aboutsummaryrefslogtreecommitdiffstats
path: root/e-util/e-plugin.c
blob: 7fd4778b9a21a19429a45e60e757396a8755b48e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/types.h>
#include <string.h>

#include <glib/gi18n.h>

#include <libebackend/libebackend.h>

#include "e-plugin.h"
#include "e-util-private.h"

/* plugin debug */
#define pd(x)
/* plugin hook debug */
#define phd(x)

/*
 * <camel-plugin
 *   class="org.gnome.camel.plugin.provider:1.0"
 *   id="org.gnome.camel.provider.imap:1.0"
 *   type="shlib"
 *   location="/opt/gnome2/lib/camel/1.0/libcamelimap.so"
 *   factory="camel_imap_provider_new">
 *  <name>imap</name>
 *  <description>IMAP4 and IMAP4v1 mail store</description>
 *  <class-data class="org.gnome.camel.plugin.provider:1.0"
 *    protocol="imap"
 *    domain="mail"
 *    flags="remote,source,storage,ssl"/>
 * </camel-plugin>
 * 
 * <camel-plugin
 *   class="org.gnome.camel.plugin.sasl:1.0"
 *   id="org.gnome.camel.sasl.plain:1.0"
 *   type="shlib"
 *   location="/opt/gnome2/lib/camel/1.0/libcamelsasl.so"
 *   factory="camel_sasl_plain_new">
 *  <name>PLAIN</name>
 *  <description>SASL PLAIN authentication mechanism</description>
 * </camel-plugin>
*/

/* EPlugin stuff */

/* global table of plugin types by pluginclass.type */
static GHashTable *ep_types;
/* global table of plugins by plugin.id */
static GHashTable *ep_plugins;
/* the list of disabled plugins from GSettings */
static GSList *ep_disabled;

/* All classes which implement EPluginHooks, by class.id */
static GHashTable *eph_types;

struct _plugin_doc {
    struct _plugin_doc *next;
    struct _plugin_doc *prev;

    gchar *filename;
    xmlDocPtr doc;
};

enum {
    EP_PROP_0,
    EP_PROP_ENABLED
};

G_DEFINE_TYPE (
    EPlugin,
    e_plugin,
    G_TYPE_OBJECT)

static gboolean
ep_check_enabled (const gchar *id)
{
    /* Return TRUE if 'id' is NOT in the disabled list. */
    return !g_slist_find_custom (ep_disabled, id, (GCompareFunc) strcmp);
}

static void
ep_set_enabled (const gchar *id,
                gint state)
{
    GSettings *settings;
    GSList *link;
    GPtrArray *array;

    /* Bail out if no change to state, when expressed as a boolean: */
    if ((state == 0) == (ep_check_enabled (id) == 0))
        return;

    if (state) {
        GSList *link;

        link = g_slist_find_custom (
            ep_disabled, id, (GCompareFunc) strcmp);
        if (link != NULL) {
            g_free (link->data);
            ep_disabled = g_slist_remove_link (ep_disabled, link);
        }
    } else
        ep_disabled = g_slist_prepend (ep_disabled, g_strdup (id));

    settings = g_settings_new ("org.gnome.evolution");
    array = g_ptr_array_new ();
    for (link = ep_disabled; link != NULL; link = link->next)
        g_ptr_array_add (array, link->data);
    g_ptr_array_add (array, NULL);
    g_settings_set_strv (
        settings, "disabled-eplugins",
        (const gchar * const *) array->pdata);
    g_ptr_array_free (array, TRUE);
    g_object_unref (settings);
}

static gint
ep_construct (EPlugin *ep,
              xmlNodePtr root)
{
    xmlNodePtr node;
    gint res = -1;
    gchar *localedir;

    ep->domain = e_plugin_xml_prop (root, "domain");
    if (ep->domain
        && (localedir = e_plugin_xml_prop (root, "localedir"))) {
#ifdef G_OS_WIN32
        gchar *mapped_localedir =
            e_util_replace_prefix (
                EVOLUTION_PREFIX,
                e_util_get_prefix (),
                localedir);
        g_free (localedir);
        localedir = mapped_localedir;
#endif
        bindtextdomain (ep->domain, localedir);
        g_free (localedir);
    }

    ep->name = e_plugin_xml_prop_domain (root, "name", ep->domain);

    node = root->children;
    while (node) {
        if (strcmp ((gchar *) node->name, "hook") == 0) {
            EPluginHook *hook;
            EPluginHookClass *type;
            gchar *class = e_plugin_xml_prop (node, "class");

