src/scripting/lua/hooks.c

   1 /* Lua scripting hooks */
   2
   3 #ifdef HAVE_CONFIG_H
   4 #include "config.h"
   5 #endif
   6
   7 #include <lauxlib.h>
   8 #include <lua.h>
   9 #include <lualib.h>
  10
  11 #include "elinks.h"
  12
  13 #include "cache/cache.h"
  14 #include "main/event.h"
  15 #include "protocol/uri.h"
  16 #include "scripting/lua/core.h"
  17 #include "scripting/lua/hooks.h"
  18 #include "session/location.h"
  19 #include "session/session.h"
  20 #include "util/string.h"
  21
  22
  23 /* The events that will trigger the functions below and what they are expected
  24  * to do is explained in doc/events.txt */
  25
  26 static enum evhook_status
  27 script_hook_goto_url(va_list ap, void *data)
  28 {
  29         lua_State *L = lua_state;
  30         unsigned char **url = va_arg(ap, unsigned char **);
  31         struct session *ses = va_arg(ap, struct session *);
  32         int err;
  33
  34         if (*url == NULL) return EVENT_HOOK_STATUS_NEXT;
  35
  36         lua_getglobal(L, "goto_url_hook");
  37         if (lua_isnil(L, -1)) {
  38                 /* The function is not defined */
  39                 lua_pop(L, 1);
  40                 return EVENT_HOOK_STATUS_NEXT;
  41         }
  42
  43         lua_pushstring(L, *url);
  44
  45         if (!ses || !have_location(ses)) {
  46                 lua_pushnil(L);
  47         } else {
  48                 lua_pushstring(L, struri(cur_loc(ses)->vs.uri));
  49         }
  50
  51         if (prepare_lua(ses)) return EVENT_HOOK_STATUS_NEXT;
  52
  53         err = lua_pcall(L, 2, 1, 0);
  54         finish_lua();
  55         if (err) return EVENT_HOOK_STATUS_NEXT;
  56
  57         if (lua_isstring(L, -1)) {
  58                 unsigned char *new_url;
  59
  60                 new_url = stracpy((unsigned char *) lua_tostring(L, -1));
  61                 if (new_url) {
  62                         mem_free_set(url, new_url);
  63                 }
  64         } else if (lua_isnil(L, -1)) {
  65                 (*url)[0] = 0;
  66         } else {
  67                 alert_lua_error("goto_url_hook must return a string or nil");
  68         }
  69
  70         lua_pop(L, 1);
  71
  72         return EVENT_HOOK_STATUS_NEXT;
  73 }
  74
  75 static enum evhook_status
  76 script_hook_follow_url(va_list ap, void *data)
  77 {
  78         lua_State *L = lua_state;
  79         unsigned char **url = va_arg(ap, unsigned char **);
  80         struct session *ses = va_arg(ap, struct session *);
  81         int err;
  82
  83         if (*url == NULL) return EVENT_HOOK_STATUS_NEXT;
  84
  85         lua_getglobal(L, "follow_url_hook");
  86         if (lua_isnil(L, -1)) {
  87                 /* The function is not defined */
  88                 lua_pop(L, 1);
  89                 return EVENT_HOOK_STATUS_NEXT;
  90         }
  91
  92         lua_pushstring(L, *url);
  93
  94         if (prepare_lua(ses)) return EVENT_HOOK_STATUS_NEXT;
  95
  96         err = lua_pcall(L, 1, 1, 0);
  97         finish_lua();
  98         if (err) return EVENT_HOOK_STATUS_NEXT;
  99
 100         if (lua_isstring(L, -1)) {
 101                 unsigned char *new_url;
 102
 103                 new_url = stracpy((unsigned char *) lua_tostring(L, -1));
 104                 if (new_url) {
 105                         mem_free_set(url, new_url);
 106                 }
 107         } else if (lua_isnil(L, -1)) {
 108                 (*url)[0] = 0;
 109         } else {
 110                 alert_lua_error("follow_url_hook must return a string or nil");
 111         }
 112
 113         lua_pop(L, 1);
 114
 115         return EVENT_HOOK_STATUS_NEXT;
 116 }
 117
 118 static enum evhook_status
 119 script_hook_pre_format_html(va_list ap, void *data)
 120 {
 121         lua_State *L = lua_state;
