1 /* json-gobject.c - JSON GObject integration
2  *
3  * This file is part of JSON-GLib
4  * Copyright (C) 2007  OpenedHand Ltd.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * Author:
17  *   Emmanuele Bassi  <ebassi@openedhand.com>
18  */
19 
20 /**
21  * SECTION:json-serializable
22  * @short_description: Interface for serialize and deserialize special GObjects
23  *
24  * #JsonSerializable is an interface for #GObject classes that
25  * allows controlling how the class is going to be serialized
26  * or deserialized by json_construct_gobject() and
27  * json_serialize_gobject() respectively.
28  */
29 
30 #include "config.h"
31 
32 #include <string.h>
33 #include <stdlib.h>
34 
35 #include "json-types-private.h"
36 #include "json-gobject-private.h"
37 #include "json-debug.h"
38 
39 /**
40  * json_serializable_serialize_property:
41  * @serializable: a #JsonSerializable object
42  * @property_name: the name of the property
43  * @value: the value of the property
44  * @pspec: a #GParamSpec
45  *
46  * Asks a #JsonSerializable implementation to serialize a #GObject
47  * property into a #JsonNode object.
48  *
49  * Return value: a #JsonNode containing the serialized property
50  */
51 JsonNode *
json_serializable_serialize_property(JsonSerializable * serializable,const gchar * property_name,const GValue * value,GParamSpec * pspec)52 json_serializable_serialize_property (JsonSerializable *serializable,
53                                       const gchar      *property_name,
54                                       const GValue     *value,
55                                       GParamSpec       *pspec)
56 {
57   JsonSerializableIface *iface;
58 
59   g_return_val_if_fail (JSON_IS_SERIALIZABLE (serializable), NULL);
60   g_return_val_if_fail (property_name != NULL, NULL);
61   g_return_val_if_fail (value != NULL, NULL);
62   g_return_val_if_fail (pspec != NULL, NULL);
63 
64   iface = JSON_SERIALIZABLE_GET_IFACE (serializable);
65 
66   return iface->serialize_property (serializable, property_name, value, pspec);
67 }
68 
69 /**
70  * json_serializable_deserialize_property:
71  * @serializable: a #JsonSerializable
72  * @property_name: the name of the property
73  * @value: (out): a pointer to an uninitialized #GValue
74  * @pspec: a #GParamSpec
75  * @property_node: a #JsonNode containing the serialized property
76  *
77  * Asks a #JsonSerializable implementation to deserialize the
78  * property contained inside @property_node into @value.
79  *
80  * The @value can be:
81  * - an empty #GValue initialized by %G_VALUE_INIT, which will be automatically
82  *   initialized with the expected type of the property (since JSON-GLib 1.6)
83  * - a #GValue initialized with the expected type of the property
84  *
85  * Return value: %TRUE if the property was successfully deserialized.
86  */
87 gboolean
json_serializable_deserialize_property(JsonSerializable * serializable,const gchar * property_name,GValue * value,GParamSpec * pspec,JsonNode * property_node)88 json_serializable_deserialize_property (JsonSerializable *serializable,
89                                         const gchar      *property_name,
90                                         GValue           *value,
91                                         GParamSpec       *pspec,
92                                         JsonNode         *property_node)
93 {
94   JsonSerializableIface *iface;
95 
96   g_return_val_if_fail (JSON_IS_SERIALIZABLE (serializable), FALSE);
97   g_return_val_if_fail (property_name != NULL, FALSE);
98   g_return_val_if_fail (value != NULL, FALSE);
99   g_return_val_if_fail (pspec != NULL, FALSE);
100   g_return_val_if_fail (property_node != NULL, FALSE);
101 
102   iface = JSON_SERIALIZABLE_GET_IFACE (serializable);
103 
104   return iface->deserialize_property (serializable,
105                                       property_name,
106                                       value,
107                                       pspec,
108                                       property_node);
109 }
110 
111 static gboolean
json_serializable_real_deserialize(JsonSerializable * serializable,const gchar * name,GValue * value,GParamSpec * pspec,JsonNode * node)112 json_serializable_real_deserialize (JsonSerializable *serializable,
113                                     const gchar      *name,
114                                     GValue           *value,
115                                     GParamSpec       *pspec,
116                                     JsonNode         *node)
117 {
118   JSON_NOTE (GOBJECT, "Default deserialization for property '%s'", pspec->name);
119 
120   if (!G_IS_VALUE (value))
121     g_value_init (value, G_PARAM_SPEC_VALUE_TYPE (pspec));
122 
123   return json_deserialize_pspec (value, pspec, node);
124 }
125 
126 static JsonNode *
json_serializable_real_serialize(JsonSerializable * serializable,const gchar * name,const GValue * value,GParamSpec * pspec)127 json_serializable_real_serialize (JsonSerializable *serializable,
128                                   const gchar      *name,
129                                   const GValue     *value,
130                                   GParamSpec       *pspec)
131 {
132   JSON_NOTE (GOBJECT, "Default serialization for property '%s'", pspec->name);
133 
134   if (g_param_value_defaults (pspec, (GValue *)value))
135     return NULL;
136 
137   return json_serialize_pspec (value, pspec);
138 }
139 
