diff options
Diffstat (limited to 'src/Dom/Dom.c')
| -rw-r--r-- | src/Dom/Dom.c | 256 |
1 files changed, 235 insertions, 21 deletions
diff --git a/src/Dom/Dom.c b/src/Dom/Dom.c index 67817aa..3a70f61 100644 --- a/src/Dom/Dom.c +++ b/src/Dom/Dom.c @@ -243,66 +243,270 @@ static int node_has_class(lua_State *lua, int node_index, const char *wanted, return matches; } -static int push_first_by_class(lua_State *lua, int node_index, - const char *wanted, size_t wanted_length) { +typedef struct { + const char *tag; + size_t tag_length; + const char *id; + size_t id_length; + const char *suffixes; + size_t suffixes_length; +} CssSelector; + +static int is_selector_delimiter(char character) { + return character == '.' || character == '#'; +} + +static int is_unsupported_selector_character(char character) { + return is_html_whitespace(character) || character == '>' || + character == '+' || character == '~' || character == ',' || + character == '[' || character == ']'; +} + +static int parse_css_selector(lua_State *lua, const char *source, + size_t length, CssSelector *selector) { + size_t index = 0; + + memset(selector, 0, sizeof(*selector)); + if (length == 0) { + return luaL_argerror(lua, 2, "selector cannot be empty"); + } + + if (source[0] == '*') { + index = 1; + } else if (!is_selector_delimiter(source[0])) { + selector->tag = source; + while (index < length && !is_selector_delimiter(source[index])) { + if (is_unsupported_selector_character(source[index])) { + return luaL_argerror(lua, 2, "unsupported CSS selector"); + } + ++index; + } + selector->tag_length = index; + } + + selector->suffixes = source + index; + selector->suffixes_length = length - index; + while (index < length) { + char delimiter = source[index++]; + size_t start = index; + + if (!is_selector_delimiter(delimiter)) { + return luaL_argerror(lua, 2, "unsupported CSS selector"); + } + while (index < length && !is_selector_delimiter(source[index])) { + if (is_unsupported_selector_character(source[index])) { + return luaL_argerror(lua, 2, "unsupported CSS selector"); + } + ++index; + } + if (index == start) { + return luaL_argerror(lua, 2, "invalid CSS selector"); + } + if (delimiter == '#') { + if (selector->id != NULL) { + return luaL_argerror(lua, 2, "selector can contain only one id"); + } + selector->id = source + start; + selector->id_length = index - start; + } + } + return 0; +} + +static int string_field_equals(lua_State *lua, int table_index, + const char *field, const char *wanted, + size_t wanted_length, int ignore_case) { + const char *value; + size_t value_length; + int matches = 0; + + table_index = absolute_index(lua, table_index); + lua_getfield(lua, table_index, field); + if (lua_type(lua, -1) == LUA_TSTRING) { + value = lua_tolstring(lua, -1, &value_length); + if (value_length == wanted_length) { + matches = ignore_case ? strncasecmp(value, wanted, wanted_length) == 0 + : memcmp(value, wanted, wanted_length) == 0; + } + } + lua_pop(lua, 1); + return matches; +} + +static int node_matches_selector(lua_State *lua, int node_index, + const CssSelector *selector) { + size_t index = 0; + int attributes_index; + + node_index = absolute_index(lua, node_index); + lua_getfield(lua, node_index, "tag"); + if (lua_type(lua, -1) != LUA_TSTRING) { + lua_pop(lua, 1); + return 0; + } + lua_pop(lua, 1); + if (selector->tag != NULL && + !string_field_equals(lua, node_index, "tag", selector->tag, + selector->tag_length, 1)) { + return 0; + } + + lua_getfield(lua, node_index, "attributes"); + if (!lua_istable(lua, -1)) { + lua_pop(lua, 1); + return selector->suffixes_length == 0; + } + attributes_index = lua_gettop(lua); + + while (index < selector->suffixes_length) { + char delimiter = selector->suffixes[index++]; + size_t start = index; + int matches; + + while (index < selector->suffixes_length && + !is_selector_delimiter(selector->suffixes[index])) { + ++index; + } + if (delimiter == '.') { + matches = node_has_class(lua, node_index, selector->suffixes + start, + index - start); + } else { + matches = string_field_equals(lua, attributes_index, "id", + selector->suffixes + start, index - start, + 0); + } + if (!matches) { + lua_pop(lua, 1); + return 0; + } + } + + lua_pop(lua, 1); + return 1; +} + +static void append_matches_by_selector(lua_State *lua, int node_index, + const CssSelector *selector, + int matches_index, + size_t *match_count) { size_t child_count; size_t index; if (!lua_checkstack(lua, 3)) { - return luaL_error(lua, "HTML tree is too deep to search"); + luaL_error(lua, "HTML tree is too deep to search"); } node_index = absolute_index(lua, node_index); - if (node_has_class(lua, node_index, wanted, wanted_length)) { + matches_index = absolute_index(lua, matches_index); + if (node_matches_selector(lua, node_index, selector)) { + if (*match_count == INT_MAX) { + luaL_error(lua, "HTML query has too many matches"); + } + ++*match_count; lua_pushvalue(lua, node_index); - return 1; + lua_rawseti(lua, matches_index, (int)*match_count); } lua_getfield(lua, node_index, "children"); if (!lua_istable(lua, -1)) { lua_pop(lua, 1); - return 0; + return; } child_count = lua_objlen(lua, -1); if (child_count > INT_MAX) { - return luaL_error(lua, "HTML node has too many children to search"); + luaL_error(lua, "HTML node has too many children to search"); } for (index = 1; index <= child_count; ++index) { lua_rawgeti(lua, -1, (int)index); - if (lua_istable(lua, -1) && - push_first_by_class(lua, -1, wanted, wanted_length)) { - lua_remove(lua, -2); - lua_remove(lua, -2); - return 1; + if (lua_istable(lua, -1)) { + append_matches_by_selector(lua, -1, selector, matches_index, + match_count); } lua_pop(lua, 1); } lua_pop(lua, 1); - return 0; } -static int html_find_by_class(lua_State *lua) { +static int query_all(lua_State *lua, const char *source, size_t length) { + CssSelector selector; + size_t match_count = 0; + int matches_index; + + parse_css_selector(lua, source, length, &selector); + lua_newtable(lua); + matches_index = lua_gettop(lua); + append_matches_by_selector(lua, 1, &selector, matches_index, &match_count); + return 1; +} + +static int query(lua_State *lua, const char *source, size_t length) { + query_all(lua, source, length); + lua_rawgeti(lua, -1, 1); + lua_remove(lua, -2); + return 1; +} + +static const char *check_query_arguments(lua_State *lua, size_t *length) { + luaL_checktype(lua, 1, LUA_TTABLE); + luaL_checktype(lua, 2, LUA_TSTRING); + return lua_tolstring(lua, 2, length); +} + +static int html_query(lua_State *lua) { + const char *source; + size_t length; + + source = check_query_arguments(lua, &length); + return query(lua, source, length); +} + +static int html_query_all(lua_State *lua) { + const char *source; + size_t length; + + source = check_query_arguments(lua, &length); + return query_all(lua, source, length); +} + +static int find_by_attribute_token(lua_State *lua, char prefix, + const char *empty_error, + const char *token_error) { const char *wanted; size_t wanted_length; size_t index; + luaL_Buffer selector; luaL_checktype(lua, 1, LUA_TTABLE); luaL_checktype(lua, 2, LUA_TSTRING); wanted = lua_tolstring(lua, 2, &wanted_length); if (wanted_length == 0) { - return luaL_argerror(lua, 2, "class cannot be empty"); + return luaL_argerror(lua, 2, empty_error); } for (index = 0; index < wanted_length; ++index) { - if (is_html_whitespace(wanted[index])) { - return luaL_argerror(lua, 2, "class must be a single token"); + if (is_html_whitespace(wanted[index]) || + is_selector_delimiter(wanted[index]) || + is_unsupported_selector_character(wanted[index])) { + return luaL_argerror(lua, 2, token_error); } } - if (!push_first_by_class(lua, 1, wanted, wanted_length)) { - lua_pushnil(lua); - } - return 1; + luaL_buffinit(lua, &selector); + luaL_addchar(&selector, prefix); + luaL_addlstring(&selector, wanted, wanted_length); + luaL_pushresult(&selector); + wanted = lua_tolstring(lua, -1, &wanted_length); + return query(lua, wanted, wanted_length); +} + +static int html_find_by_class(lua_State *lua) { + return find_by_attribute_token(lua, '.', "class cannot be empty", + "class must be a single token"); +} + +static int html_find_by_id(lua_State *lua) { + return find_by_attribute_token(lua, '#', "id cannot be empty", + "id must be a single token"); } void dom_register_html(lua_State *lua) { @@ -310,6 +514,10 @@ void dom_register_html(lua_State *lua) { lua_newtable(lua); lua_pushcfunction(lua, html_append); lua_setfield(lua, -2, "append"); + lua_pushcfunction(lua, html_query); + lua_setfield(lua, -2, "query"); + lua_pushcfunction(lua, html_query_all); + lua_setfield(lua, -2, "query_all"); lua_setfield(lua, -2, "__index"); lua_pushboolean(lua, 0); lua_setfield(lua, -2, "__metatable"); @@ -323,6 +531,12 @@ void dom_register_html(lua_State *lua) { lua_setfield(lua, -2, "append"); lua_pushcfunction(lua, html_find_by_class); lua_setfield(lua, -2, "find_by_class"); + lua_pushcfunction(lua, html_find_by_id); + lua_setfield(lua, -2, "find_by_id"); + lua_pushcfunction(lua, html_query); + lua_setfield(lua, -2, "query"); + lua_pushcfunction(lua, html_query_all); + lua_setfield(lua, -2, "query_all"); lua_setglobal(lua, "html"); } |