BaseHTTPRequestHandler with custom instance

Question

this is my http server:

from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer

class test:
    def show(self):
        return "aaaa"

class http_server:
    def __init__(self, t1):
        self.t1 = t1
        server = HTTPServer(('', 8080), myHandler)
        server.serve_forever()

class myHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        self.send_response(200)
        self.send_header('Content-type','text/html')
        self.end_headers()
        self.wfile.write(self.t1.show()) #Doesnt work
        return

class main:
    def __init__(self):
        self.t1 = test()
        self.server = http_server(self.t1)

if __name__ == '__main__':
    m = main()

I need to acces instance t1 inside of myHander.

Is there any way how to do it ?

Thanks!

Answer 1

there a way to do it is to set the property to the class :

from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer

class test:
    def show(self):
        return "aaaa"

class http_server:
    def __init__(self, t1):
        myHandler.t1 = t1
        server = HTTPServer(('', 8080), myHandler)
        server.serve_forever()

class myHandler(BaseHTTPRequestHandler):
    t1 = None
    def do_GET(self):
        self.send_response(200)
        self.send_header('Content-type','text/html')
        self.end_headers()
        self.wfile.write(self.t1.show()) #Doesnt work
        return

class main:
    def __init__(self):
        self.t1 = test()

        self.server = http_server(self.t1)

if __name__ == '__main__':
    m = main()

You have to be careful that's every where you use myHandler that's will be the same instance of t1

Answer 2

Another flavor of answer to this 8-year-old question :) I too wanted to avoid using class variables that share across all Handler objects just in case, but it took me a minute to understand why @rsmoorthy's answer worked. This is basically the same answer as his, but using functools.partial to add clarity.

As HTTPServer expects the handler as a RequestHandlerClass, we can't fully instantiate the class. But we can give our subclass a custom __init__ that accepts additional data, then use functools.partial to fill that extra info in for HTTPServer. This way it just instantiates our handler like it wants to, but we still get t1 passed inside.

from http.server import BaseHTTPRequestHandler, HTTPServer
import functools


class test:
    def show(self):
        return b"aaaa"

class http_server:
    def __init__(self, t1):
        handler_partial = functools.partial(Handler, t1=t1)
        server = HTTPServer(('', 8080), handler_partial)
        server.serve_forever()

class Handler(BaseHTTPRequestHandler):
    def __init__(self, *args, t1=None, **kwargs):
        # Assign before super().__init__ because init is what triggers parsing the request
        self.t1 = t1
        super().__init__(*args, **kwargs)

    def do_GET(self):
        self.send_response(200)
        self.send_header('Content-type','text/html')
        self.end_headers()
        self.wfile.write(self.t1.show())
        return

class main:
    def __init__(self):
        self.t1 = test()
        self.server = http_server(self.t1)

if __name__ == '__main__':
    m = main()

Answer 3

Aaaand another answer to this old question, this time using a factory function that creates subclasses of BaseHTTPRequestHandler with our t1 already available.

from http.server import BaseHTTPRequestHandler, HTTPServer

class test:
    def show(self):
        return b"aaaa"

class http_server:
    def __init__(self, t1):
        myHandler = handlerFactory(t1)
        server = HTTPServer(('', 8080), myHandler)
        server.serve_forever()

def handlerFactory(t1):
    class myHandler(BaseHTTPRequestHandler):
        def do_GET(self):
            self.send_response(200)
            self.send_header('Content-type','text/html')
            self.end_headers()
            self.wfile.write(t1.show())
            return
    return myHandler

class main:
    def __init__(self):
        self.t1 = test()
        self.server = http_server(self.t1)

if __name__ == '__main__':
    m = main()

Answer 4

Slightly better version, where t1 will not be the same for each instance.

from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer

class test:
    def show(self):
        return "aaaa"

class http_server:
    def __init__(self, t1):
        def handler(*args):
            myHandler(t1, *args)
        server = HTTPServer(('', 8080), handler)
        server.serve_forever()

class myHandler(BaseHTTPRequestHandler):
    def __init__(self, t1, *args):
        self.t1 = t1
        BaseHTTPRequestHandler.__init__(self, *args)

    def do_GET(self):
        self.send_response(200)
        self.send_header('Content-type','text/html')
        self.end_headers()
        self.wfile.write(self.t1.show()) #Doesnt work
        return

class main:
    def __init__(self):
        self.t1 = test()

        self.server = http_server(self.t1)

if __name__ == '__main__':
    m = main()

Answer 5

Encountered the same issue and was trying to follow @XaF's answer; cannot comment due to low cool point value, so adding an answer below.

In my case I have the HTTPServer as a 'private' member of the server class, and did not realize that Python would handle 'private' member such that the corresponding member accessed in the server instance of the handler is actually prepended with name of the server class, which in OP's example would be self.server._http_server__t1. So use self.server._<server class name>__<private member name> instead of self.server.<member name>.

Answer 6

I know I'm answering pretty late, but that could probably be helpful for future viewers. There is a really easy way to access t1 like it was asked by using the server variable of the BaseHTTPRequestHandler object:

from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer

class test:
    def show(self):
        return "aaaa"

class http_server:
    def __init__(self, t1):
        server = HTTPServer(('', 8080), myHandler)
        server.t1 = t1
        server.serve_forever()

class myHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        self.send_response(200)
        self.send_header('Content-type','text/html')
        self.end_headers()
        self.wfile.write(self.server.t1.show())
        return

class main:
    def __init__(self):
        self.t1 = test()
        self.server = http_server(self.t1)

if __name__ == '__main__':
    m = main()