x::http::form::parameters
is a reference to reference-counted object
that represents
parameters for a
submitted form. It is,
essentially, a
std::multimap<std::string, std::string>,
and can be treated as such:
#include <x/http/form.H> x::http::form::parameters params(x::http::form::parameters::create()); params-<insert(std::make_pair("password", "opensesame"));
The form.H header files also defines
x::http::form::parametersptr, a nullable
reference pointer; also
x::http::form::const_parameters and
x::http::form::const_parametersptr, the
constant variations.
The following constructors are available
in addition to the default constructor (forwarded by the
reference create() method) that instantiates an
empty form parameter map:
x::http::form::parameters::create("list", "alpha", "list", "beta", "option", "explicit");
An even-sized string list initializes the contents of the map.
x::http::form::parameters::create("list=alpha&list=beta&option=explicit")
A single string parameter initializes form parameters from an
application/x-www-form-urlencoded-formatted string.
std::vector<char> buf; x::http::form::parameters::create(buf);
A container passed as a parameter initializes form parameters from
the sequence obtained by the container's
begin() and end() methods.
typedef std::istreambuf_iterator<char> iterator; iterator beg_iter, end_iter; // ... x::http::form::parameters params; params->decode_params(x::http::form::limited_iter<iterator>(beg_iter, 8192), x::http::form::limited_iter<iterator>(end_iter));
The form parameter object's decode_params() method
takes a beginning and an ending iterator. It adds additional
parameters to the form that are from the
application/x-www-form-urlencoded-formatted string
that's defined by the beginning and the ending iterator.
x::http::form::limited_iter is a convenient
template class that enforces a maximum limit on the overall size of
the form, in situations where it's not known in advance.
x::http::form::limited_iter's constructor
for a beginning iterator takes the underlying iterator, and a byte
count, then constructs a wrapper that iterates over the
underlying iterator, but throws an exception after the specified number
of bytes, 8192 in the above example.
x::http::form::limited_iter's constructor
for an ending iterator is generally a no-op.
x::http::form::parameters params; x::http::form::parameters::base::encode_iter b=params->begin(), e=params->end(); std::copy(b, e, std::ostreambuf_iterator<char>(std::cout);
The form's begin() and end()
methods define an input sequence that encode the form using
application/x-www-form-urlencoded encoding.