How to pass data along with a ruby block? - ruby

Question

I'm trying to pass some data as a block to some external API. It would be a hassle to accommodate it to accepting additional parameters. If it were javascript, I might make it like so:
var callback = function() {
// do something
}
callback['__someData'] = options;
someExternalAPI(callback);
Is this possible with Ruby? Or how should I go about associating some data with a block?
Not sure if the edits to the question were correct. First, I'd like to specifically pass some data along with a block if that is possible. Not sure if it is though. And probably the only way to do it in ruby is to pass some data as a block.
Additionally, here might be some useful info.
Okay, it probably makes sense to show the whole picture. I'm trying to adapt webmock to my needs. I have a function, which checks if request's params (be them of POST, or of GET) match specified criteria:
def check_params params, options
options.all? do |k,v|
return true unless k.is_a? String
case v
when Hash
return false unless params[k]
int_methods = ['<', '<=', '>', '>=']
v1 = int_methods.include?(v.first[0]) ? params[k].to_i : params[k]
v2 = int_methods.include?(v.first[0]) \
? v.first[1].to_i : v.first[1].to_s
v1.send(v.first[0], v2)
when TrueClass, FalseClass
v ^ ! params.key?(k)
else
params[k] == v.to_s
end
end
end
It's not perfect, but it suffices for my particular needs, for now. I'm calling it like this:
stub_request(:post, 'http://example.com/')
.with { |request|
check_params Rack::Utils.parse_query(request.body), options
}
And the thing is generally I see no sensible way to output with block conditions. But in my particular case one can just output options hash. And instead of this:
registered request stubs:
stub_request(:post, "http://example.com")
to have this:
stub_request(:post, "http://example.com").
with(block: {"year"=>2015})
Which is what I'm trying to do.

Answer 1

Okay, I ended up doing this:
p = Proc.new {}
p.class.module_eval { attr_accessor :__options }
p.__options = {a: 1}
# ...
pp p.__options
Or to be more specific:
def mk_block_cond options, &block_cond
options = options.select { |k,v| ! k.is_a?(Symbol) }
return block_cond if options.empty?
block_cond.class.module_eval { attr_accessor :__options }
block_cond.__options = options
block_cond
end
module WebMock
class RequestPattern
attr_reader :with_block
end
end
module StubRequestSnippetExtensions
def to_s(with_response = true)
request_pattern = #request_stub.request_pattern
string = "stub_request(:#{request_pattern.method_pattern.to_s},"
string << " \"#{request_pattern.uri_pattern.to_s}\")"
with = ""
if (request_pattern.body_pattern)
with << ":body => #{request_pattern.body_pattern.to_s}"
end
if (request_pattern.headers_pattern)
with << ",\n " unless with.empty?
with << ":headers => #{request_pattern.headers_pattern.to_s}"
end
if request_pattern.with_block \
&& request_pattern.with_block.respond_to?('__options') \
&& request_pattern.with_block.__options
with << ",\n " unless with.empty?
with << "block: #{request_pattern.with_block.__options}"
end
string << ".\n with(#{with})" unless with.empty?
if with_response
string << ".\n to_return(:status => 200, :body => \"\", :headers => {})"
end
string
end
end
module WebMock
class StubRequestSnippet
prepend StubRequestSnippetExtensions
end
end
module RequestPatternExtensions
def to_s
string = "#{#method_pattern.to_s.upcase}"
string << " #{#uri_pattern.to_s}"
string << " with body #{#body_pattern.to_s}" if #body_pattern
string << " with headers #{#headers_pattern.to_s}" if #headers_pattern
if #with_block
if #with_block.respond_to?('__options') \
&& #with_block.__options
string << " with block: %s" % #with_block.__options.inspect
else
string << " with given block"
end
end
string
end
end
module WebMock
class RequestPattern
prepend RequestPatternExtensions
end
end
And now I stub requests this way:
stub_request(:post, 'http://example.com/')
.with &mk_block_cond(options) { |request|
check_params Rack::Utils.parse_query(request.body), options
}
P.S. github issue