From 1bb2c76c09510bf761c4a6908ae78d1e2a87d574 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C3=A9ter=20Dimitrov?= Date: Tue, 7 Nov 2017 16:23:09 +0100 Subject: stdlib: Implement compose and dissect query (HTML5) Implement functions for handling form-urlencoded query strings based on the HTML5 specification. --- lib/stdlib/src/uri_string.erl | 229 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 228 insertions(+), 1 deletion(-) (limited to 'lib/stdlib/src') diff --git a/lib/stdlib/src/uri_string.erl b/lib/stdlib/src/uri_string.erl index 22212da222..a84679c595 100644 --- a/lib/stdlib/src/uri_string.erl +++ b/lib/stdlib/src/uri_string.erl @@ -226,7 +226,8 @@ %%------------------------------------------------------------------------- %% External API %%------------------------------------------------------------------------- --export([normalize/1, parse/1, +-export([compose_query/1, compose_query/2, + dissect_query/1, normalize/1, parse/1, recompose/1, transcode/2]). -export_type([error/0, uri_map/0, uri_string/0]). @@ -381,6 +382,76 @@ transcode(URIString, Options) when is_list(URIString) -> end. +%%------------------------------------------------------------------------- +%% Functions for working with the query part of a URI as a list +%% of key/value pairs. +%% HTML5 - 4.10.22.6 URL-encoded form data +%%------------------------------------------------------------------------- + +%%------------------------------------------------------------------------- +%% Compose urlencoded query string from a list of unescaped key/value pairs. +%% (application/x-www-form-urlencoded encoding algorithm) +%%------------------------------------------------------------------------- +-spec compose_query(QueryList) -> QueryString when + QueryList :: [{uri_string(), uri_string()}], + QueryString :: uri_string() + | error(). +compose_query(List) -> + compose_query(List, [{encoding, utf8}]). + + +-spec compose_query(QueryList, Options) -> QueryString when + QueryList :: [{uri_string(), uri_string()}], + Options :: [{encoding, atom()}], + QueryString :: uri_string() + | error(). +compose_query([],_Options) -> + []; +compose_query(List, Options) -> + try compose_query(List, Options, false, <<>>) + catch + throw:{error, Atom, RestData} -> {error, Atom, RestData} + end. +%% +compose_query([{Key,Value}|Rest], Options, IsList, Acc) -> + Separator = get_separator(Rest), + K = form_urlencode(Key, Options), + V = form_urlencode(Value, Options), + IsListNew = IsList orelse is_list(Key) orelse is_list(Value), + compose_query(Rest, Options, IsListNew, <>. + + +%% HTML5 - 4.10.22.6 URL-encoded form data - encoding +form_urlencode(Cs, [{encoding, latin1}]) when is_list(Cs) -> + B = convert_to_binary(Cs, utf8, utf8), + html5_byte_encode(base10_encode(B)); +form_urlencode(Cs, [{encoding, latin1}]) when is_binary(Cs) -> + html5_byte_encode(base10_encode(Cs)); +form_urlencode(Cs, [{encoding, Encoding}]) + when is_list(Cs), Encoding =:= utf8; Encoding =:= unicode -> + B = convert_to_binary(Cs, utf8, Encoding), + html5_byte_encode(B); +form_urlencode(Cs, [{encoding, Encoding}]) + when is_binary(Cs), Encoding =:= utf8; Encoding =:= unicode -> + html5_byte_encode(Cs); +form_urlencode(Cs, [{encoding, Encoding}]) when is_list(Cs); is_binary(Cs) -> + throw({error,invalid_encoding, Encoding}); +form_urlencode(Cs, _) -> + throw({error,invalid_input, Cs}). + + +%% For each character in the entry's name and value that cannot be expressed using +%% the selected character encoding, replace the character by a string consisting of +%% a U+0026 AMPERSAND character (&), a "#" (U+0023) character, one or more ASCII +%% digits representing the Unicode code point of the character in base ten, and +%% finally a ";" (U+003B) character. +base10_encode(Cs) -> + base10_encode(Cs, <<>>). +%% +base10_encode(<<>>, Acc) -> + Acc; +base10_encode(<>, Acc) when H > 255 -> + Base10 = convert_to_binary(integer_to_list(H,10), utf8, utf8), + base10_encode(T, <>); +base10_encode(<>, Acc) -> + base10_encode(T, <>). + + +html5_byte_encode(B) -> + html5_byte_encode(B, <<>>). +%% +html5_byte_encode(<<>>, Acc) -> + Acc; +html5_byte_encode(<<$ ,T/binary>>, Acc) -> + html5_byte_encode(T, <>); +html5_byte_encode(<>, Acc) -> + case is_url_char(H) of + true -> + html5_byte_encode(T, <>); + false -> + <> = <>, + html5_byte_encode(T, <>) + end; +html5_byte_encode(H, _Acc) -> + throw({error,invalid_input, H}). + + +%% Return true if input char can appear in form-urlencoded string +%% Allowed chararacters: +%% 0x2A, 0x2D, 0x2E, 0x30 to 0x39, 0x41 to 0x5A, +%% 0x5F, 0x61 to 0x7A +is_url_char(C) + when C =:= 16#2A; C =:= 16#2D; + C =:= 16#2E; C =:= 16#5F; + 16#30 =< C, C =< 16#39; + 16#41 =< C, C =< 16#5A; + 16#61 =< C, C =< 16#7A -> true; +is_url_char(_) -> false. + + +%%------------------------------------------------------------------------- +%% Helper functions for dissect_query +%%------------------------------------------------------------------------- +dissect_query_key(<<$=,T/binary>>, IsList, Acc, Key, Value) -> + dissect_query_value(T, IsList, Acc, Key, Value); +dissect_query_key(<<"&#",T/binary>>, IsList, Acc, Key, Value) -> + dissect_query_key(T, IsList, Acc, <>, Value); +dissect_query_key(<<$&,_T/binary>>, _IsList, _Acc, _Key, _Value) -> + throw({error, missing_value, "&"}); +dissect_query_key(<>, IsList, Acc, Key, Value) -> + dissect_query_key(T, IsList, Acc, <>, Value); +dissect_query_key(B, _, _, _, _) -> + throw({error, missing_value, B}). + + +dissect_query_value(<<$&,T/binary>>, IsList, Acc, Key, Value) -> + K = form_urldecode(IsList, Key), + V = form_urldecode(IsList, Value), + dissect_query_key(T, IsList, [{K,V}|Acc], <<>>, <<>>); +dissect_query_value(<>, IsList, Acc, Key, Value) -> + dissect_query_value(T, IsList, Acc, Key, <>); +dissect_query_value(<<>>, IsList, Acc, Key, Value) -> + K = form_urldecode(IsList, Key), + V = form_urldecode(IsList, Value), + lists:reverse([{K,V}|Acc]). + + +%% Form-urldecode input based on RFC 1866 [8.2.1] +form_urldecode(true, B) -> + Result = base10_decode(form_urldecode(B, <<>>)), + convert_to_list(Result, utf8); +form_urldecode(false, B) -> + base10_decode(form_urldecode(B, <<>>)); +form_urldecode(<<>>, Acc) -> + Acc; +form_urldecode(<<$+,T/binary>>, Acc) -> + form_urldecode(T, <>); +form_urldecode(<<$%,C0,C1,T/binary>>, Acc) -> + case is_hex_digit(C0) andalso is_hex_digit(C1) of + true -> + V = ?HEX2DEC(C0)*16+?HEX2DEC(C1), + form_urldecode(T, <>); + false -> + L = convert_to_list(<<$%,C0,C1,T/binary>>, utf8), + throw({error, invalid_percent_encoding, L}) + end; +form_urldecode(<>, Acc) -> + form_urldecode(T, <>); +form_urldecode(<>, _Acc) -> + throw({error, invalid_character, [H]}). + +base10_decode(Cs) -> + base10_decode(Cs, <<>>). +% +base10_decode(<<>>, Acc) -> + Acc; +base10_decode(<<"&#",T/binary>>, Acc) -> + base10_decode_unicode(T, Acc); +base10_decode(<>, Acc) -> + base10_decode(T,<>); +base10_decode(<>, _) -> + throw({error, invalid_input, [H]}). + + +base10_decode_unicode(B, Acc) -> + base10_decode_unicode(B, 0, Acc). +%% +base10_decode_unicode(<>, Codepoint, Acc) when $0 =< H, H =< $9 -> + Res = Codepoint * 10 + (H - $0), + base10_decode_unicode(T, Res, Acc); +base10_decode_unicode(<<$;,T/binary>>, Codepoint, Acc) -> + base10_decode(T, <>); +base10_decode_unicode(<>, _, _) -> + throw({error, invalid_input, [H]}). + + %%------------------------------------------------------------------------- %% Helper functions for normalize %%------------------------------------------------------------------------- -- cgit v1.2.3