URL encode in Erlang

AFAIK there’s no URL encoder in the standard libraries exclude edoc_lib:escape_uri. Think I ‘borrowed’ the following code from YAWS or maybe one of the other Erlang web servers


% Utility function to convert a 'form' of name-value pairs into a URL encoded
% content string.

urlencode(Form) ->
    RevPairs = lists:foldl(fun({K,V},Acc) -> [[quote_plus(K),$=,quote_plus(V)] | Acc] end, [],Form),
    lists:flatten(revjoin(RevPairs,$&,[])).

quote_plus(Atom) when is_atom(Atom) ->
    quote_plus(atom_to_list(Atom));

quote_plus(Int) when is_integer(Int) ->
    quote_plus(integer_to_list(Int));

quote_plus(String) ->
    quote_plus(String, []).

quote_plus([], Acc) ->
    lists:reverse(Acc);

quote_plus([C | Rest], Acc) when ?QS_SAFE(C) ->
    quote_plus(Rest, [C | Acc]);

quote_plus([$\s | Rest], Acc) ->
    quote_plus(Rest, [$+ | Acc]);

quote_plus([C | Rest], Acc) ->
    <> = <>,
    quote_plus(Rest, [hexdigit(Lo), hexdigit(Hi), ?PERCENT | Acc]).

revjoin([], _Separator, Acc) ->
    Acc;

revjoin([S | Rest],Separator,[]) ->

Here’s a “fork” of the edoc_lib:escape_uri function that improves on the UTF-8 support and also supports binaries


escape_uri(S) when is_list(S) ->
    escape_uri(unicode:characters_to_binary(S));
escape_uri(<>) when C >= $a, C =< $z ->
    [C] ++ escape_uri(Cs);
escape_uri(<>) when C >= $A, C =< $Z ->
    [C] ++ escape_uri(Cs);
escape_uri(<>) when C >= $0, C =< $9 ->
    [C] ++ escape_uri(Cs);
escape_uri(<>) when C == $. ->
    [C] ++ escape_uri(Cs);
escape_uri(<>) when C == $- ->
    [C] ++ escape_uri(Cs);
escape_uri(<>) when C == $_ ->
    [C] ++ escape_uri(Cs);
escape_uri(<>) ->
    escape_byte(C) ++ escape_uri(Cs);
escape_uri(<<>>) ->
    "".

escape_byte(C) ->
    "%" ++ hex_octet(C).

hex_octet(N) when N =< 9 ->
    [$0 + N];
hex_octet(N) when N > 15 ->
    hex_octet(N bsr 4) ++ hex_octet(N band 15);
hex_octet(N) ->
    [N - 10 + $a].

Читайте також:

coded by nessus