Function handler in general and json function in particular are the
easiest way to add logic to to handler.
While in some cases the method can return immediately, there are cases
when it is required to perform an async operation, to support those
cases, the function handler was modified to use future.
If it receives an old style function, it would wrap the results in a
make_ready_future. This you could still assign a function like:
new function_handler([](const_req req) {
return "hello";
});
It would no also support a function that return a future json so it is
no possible to assign logic like:
new function_handler([](std::unique_ptr<request> req) {
return make_ready_future<json::json_return_type>("json-future");
});
For the future case note that auto-boxing still works, although you now
need to use make_ready_future.
The json_path was also modified to accept the new kind of function, to
support the common case of route definition based on the code
generation.
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
This demonstrate how to use a swagger definition file to create an API.
The swagger file demo.json define one api called hello_world, it has
both query and path parameters and return an object as a result.
The handler implementation simply places the given parameters in the
return object.
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
File handlers support reading local file and return it as the result
for the http request.
There are two kind of handler, a file handler will return a specific
file when called. A directory handler expect to find a path parameter
called 'path' and would concatinate this parameter to the direcoty path.
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Most of the time, implementing an http handler consist of a small amount
of logic.
Function handlers are a simplified way of adding such a logic, they
accept a lambda expression of various types and eliminate the need to
create a type for the handlers.
The prefered way of creating a handler is by using the
json_request_function, it would use auto-boxing to return a json object.
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
The http server handlers can sometimes need to perform async operation,
specifically, when reading files from the disk. To support async
behavior the handlers handle function will return a future, that will be
propagate back, when the future will be ready it will return the reply
to be sent.
When switching from direct function call to future, there is also a need
to switch from references to pointers.
Note that while the request will be discarded, the reply will be
propagate back via the future to the caller.
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
This use the routes and the reqeuest found in the http directory and
move all files but main to the http directory
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
We would like to extend the httpd capabilities and use it for the API
implementation.
The first step is to make it a library with main that calls an instanse.
This break the implementation to a header file, implementation and main,
that simply calls the implementation.
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>