 100644
--- a/json-glib/json-reader.c
+++ b/json-glib/json-reader.c
@@ -1117,3 +1117,22 @@ json_reader_get_member_name (JsonReader *reader)
   return g_ptr_array_index (reader->priv->members,
                             reader->priv->members->len - 1);
 }
+
+/**
+ * json_reader_get_current_node:
+ * @reader: a reader
+ *
+ * Retrieves the reader node at the current position.
+ *
+ * Return value: (nullable) (transfer none): the current node of the reader
+ *
+ * Since: 1.8
+ */
+JsonNode *
+json_reader_get_current_node (JsonReader *reader)
+{
+  g_return_val_if_fail (JSON_IS_READER (reader), NULL);
+  json_reader_return_val_if_error_set (reader, NULL);
+
+  return reader->priv->current_node;
+}
diff --git a/json-glib/json-reader.h b/json-glib/json-reader.h
index 105e88c..9efe36c 100644
--- a/json-glib/json-reader.h
+++ b/json-glib/json-reader.h
@@ -152,6 +152,8 @@ JSON_AVAILABLE_IN_1_0
 gboolean               json_reader_get_boolean_value (JsonReader   *reader);
 JSON_AVAILABLE_IN_1_0
 gboolean               json_reader_get_null_value    (JsonReader   *reader);
+JSON_AVAILABLE_IN_1_8
+JsonNode *             json_reader_get_current_node  (JsonReader *reader);
 
 #ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (JsonReader, g_object_unref)
diff --git a/json-glib/tests/reader.c b/json-glib/tests/reader.c
index 947fbc9..2ad2ec6 100644
--- a/json-glib/tests/reader.c
+++ b/json-glib/tests/reader.c
@@ -9,6 +9,9 @@ static const gchar *test_base_object_data =
 static const gchar *test_reader_level_data =
 " { \"list\": { \"181195771\": { \"given_url\": \"http://www.gnome.org/json-glib-test\"; } } }";
 
+static const gchar *test_reader_current_node_data =
+" { \"object\": { \"subobject\": { \"key\": \"value\" } } }";
+
 /* https://bugzilla.gnome.org/show_bug.cgi?id=758580 */
 static const char *test_reader_null_value_data =
 "{ \"v\": null }";
@@ -239,6 +242,41 @@ test_reader_skip_bom (void)
   g_object_unref (parser);
 }
 
+static void
+test_reader_current_node (void)
+{
+  JsonParser *parser = json_parser_new ();
+  JsonReader *reader = json_reader_new (NULL);
+  JsonNode *current = NULL;
+  gchar* node_string = NULL;
+  const gchar* expected_data = "{\"subobject\":{\"key\":\"value\"}}";
+  GError *error = NULL;
+
+  g_assert_null (json_reader_get_current_node (reader));
+
+  json_parser_load_from_data (parser, test_reader_current_node_data, -1, &error);
+  g_assert_no_error (error);
+
+  json_reader_set_root (reader, json_parser_get_root (parser));
+
+  /* Grab the list */
+  g_assert_true (json_reader_read_member (reader, "object"));
+
+  /* Get the node at the current position */
+  current = json_reader_get_current_node (reader);
+  g_assert_nonnull (current);
+
+  /* Check that it contains the data waited */
+  node_string = json_to_string (current, FALSE);
+  g_assert_cmpstr (node_string, ==, expected_data);
+  g_free (node_string);
+
+  json_reader_end_member (reader);
+
+  g_clear_object (&reader);
+  g_clear_object (&parser);
+}
+
 int
 main (int   argc,
       char *argv[])
@@ -251,6 +289,7 @@ main (int   argc,
   g_test_add_func ("/reader/level", test_reader_level);
   g_test_add_func ("/reader/null-value", test_reader_null_value);
   g_test_add_func ("/reader/bom", test_reader_skip_bom);
+  g_test_add_func ("/reader/currrent-node", test_reader_current_node);
 
   return g_test_run ();
 }