            if (class == NULL) {
                g_warning (
                    "Plugin '%s' load failed in '%s', "
                    "missing class property for hook",
                    ep->id, ep->path);
                goto fail;
            }

            if (ep->enabled
                && eph_types != NULL
                && (type = g_hash_table_lookup (
                    eph_types, class)) != NULL) {
                g_free (class);
                hook = g_object_new (G_OBJECT_CLASS_TYPE (type), NULL);
                res = type->construct (hook, ep, node);
                if (res == -1) {
                    g_warning (
                        "Plugin '%s' failed to "
                        "load hook", ep->name);
                    g_object_unref (hook);
                    goto fail;
                } else {
                    ep->hooks = g_slist_append (ep->hooks, hook);
                }
            } else {
                g_free (class);
            }
        } else if (strcmp ((gchar *) node->name, "description") == 0) {
            ep->description =
                e_plugin_xml_content_domain (node, ep->domain);
        } else if (strcmp ((gchar *) node->name, "author") == 0) {
            gchar *name = e_plugin_xml_prop (node, "name");
            gchar *email = e_plugin_xml_prop (node, "email");

            if (name || email) {
                EPluginAuthor *epa = g_malloc0 (sizeof (*epa));

                epa->name = name;
                epa->email = email;
                ep->authors = g_slist_append (ep->authors, epa);
            }
        }
        node = node->next;
    }
    res = 0;
fail:
    return res;
}

static void
ep_enable (EPlugin *ep,
           gint state)
{
    GSList *iter;

    ep->enabled = state;
    for (iter = ep->hooks; iter != NULL; iter = iter->next) {
        EPluginHook *hook = iter->data;
        e_plugin_hook_enable (hook, state);
    }

    ep_set_enabled (ep->id, state);
}

static void
ep_set_property (GObject *object,
                 guint property_id,
                 const GValue *value,
                 GParamSpec *pspec)
{
    switch (property_id) {
        case EP_PROP_ENABLED:
            e_plugin_enable (
                E_PLUGIN (object),
                g_value_get_boolean (value));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
ep_get_property (GObject *object,
                 guint property_id,
                 GValue *value,
                 GParamSpec *pspec)
{
    EPlugin *ep = E_PLUGIN (object);

    switch (property_id) {
        case EP_PROP_ENABLED:
            g_value_set_boolean (value, ep->enabled);
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
ep_finalize (GObject *object)
{
    EPlugin *ep = E_PLUGIN (object);

    g_free (ep->id);
    g_free (ep->description);
    g_free (ep->name);
    g_free (ep->domain);

    g_slist_foreach (ep->hooks, (GFunc) g_object_unref, NULL);
    g_slist_free (ep->hooks);

    /* Chain up to parent's finalize() method. */
    G_OBJECT_CLASS (e_plugin_parent_class)->finalize (object);
}

static void
e_plugin_class_init (EPluginClass *class)
{
    GObjectClass *object_class;

    object_class = G_OBJECT_CLASS (class);
    object_class->set_property = ep_set_property;
    object_class->get_property = ep_get_property;
    object_class->finalize = ep_finalize;

    class->construct = ep_construct;
    class->enable = ep_enable;

    g_object_class_install_property (
        object_class,
        EP_PROP_ENABLED,
        g_param_spec_boolean (
            "enabled",
            "Enabled",
            "Whether the plugin is enabled",
            TRUE,
            G_PARAM_READWRITE));
}

static void
e_plugin_init (EPlugin *ep)
{
    ep->enabled = TRUE;
}

static EPlugin *
ep_load_plugin (xmlNodePtr root,
                struct _plugin_doc *pdoc)
{
    gchar *prop, *id;
    EPluginClass *class;
    EPlugin *ep;

    id = e_plugin_xml_prop (root, "id");
    if (id == NULL) {
        g_warning ("Invalid e-plugin entry in '%s': no id", pdoc->filename);
        return NULL;
    }

    if (g_hash_table_lookup (ep_plugins, id)) {
        g_warning ("Plugin '%s' already defined", id);
        g_free (id);
        return NULL;
    }

    prop = (gchar *) xmlGetProp (root, (const guchar *)"type");
    if (prop == NULL) {
        g_free (id);
        g_warning ("Invalid e-plugin entry in '%s': no type", pdoc->filename);
        return NULL;
    }