 122         struct session *ses = va_arg(ap, struct session *);
 123         struct cache_entry *cached = va_arg(ap, struct cache_entry *);
 124         struct fragment *fragment = get_cache_fragment(cached);
 125         unsigned char *url = struri(cached->uri);
 126         int err;
 127
 128         if (!cached->length || !*fragment->data) return EVENT_HOOK_STATUS_NEXT;
 129
 130         lua_getglobal(L, "pre_format_html_hook");
 131         if (lua_isnil(L, -1)) {
 132                 /* The function is not defined */
 133                 lua_pop(L, 1);
 134                 return EVENT_HOOK_STATUS_NEXT;
 135         }
 136
 137         lua_pushstring(L, url);
 138         lua_pushlstring(L, fragment->data, fragment->length);
 139
 140         if (prepare_lua(ses)) return EVENT_HOOK_STATUS_NEXT;
 141
 142         err = lua_pcall(L, 2, 1, 0);
 143         finish_lua();
 144         if (err) return EVENT_HOOK_STATUS_NEXT;
 145
 146         if (lua_isstring(L, -1)) {
 147                 int len = lua_strlen(L, -1);
 148
 149                 add_fragment(cached, 0, (unsigned char *) lua_tostring(L, -1), len);
 150                 normalize_cache_entry(cached, len);
 151         } else if (!lua_isnil(L, -1)) {
 152                 alert_lua_error("pre_format_html_hook must return a string or nil");
 153         }
 154
 155         lua_pop(L, 1);
 156
 157         return EVENT_HOOK_STATUS_NEXT;
 158 }
 159
 160 /* The Lua function can return:
 161  *  - "PROXY:PORT" to use the specified proxy
 162  *  - ""           to not use any proxy
 163  *  - nil          to use the default proxies */
 164 static enum evhook_status
 165 script_hook_get_proxy(va_list ap, void *data)
 166 {
 167         lua_State *L = lua_state;
 168         unsigned char **new_proxy_url = va_arg(ap, unsigned char **);
 169         unsigned char *url = va_arg(ap, unsigned char *);
 170         int err;
 171
 172         if (!new_proxy_url || !url)
 173                 return EVENT_HOOK_STATUS_NEXT;
 174
 175         lua_getglobal(L, "proxy_for_hook");
 176         if (lua_isnil(L, -1)) {
 177                 /* The function is not defined */
 178                 lua_pop(L, 1);
 179                 return EVENT_HOOK_STATUS_NEXT;
 180         }
 181
 182         lua_pushstring(L, url);
 183         if (prepare_lua(NULL)) return EVENT_HOOK_STATUS_NEXT;
 184
 185         err = lua_pcall(L, 1, 1, 0);
 186         finish_lua();
 187         if (err) return EVENT_HOOK_STATUS_NEXT;
 188
 189         if (lua_isstring(L, -1)) {
 190                 mem_free_set(new_proxy_url,
 191                              stracpy((unsigned char *) lua_tostring(L, -1)));
 192         } else if (lua_isnil(L, -1)) {
 193                 mem_free_set(new_proxy_url, NULL);
 194         } else {
 195                 alert_lua_error("proxy_hook must return a string or nil");
 196         }
 197
 198         lua_pop(L, 1);
 199
 200         return EVENT_HOOK_STATUS_NEXT;
 201 }
 202
 203 static enum evhook_status
 204 script_hook_quit(va_list ap, void *data)
 205 {
 206         if (!prepare_lua(NULL)) {
 207                 (void)luaL_dostring(lua_state, "if quit_hook then quit_hook() end");
 208                 finish_lua();
 209         }
 210
 211         return EVENT_HOOK_STATUS_NEXT;
 212 }
 213
 214 struct event_hook_info lua_scripting_hooks[] = {
 215         { "goto-url", 0, script_hook_goto_url, NULL },
 216         { "follow-url", 0, script_hook_follow_url, NULL },
 217         { "pre-format-html", 0, script_hook_pre_format_html, NULL },
 218         { "get-proxy", 0, script_hook_get_proxy, NULL },
 219         { "quit", 0, script_hook_quit, NULL },
 220         { "dialog-lua-console", 0, dialog_lua_console, NULL },
 221         { "free-history", 0, free_lua_console_history, NULL },
 222         NULL_EVENT_HOOK_INFO,
 223 };