140 static GParamSpec *
json_serializable_real_find_property(JsonSerializable * serializable,const char * name)141 json_serializable_real_find_property (JsonSerializable *serializable,
142                                       const char       *name)
143 {
144   return g_object_class_find_property (G_OBJECT_GET_CLASS (serializable), name);
145 }
146 
147 static GParamSpec **
json_serializable_real_list_properties(JsonSerializable * serializable,guint * n_pspecs)148 json_serializable_real_list_properties (JsonSerializable *serializable,
149                                         guint            *n_pspecs)
150 {
151   return g_object_class_list_properties (G_OBJECT_GET_CLASS (serializable), n_pspecs);
152 }
153 
154 static void
json_serializable_real_set_property(JsonSerializable * serializable,GParamSpec * pspec,const GValue * value)155 json_serializable_real_set_property (JsonSerializable *serializable,
156                                      GParamSpec       *pspec,
157                                      const GValue     *value)
158 {
159   g_object_set_property (G_OBJECT (serializable), pspec->name, value);
160 }
161 
162 static void
json_serializable_real_get_property(JsonSerializable * serializable,GParamSpec * pspec,GValue * value)163 json_serializable_real_get_property (JsonSerializable *serializable,
164                                      GParamSpec       *pspec,
165                                      GValue           *value)
166 {
167   g_object_get_property (G_OBJECT (serializable), pspec->name, value);
168 }
169 
170 /* typedef to satisfy G_DEFINE_INTERFACE's naming */
171 typedef JsonSerializableIface   JsonSerializableInterface;
172 
173 static void
json_serializable_default_init(JsonSerializableInterface * iface)174 json_serializable_default_init (JsonSerializableInterface *iface)
175 {
176   iface->serialize_property = json_serializable_real_serialize;
177   iface->deserialize_property = json_serializable_real_deserialize;
178   iface->find_property = json_serializable_real_find_property;
179   iface->list_properties = json_serializable_real_list_properties;
180   iface->set_property = json_serializable_real_set_property;
181   iface->get_property = json_serializable_real_get_property;
182 }
183 
184 G_DEFINE_INTERFACE (JsonSerializable, json_serializable, G_TYPE_OBJECT);
185 
186 /**
187  * json_serializable_default_serialize_property:
188  * @serializable: a #JsonSerializable object
189  * @property_name: the name of the property
190  * @value: the value of the property
191  * @pspec: a #GParamSpec
192  *
193  * Calls the default implementation of the #JsonSerializable
194  * #JsonSerializableIface.serialize_property() virtual function.
195  *
196  * This function can be used inside a custom implementation
197  * of the #JsonSerializableIface.serialize_property() virtual
198  * function in lieu of calling the default implementation
199  * through g_type_default_interface_peek():
200  *
201  * |[<!-- language="C" -->
202  *   JsonSerializable *iface;
203  *   JsonNode *node;
204  *
205  *   iface = g_type_default_interface_peek (JSON_TYPE_SERIALIZABLE);
206  *   node = iface->serialize_property (serializable, property_name,
207  *                                     value,
208  *                                     pspec);
209  * ]|
210  *
211  * Return value: (transfer full) (nullable): a #JsonNode containing the
212  *   serialized property, or %NULL if it should be omitted.
213  *
214  * Since: 0.10
215  */
216 JsonNode *
json_serializable_default_serialize_property(JsonSerializable * serializable,const gchar * property_name,const GValue * value,GParamSpec * pspec)217 json_serializable_default_serialize_property (JsonSerializable *serializable,
218                                               const gchar      *property_name,
219                                               const GValue     *value,
220                                               GParamSpec       *pspec)
221 {
222   g_return_val_if_fail (JSON_IS_SERIALIZABLE (serializable), NULL);
223   g_return_val_if_fail (property_name != NULL, NULL);
224   g_return_val_if_fail (value != NULL, NULL);
225   g_return_val_if_fail (pspec != NULL, NULL);
226 
227   return json_serializable_real_serialize (serializable,
228                                            property_name,
229                                            value, pspec);
230 }
231 
232 /**
233  * json_serializable_default_deserialize_property:
234  * @serializable: a #JsonSerializable
235  * @property_name: the name of the property
236  * @value: a pointer to an uninitialized #GValue
237  * @pspec: a #GParamSpec
238  * @property_node: a #JsonNode containing the serialized property
239  *
240  * Calls the default implementation of the #JsonSerializable
241  * deserialize_property() virtual function
242  *
243  * This function can be used inside a custom implementation
244  * of the deserialize_property() virtual function in lieu of:
245  *
246  * |[<!-- language="C" -->
247  *   JsonSerializable *iface;
248  *   gboolean res;
249  *
250  *   iface = g_type_default_interface_peek (JSON_TYPE_SERIALIZABLE);
251  *   res = iface->deserialize_property (serializable, property_name,
252  *                                      value,
253  *                                      pspec,
254  *                                      property_node);
255  * ]|
256  *
257  * Return value: %TRUE if the property was successfully deserialized.