    /* If we can't find a plugin, add it to a pending list
     * which is checked when a new type is registered. */
    class = g_hash_table_lookup (ep_types, prop);
    if (class == NULL) {
        g_free (id);
        xmlFree (prop);
        return NULL;
    }
    xmlFree (prop);

    ep = g_object_new (G_TYPE_FROM_CLASS (class), NULL);
    ep->id = id;
    ep->path = g_strdup (pdoc->filename);
    ep->enabled = ep_check_enabled (id);
    if (e_plugin_construct (ep, root) == -1)
        e_plugin_enable (ep, FALSE);
    g_hash_table_insert (ep_plugins, ep->id, ep);

    return ep;
}

static gint
ep_load (const gchar *filename,
         gint load_level)
{
    xmlDocPtr doc;
    xmlNodePtr root;
    EPlugin *ep = NULL;
    struct _plugin_doc *pdoc;

    doc = e_xml_parse_file (filename);
    if (doc == NULL)
        return -1;

    root = xmlDocGetRootElement (doc);
    if (strcmp ((gchar *) root->name, "e-plugin-list") != 0) {
        g_warning ("No <e-plugin-list> root element: %s", filename);
        xmlFreeDoc (doc);
        return -1;
    }

    pdoc = g_malloc0 (sizeof (*pdoc));
    pdoc->doc = doc;
    pdoc->filename = g_strdup (filename);

    for (root = root->children; root; root = root->next) {
        if (strcmp ((gchar *) root->name, "e-plugin") == 0) {
            gchar *plugin_load_level, *is_system_plugin;

            plugin_load_level = NULL;
            plugin_load_level = e_plugin_xml_prop (root, "load_level");
            if (plugin_load_level) {
                if ((atoi (plugin_load_level) == load_level)) {
                    ep = ep_load_plugin (root, pdoc);

                    if (ep && load_level == 1)
                        e_plugin_invoke (
                            ep, "load_plugin_type_register_function", NULL);
                }
            } else if (load_level == 2) {
                ep = ep_load_plugin (root, pdoc);
            }

            if (ep) {
                /* README: Maybe we can use load_levels to
                 * achieve the same thing.  But it may be
                 * confusing for a plugin writer. */
                is_system_plugin =
                    e_plugin_xml_prop (root, "system_plugin");
                if (g_strcmp0 (is_system_plugin, "true") == 0) {
                    e_plugin_enable (ep, TRUE);
                    ep->flags |= E_PLUGIN_FLAGS_SYSTEM_PLUGIN;
                } else
                    ep->flags &= ~E_PLUGIN_FLAGS_SYSTEM_PLUGIN;
                g_free (is_system_plugin);

                ep = NULL;
            }
        }
    }

    xmlFreeDoc (pdoc->doc);
    g_free (pdoc->filename);
    g_free (pdoc);

    return 0;
}

static void
plugin_load_subclass (GType type,
                      GHashTable *hash_table)
{
    EPluginClass *class;

    class = g_type_class_ref (type);
    g_hash_table_insert (hash_table, (gpointer) class->type, class);
}

static void
plugin_hook_load_subclass (GType type,
                           GHashTable *hash_table)
{
    EPluginHookClass *hook_class;
    EPluginHookClass *dupe_class;
    gpointer key;

    hook_class = g_type_class_ref (type);

    /* Sanity check the hook class. */
    if (hook_class->id == NULL || *hook_class->id == '\0') {
        g_warning (
            "%s has no hook ID, so skipping",
            G_OBJECT_CLASS_NAME (hook_class));
        g_type_class_unref (hook_class);
        return;
    }

    /* Check for class ID collisions. */
    dupe_class = g_hash_table_lookup (hash_table, hook_class->id);
    if (dupe_class != NULL) {
        g_warning (
            "%s and %s have the same hook "
            "ID ('%s'), so skipping %s",
            G_OBJECT_CLASS_NAME (dupe_class),
            G_OBJECT_CLASS_NAME (hook_class),
            hook_class->id,
            G_OBJECT_CLASS_NAME (hook_class));
        g_type_class_unref (hook_class);
        return;
    }

    key = (gpointer) hook_class->id;
    g_hash_table_insert (hash_table, key, hook_class);
}

