Add configuration to allow overriding the encoding method.

[FabienChaynes]

This PR is related to #22.
It is obviously missing some specs and documentation, which I will add once we'll agree on the implementation.

It adds a Configuration object with an @encoding_method variable.

This variable will receive a Proc and will default to the ::URI.encode_www_form method. If the variable is set, the Proc should expect a single argument responding to #to_h and return a string of the encoded hash.
It'd allow users to override the method encoding data in HTTP::FormData::Urlencoded#initialize.

An example of the usage could be:

HTTP::FormData.configure do |config|
  custom_encode_www_form = lambda do |enum|
    unescaped_chars = /[^a-z0-9\-\.\_\~]/i
    enum.map do |k, v|
      if v.nil?
        ::URI::DEFAULT_PARSER.escape(k.to_s, unescaped_chars)
      elsif v.respond_to?(:to_ary)
        v.to_ary.map do |w|
          str = ::URI::DEFAULT_PARSER.escape(k.to_s, unescaped_chars)
          unless w.nil?
            str << '='
            str << ::URI::DEFAULT_PARSER.escape(w.to_s, unescaped_chars)
          end
        end.join('&')
      else
        str = ::URI::DEFAULT_PARSER.escape(k.to_s, unescaped_chars)
        str << '='
        str << ::URI::DEFAULT_PARSER.escape(v.to_s, unescaped_chars)
      end
    end.join('&')
  end

  config.encoding_method = custom_encode_www_form
end

[ixti]

I don't like the idea of configuration object - it's overkill in here IMO. Also, I think there should be a way to pass encoder to Urlencoded initializer.

[FabienChaynes]

I removed the configuration in the first commit and allowed Urlencoded to receive the encoder at initialization in the second one.
Now it will allow a simpler monkey patching along the lines of:

require "uri"

module HTTP
  module FormData
    def self.encoder
      lambda do |enum|
        unescaped_chars = /[^a-z0-9\-\.\_\~]/i
        enum.map do |k, v|
          if v.nil?
            ::URI::DEFAULT_PARSER.escape(k.to_s, unescaped_chars)
          elsif v.respond_to?(:to_ary)
            v.to_ary.map do |w|
              str = ::URI::DEFAULT_PARSER.escape(k.to_s, unescaped_chars)
              unless w.nil?
                str << '='
                str << ::URI::DEFAULT_PARSER.escape(w.to_s, unescaped_chars)
              end
            end.join('&')
          else
            str = ::URI::DEFAULT_PARSER.escape(k.to_s, unescaped_chars)
            str << '='
            str << ::URI::DEFAULT_PARSER.escape(v.to_s, unescaped_chars)
          end
        end.join('&')
      end
    end
  end
end

I'm not a huge fan of this solution though 😕
Do you have something else in mind to customize this without a configuration object?

[FabienChaynes]

Re reading your comment, maybe you were just talking about exposing the encoder without wrapping it inside a Configuration object (which I did in d7a2c3f).
This way it'd be used like this:

HTTP::FormData.encoder = lambda do |enum|
  # ...
end

[ixti]

I have changed this code a bit and merged this PR as 3bf2e83

So basically I have moved away from the idea of having per-form encoder (at least for now). And exposed encoder on Urlencoded class. Meaning one can override default implementation with:

HTTP::FormData::Urlencoded.encoder = lambda { |data| ... }

[ixti]

Thank you!

[FabienChaynes]

Great, thanks!

[ixti]

Released as v2.1.1