258  *
259  * Since: 0.10
260  */
261 gboolean
json_serializable_default_deserialize_property(JsonSerializable * serializable,const gchar * property_name,GValue * value,GParamSpec * pspec,JsonNode * property_node)262 json_serializable_default_deserialize_property (JsonSerializable *serializable,
263                                                 const gchar      *property_name,
264                                                 GValue           *value,
265                                                 GParamSpec       *pspec,
266                                                 JsonNode         *property_node)
267 {
268   g_return_val_if_fail (JSON_IS_SERIALIZABLE (serializable), FALSE);
269   g_return_val_if_fail (property_name != NULL, FALSE);
270   g_return_val_if_fail (value != NULL, FALSE);
271   g_return_val_if_fail (pspec != NULL, FALSE);
272   g_return_val_if_fail (property_node != NULL, FALSE);
273 
274   return json_serializable_real_deserialize (serializable,
275                                              property_name,
276                                              value, pspec,
277                                              property_node);
278 }
279 
280 /**
281  * json_serializable_find_property:
282  * @serializable: a #JsonSerializable
283  * @name: the name of the property
284  *
285  * Calls the #JsonSerializableIface.find_property() implementation on
286  * the @serializable instance. *
287  *
288  * Return value: (nullable) (transfer none): the #GParamSpec for the property
289  *   or %NULL if no property was found
290  *
291  * Since: 0.14
292  */
293 GParamSpec *
json_serializable_find_property(JsonSerializable * serializable,const char * name)294 json_serializable_find_property (JsonSerializable *serializable,
295                                  const char       *name)
296 {
297   g_return_val_if_fail (JSON_IS_SERIALIZABLE (serializable), NULL);
298   g_return_val_if_fail (name != NULL, NULL);
299 
300   return JSON_SERIALIZABLE_GET_IFACE (serializable)->find_property (serializable, name);
301 }
302 
303 /**
304  * json_serializable_list_properties:
305  * @serializable: a #JsonSerializable
306  * @n_pspecs: (out): return location for the length of the array
307  *   of #GParamSpec returned by the function
308  *
309  * Calls the #JsonSerializableIface.list_properties() implementation on
310  * the @serializable instance.
311  *
312  * Return value: (array length=n_pspecs) (transfer container): an array
313  *   of #GParamSpec. Use g_free() to free the array when done.
314  *
315  * Since: 0.14
316  */
317 GParamSpec **
json_serializable_list_properties(JsonSerializable * serializable,guint * n_pspecs)318 json_serializable_list_properties (JsonSerializable *serializable,
319                                    guint            *n_pspecs)
320 {
321   g_return_val_if_fail (JSON_IS_SERIALIZABLE (serializable), NULL);
322 
323   return JSON_SERIALIZABLE_GET_IFACE (serializable)->list_properties (serializable, n_pspecs);
324 }
325 
326 /**
327  * json_serializable_set_property:
328  * @serializable: a #JsonSerializable
329  * @pspec: a #GParamSpec
330  * @value: the property value to set
331  *
332  * Calls the #JsonSerializableIface.set_property() implementation
333  * on the @serializable instance.
334  *
335  * Since: 0.14
336  */
337 void
json_serializable_set_property(JsonSerializable * serializable,GParamSpec * pspec,const GValue * value)338 json_serializable_set_property (JsonSerializable *serializable,
339                                 GParamSpec       *pspec,
340                                 const GValue     *value)
341 {
342   g_return_if_fail (JSON_IS_SERIALIZABLE (serializable));
343   g_return_if_fail (G_IS_PARAM_SPEC (pspec));
344   g_return_if_fail (value != NULL);
345 
346   JSON_SERIALIZABLE_GET_IFACE (serializable)->set_property (serializable,
347                                                             pspec,
348                                                             value);
349 }
350 
351 /**
352  * json_serializable_get_property:
353  * @serializable: a #JsonSerializable
354  * @pspec: a #GParamSpec
355  * @value: (out): return location for the property value
356  *
357  * Calls the #JsonSerializableIface.get_property() implementation
358  * on the @serializable instance.
359  *
360  * Since: 0.14
361  */
362 void
json_serializable_get_property(JsonSerializable * serializable,GParamSpec * pspec,GValue * value)363 json_serializable_get_property (JsonSerializable *serializable,
364                                 GParamSpec       *pspec,
365                                 GValue           *value)
366 {
367   g_return_if_fail (JSON_IS_SERIALIZABLE (serializable));
368   g_return_if_fail (G_IS_PARAM_SPEC (pspec));
369   g_return_if_fail (value != NULL);
370 
371   JSON_SERIALIZABLE_GET_IFACE (serializable)->get_property (serializable,
372                                                             pspec,
373                                                             value);
374 }
375