/**
 * e_plugin_load_plugins:
 *
 * Scan the search path, looking for plugin definitions, and load them
 * into memory.
 *
 * Return value: Returns -1 if an error occurred.
 **/
gint
e_plugin_load_plugins (void)
{
    GSettings *settings;
    gchar **strv;
    gint i;

    if (eph_types != NULL)
        return 0;

    ep_types = g_hash_table_new (g_str_hash, g_str_equal);
    eph_types = g_hash_table_new (g_str_hash, g_str_equal);
    ep_plugins = g_hash_table_new (g_str_hash, g_str_equal);

    /* We require that all GTypes for EPlugin and EPluginHook
     * subclasses be registered prior to loading any plugins.
     * It greatly simplifies the loading process. */
    e_type_traverse (
        E_TYPE_PLUGIN, (ETypeFunc)
        plugin_load_subclass, ep_types);
    e_type_traverse (
        E_TYPE_PLUGIN_HOOK, (ETypeFunc)
        plugin_hook_load_subclass, eph_types);

    settings = g_settings_new ("org.gnome.evolution");
    strv = g_settings_get_strv (settings, "disabled-eplugins");
    for (i = 0, ep_disabled = NULL; strv[i] != NULL; i++)
        ep_disabled = g_slist_append (ep_disabled, g_strdup (strv[i]));
    g_strfreev (strv);
    g_object_unref (settings);

    for (i = 0; i < 3; i++) {
        GDir *dir;
        const gchar *d;
        const gchar *path = EVOLUTION_PLUGINDIR;

        pd (printf ("scanning plugin dir '%s'\n", path));

        dir = g_dir_open (path, 0, NULL);
        if (dir == NULL) {
            /*g_warning("Could not find plugin path: %s", path);*/
            continue;
        }

        while ((d = g_dir_read_name (dir))) {
            if (g_str_has_suffix  (d, ".eplug")) {
                gchar *name;

                name = g_build_filename (path, d, NULL);
                ep_load (name, i);
                g_free (name);
            }
        }

        g_dir_close (dir);
    }

    return 0;
}

static void
ep_list_plugin (gpointer key,
                gpointer val,
                gpointer dat)
{
    GSList **l = (GSList **) dat;

    *l = g_slist_prepend(*l, g_object_ref(val));
}

/**
 * e_plugin_list_plugins: List all plugins.
 *
 * Static class method to retrieve a list of all current plugins.  They
 * are listed in no particular order.
 *
 * Return value: A GSList of all plugins, they must be
 * g_object_unref'd and the list freed.
 **/
GSList *
e_plugin_list_plugins (void)
{
    GSList *l = NULL;

    if (ep_plugins)
        g_hash_table_foreach (ep_plugins, ep_list_plugin, &l);

    return l;
}

/**
 * e_plugin_construct:
 * @plugin: an #EPlugin
 * @root: The XML root node of the sub-tree containing the plugin
 * definition.
 *
 * Helper to invoke the construct virtual method.
 *
 * Return value: The return from the construct virtual method.
 **/
gint
e_plugin_construct (EPlugin *plugin,
                    xmlNodePtr root)
{
    EPluginClass *class;

    g_return_val_if_fail (E_IS_PLUGIN (plugin), -1);

    class = E_PLUGIN_GET_CLASS (plugin);
    g_return_val_if_fail (class->construct != NULL, -1);

    return class->construct (plugin, root);
}

/**
 * e_plugin_invoke:
 * @plugin: an #EPlugin
 * @name: The name of the function to invoke. The format of this name
 * will depend on the EPlugin type and its language conventions.
 * @data: The argument to the function. Its actual type depends on
 * the hook on which the function resides. It is up to the called
 * function to get this right.
 *
 * Helper to invoke the invoke virtual method.
 *
 * Return value: The return of the plugin invocation.
 **/
gpointer
e_plugin_invoke (EPlugin *plugin,
                 const gchar *name,
                 gpointer data)
{
    EPluginClass *class;

    g_return_val_if_fail (E_IS_PLUGIN (plugin), NULL);
    g_return_val_if_fail (name != NULL, NULL);

