request.py 文件源码

def handle(mapping, fvars=None):
    """
    Call the appropriate function based on the url to function mapping in `mapping`.
    If no module for the function is specified, look up the function in `fvars`. If
    `fvars` is empty, using the caller's context.

    `mapping` should be a tuple of paired regular expressions with function name
    substitutions. `handle` will import modules as necessary.
    """
    for url, ofno in utils.group(mapping, 2):
        if isinstance(ofno, tuple): 
            ofn, fna = ofno[0], list(ofno[1:])
        else: 
            ofn, fna = ofno, []
        fn, result = utils.re_subm('^' + url + '$', ofn, web.ctx.path)
        if result: # it's a match
            if fn.split(' ', 1)[0] == "redirect":
                url = fn.split(' ', 1)[1]
                if web.ctx.method == "GET":
                    x = web.ctx.env.get('QUERY_STRING', '')
                    if x: 
                        url += '?' + x
                return http.redirect(url)
            elif '.' in fn: 
                x = fn.split('.')
                mod, cls = '.'.join(x[:-1]), x[-1]
                mod = __import__(mod, globals(), locals(), [""])
                cls = getattr(mod, cls)
            else:
                cls = fn
                mod = fvars
                if isinstance(mod, types.ModuleType): 
                    mod = vars(mod)
                try: 
                    cls = mod[cls]
                except KeyError: 
                    return web.notfound()

            meth = web.ctx.method
            if meth == "HEAD":
                if not hasattr(cls, meth): 
                    meth = "GET"
            if not hasattr(cls, meth): 
                return nomethod(cls)
            tocall = getattr(cls(), meth)
            args = list(result.groups())
            for d in re.findall(r'\\(\d+)', ofn):
                args.pop(int(d) - 1)
            return tocall(*([x and urllib.unquote(x) for x in args] + fna))

    return web.notfound()