I'm trying to create a nice interface for making HTTP calls in my game engine via Python, I have run into a bit of a problem, however.
I have a single function, get_async which launches a curl request for the specified URL. The function is defined inside an http_manager class, like so:
struct http_manager
{
typedef function<void(boost::shared_ptr<http_response>)> response_callback_type;
typedef function<void(size_t)> write_callback_type;
void get_async(
const string& url,
const http_headers_type& headers = http_headers_type(),
const http_data_type& data = http_data_type(),
response_callback_type on_response = nullptr,
write_callback_type on_write = nullptr
);
};
I am able to successfully make this call in Python:
http.get_async('http://www.google.ca')
However, I want to make a call like this:
http.get_async('http://www.google.ca', on_response=f)
The key here is that I want to explicitly specify the arguments by name and let all the others be the defaults, just like in regular Python.
Unfortunately, when I do this, I get the following error back from Python:
ArgumentError: Python argument types in
HttpManager.get_async(HttpManager, str)
did not match C++ signature:
get_async(struct naga::http_manager {lvalue}, class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > url)
get_async(struct naga::http_manager {lvalue}, class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > url, class std::vector<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > headers)
get_async(struct naga::http_manager {lvalue}, class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > url, class std::vector<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > headers, class std::map<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > data)
get_async(struct naga::http_manager {lvalue}, class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > url, class std::vector<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > headers, class std::map<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > data, class std::function<void __cdecl(class boost::shared_ptr<struct naga::http_response>)> on_response)
get_async(struct naga::http_manager {lvalue}, class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > url, class std::vector<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > headers, class std::map<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > data, class std::function<void __cdecl(class boost::shared_ptr<struct naga::http_response>)> on_response, class std::function<void __cdecl(unsigned int)> on_write)
I'm confused as to why it thinks that the argument signature is HttpManager.get_async(HttpManager, str) when I'm clearly passing 3 arguments (self, url and on_response).
Here are the relevant bits from my BOOST_PYTHON_MODULE block:
BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS(http_manager_get_async_overloads, http_manager::get_async, 1, 5)
class_<http_manager, noncopyable>("HttpManager", no_init)
.def("get_async", &http_manager::get_async, http_manager_get_async_overloads(args("url", "headers", "data", "on_response", "on_write")))
;
Thank you for reading and any help is greatly appreciated!