    /* Prevent invocation on a disabled plugin. */
    g_return_val_if_fail (plugin->enabled, NULL);

    class = E_PLUGIN_GET_CLASS (plugin);
    g_return_val_if_fail (class->invoke != NULL, NULL);

    return class->invoke (plugin, name, data);
}

/**
 * e_plugin_get_symbol:
 * @plugin: an #EPlugin
 * @name: The name of the symbol to fetch. The format of this name
 * will depend on the EPlugin type and its language conventions.
 *
 * Helper to fetch a symbol name from a plugin.
 *
 * Return value: the symbol value, or %NULL if not found
 **/
gpointer
e_plugin_get_symbol (EPlugin *plugin,
                     const gchar *name)
{
    EPluginClass *class;

    g_return_val_if_fail (E_IS_PLUGIN (plugin), NULL);

    class = E_PLUGIN_GET_CLASS (plugin);
    g_return_val_if_fail (class->get_symbol != NULL, NULL);

    return class->get_symbol (plugin, name);
}

/**
 * e_plugin_enable:
 * @plugin: an #EPlugin
 * @state: %TRUE to enable, %FALSE to disable
 *
 * Set the enable state of a plugin.
 *
 * THIS IS NOT FULLY IMPLEMENTED YET
 **/
void
e_plugin_enable (EPlugin *plugin,
                 gint state)
{
    EPluginClass *class;

    g_return_if_fail (E_IS_PLUGIN (plugin));

    if ((plugin->enabled == 0) == (state == 0))
        return;

    class = E_PLUGIN_GET_CLASS (plugin);
    g_return_if_fail (class->enable != NULL);

    class->enable (plugin, state);

    g_object_notify (G_OBJECT (plugin), "enabled");
}

/**
 * e_plugin_get_configure_widget
 * @plugin: an #EPlugin
 *
 * Plugin itself should have implemented "e_plugin_lib_get_configure_widget"
 * function * of prototype EPluginLibGetConfigureWidgetFunc.
 *
 * Returns: Configure widget or %NULL
 **/
GtkWidget *
e_plugin_get_configure_widget (EPlugin *plugin)
{
    EPluginClass *class;

    g_return_val_if_fail (E_IS_PLUGIN (plugin), NULL);

    class = E_PLUGIN_GET_CLASS (plugin);
    if (class->get_configure_widget == NULL)
        return NULL;

    return class->get_configure_widget (plugin);
}

/**
 * e_plugin_xml_prop:
 * @node: An XML node.
 * @id: The name of the property to retrieve.
 *
 * A static helper function to look up a property on an XML node, and
 * ensure it is allocated in GLib system memory.
 *
 * Return value: The property, allocated in GLib memory, or NULL if no
 * such property exists.
 **/
gchar *
e_plugin_xml_prop (xmlNodePtr node,
                   const gchar *id)
{
    xmlChar *xml_prop;
    gchar *glib_prop = NULL;

    xml_prop = xmlGetProp (node, (xmlChar *) id);

    if (xml_prop != NULL) {
        glib_prop = g_strdup ((gchar *) xml_prop);
        xmlFree (xml_prop);
    }

    return glib_prop;
}

/**
 * e_plugin_xml_prop_domain:
 * @node: An XML node.
 * @id: The name of the property to retrieve.
 * @domain: The translation domain for this string.
 *
 * A static helper function to look up a property on an XML node, and
 * translate it based on @domain.
 *
 * Return value: The property, allocated in GLib memory, or NULL if no
 * such property exists.
 **/
gchar *
e_plugin_xml_prop_domain (xmlNodePtr node,
                          const gchar *id,
                          const gchar *domain)
{
    gchar *p, *out;

    p = (gchar *) xmlGetProp (node, (const guchar *) id);
    if (p == NULL)
        return NULL;

    out = g_strdup (dgettext (domain, p));
    xmlFree (p);

    return out;
}

/**
 * e_plugin_xml_int:
 * @node: An XML node.
 * @id: The name of the property to retrieve.
 * @def: A default value if the property doesn't exist.  Can be used
 * to determine if the property isn't set.
 *
 * A static helper function to look up a property on an XML node as an
 * integer.  If the property doesn't exist, then @def is returned as a
 * default value instead.
 *
 * Return value: The value if set, or @def if not.
 **/
gint
e_plugin_xml_int (xmlNodePtr node,
                  const gchar *id,
                  gint def)
{
    gchar *p = (gchar *) xmlGetProp (node, (const guchar *) id);

    if (p)
        return atoi (p);
    else
        return def;
}

/**
 * e_plugin_xml_content:
 * @node:
 *
 * A static helper function to retrieve the entire textual content of
 * an XML node, and ensure it is allocated in GLib system memory.  If
 * GLib isn't using the system malloc them it must copy the content.
 *
 * Return value: The node content, allocated in GLib memory.
 **/
gchar *
e_plugin_xml_content (xmlNodePtr node)
{
    gchar *p = (gchar *) xmlNodeGetContent (node);

