Cannot post duplicate values (arrays) with agent.post

[jg]

Attempt (doesn't work):

page = agent.post(url, {"array[]"=> ["element1", "element2"]})

The equivalent curl invocation (works):

curl -d url "array[]=element1&array[]=element2"

[sguha00]

What's the correct way to post an array with Mechanize?

[knu]

Mechanize does not currently grok multiple values in an array.

Instead, request methods take an array of pairs as parameters, so you could do as follows:

page = agent.post(url, ["element1", "element2"].map { |v| ["array[]", v] })

If you have other parameters:

page = agent.post(url, [[:x, 1], [:y, 2], *["element1", "element2"].map { |v| ["array[]", v] }])

I'll be working on improving this situation when I get the time.

[knu]

It seems pretty popular to be able to pass a hash also, like array[]=element1&array[]=element2&hash[key1]=value1&hash[key2]=value2, so I'll consider making Mechanize support that too, while making it optional to encode brackets.

[sguha00]

Thanks, the array of pairs way worked for me

[knu]

It seems PHP's http_build_query() is not very compatible with how an array of values assigned to one key is encoded by other well-known implementations of perl, ruby and python.

% php -r 'echo http_build_query(array("foo" => array("x","y"))) . "\n";'
foo%5B0%5D=x&foo%5B1%5D=y
% ruby -ruri -e 'puts URI.encode_www_form("foo" => ["x","y"])'
foo=x&foo=y
% perl -MURI -le '$u = URI->new("http://host/"); $u->query_form(foo => ["x","y"]); print $u->query'
foo=x&foo=y
% python -c 'import urllib; print urllib.urlencode({"foo": ["x","y"]}, True)'
foo=x&foo=y

(And it seems fine to encode brackets)

So, what I have in mind now is:

• { "foo" => ["x","y"] } becomes foo=x&foo=y
• { "foo[]" => ["x","y"] } becomes foo%5B%5D=x&foo%5B%5D=y
• { "foo" => { "x"=>"a", "y"=>"b" } } becomes foo%5Bx%5D=a&foo%5By%5D=b

and maybe

• { "foo" => ["x","y"].each_with_index } becomes foo%5B0%5D=x&foo%5B1%5D=y

[knu]

Closing this as the original problem is solved.
I'll be working on the new feature when I get the time.

[knu]

I've just implemented array/hash value support for query/post parameters.
Check out v2.7.4.beta2 or later.