def main(self, signature=""):
"""
A decorator that is used to register the main function with the given
`signature`::
@app.main()
def main(context):
# do something
pass
The main function is called, after any options and if no command has
been called.
"""
signature = Signature.from_string(signature, option=False)
def decorator(function):
if self.main_func is not None:
raise RuntimeError("main is already defined")
self.main_func = function
self.main_signature = signature
if function.__doc__:
self.description = textwrap.dedent(function.__doc__).strip()
return function
return decorator
def from_string(cls, string, function, overrideable=False):
parts = string.split(" ", 1)
if not parts or not parts[0]:
raise InvalidSignature("option name missing")
names = parts[0]
if u"|" in names:
names = names.split(u"|")
else:
names = [names]
for name in names:
if name.startswith("--"):
if len(name) == 2:
raise InvalidSignature("option with long prefix is missing a name")
elif name.startswith("-"):
if len(name) == 1:
raise InvalidSignature("option with short prefix is missing a name")
elif len(name) > 2:
raise InvalidSignature("short option with name longer than one character: %s" % name)
if parts[1:]:
signature = Signature.from_string(parts[1])
else:
signature = Signature([])
return cls(names, function, signature, overrideable=overrideable)