    if (g_mem_is_system_malloc ()) {
        return p;
    } else {
        gchar * out = g_strdup (p);

        if (p)
            xmlFree (p);
        return out;
    }
}

/**
 * e_plugin_xml_content_domain:
 * @node:
 * @domain:
 *
 * A static helper function to retrieve the entire textual content of
 * an XML node, and ensure it is allocated in GLib system memory.  If
 * GLib isn't using the system malloc them it must copy the content.
 *
 * Return value: The node content, allocated in GLib memory.
 **/
gchar *
e_plugin_xml_content_domain (xmlNodePtr node,
                             const gchar *domain)
{
    gchar *p, *out;

    p = (gchar *) xmlNodeGetContent (node);
    if (p == NULL)
        return NULL;

    out = g_strdup (dgettext (domain, p));
    xmlFree (p);

    return out;
}

/* ********************************************************************** */

G_DEFINE_TYPE (
    EPluginHook,
    e_plugin_hook,
    G_TYPE_OBJECT)

static gint
plugin_hook_construct (EPluginHook *plugin_hook,
                       EPlugin *plugin,
                       xmlNodePtr root)
{
    plugin_hook->plugin = plugin;

    return 0;
}

static void
plugin_hook_enable (EPluginHook *plugin_hook,
                    gint state)
{
    /* NOOP */
}

static void
e_plugin_hook_class_init (EPluginHookClass *class)
{
    class->construct = plugin_hook_construct;
    class->enable = plugin_hook_enable;
}

static void
e_plugin_hook_init (EPluginHook *hook)
{
}

/**
 * e_plugin_hook_enable:
 * @plugin_hook:
 * @state:
 *
 * Set the enabled state of the plugin hook.  This is called by the
 * plugin code.
 *
 * THIS IS NOT FULY IMEPLEMENTED YET
 **/
void
e_plugin_hook_enable (EPluginHook *plugin_hook,
                      gint state)
{
    EPluginHookClass *class;

    g_return_if_fail (E_IS_PLUGIN_HOOK (plugin_hook));

    class = E_PLUGIN_HOOK_GET_CLASS (plugin_hook);
    g_return_if_fail (class->enable != NULL);

    class->enable (plugin_hook, state);
}

/**
 * e_plugin_hook_mask:
 * @root: An XML node.
 * @map: A zero-fill terminated array of EPluginHookTargeKeys used to
 * map a string with a bit value.
 * @prop: The property name.
 *
 * This is a static helper function which looks up a property @prop on
 * the XML node @root, and then uses the @map table to convert it into
 * a bitmask.  The property value is a comma separated list of
 * enumeration strings which are indexed into the @map table.
 *
 * Return value: A bitmask representing the inclusive-or of all of the
 * integer values of the corresponding string id's stored in the @map.
 **/
guint32
e_plugin_hook_mask (xmlNodePtr root,
                    const EPluginHookTargetKey *map,
                    const gchar *prop)
{
    gchar *val, *p, *start, c;
    guint32 mask = 0;

    val = (gchar *) xmlGetProp (root, (const guchar *) prop);
    if (val == NULL)
        return 0;

    p = val;
    do {
        start = p;
        while (*p && *p != ',')
            p++;
        c = *p;
        *p = 0;
        if (start != p) {
            gint i;

            for (i = 0; map[i].key; i++) {
                if (!strcmp (map[i].key, start)) {
                    mask |= map[i].value;
                    break;
                }
            }
        }
        *p++ = c;
    } while (c);

    xmlFree (val);

    return mask;
}

/**
 * e_plugin_hook_id:
 * @root:
 * @map:
 * @prop:
 *
 * This is a static helper function which looks up a property @prop on
 * the XML node @root, and then uses the @map table to convert it into
 * an integer.
 *
 * This is used as a helper wherever you need to represent an
 * enumerated value in the XML.
 *
 * Return value: If the @prop value is in @map, then the corresponding
 * integer value, if not, then ~0.
 **/
guint32
e_plugin_hook_id (xmlNodePtr root,
                  const EPluginHookTargetKey *map,
                  const gchar *prop)
{
    gchar *val;
    gint i;

    val = (gchar *) xmlGetProp (root, (const guchar *) prop);
    if (val == NULL)
        return ~0;

    for (i = 0; map[i].key; i++) {
        if (!strcmp (map[i].key, val)) {
            xmlFree (val);
            return map[i].value;
        }
    }

    xmlFree (val);

    return ~0;
}