Refactor yield-mechanism to be present on top of the module, removing dependence on utils.delay and optimizing some imports.

evennia/commands/cmdhandler.py

@@ -39,6 +39,8 @@ from traceback import format_exc
 from itertools import chain
 from copy import copy
 import types
+from twisted.internet import reactor
+from twisted.internet.task import deferLater
 from twisted.internet.defer import inlineCallbacks, returnValue
 from django.conf import settings
 from evennia.comms.channelhandler import CHANNELHANDLER
@@ -128,6 +130,12 @@ _ERROR_RECURSION_LIMIT = "Command recursion limit ({recursion_limit}) " \
                          "reached for '{raw_string}' ({cmdclass})."
 
 
+# delayed imports
+_GET_INPUT = None
+
+
+# helper functions
+
 def _msg_err(receiver, stringtuple):
     """
     Helper function for returning an error to the caller.
@@ -152,12 +160,77 @@ def _msg_err(receiver, stringtuple):
                                    errmsg=stringtuple[1].strip(),
                                    timestamp=timestamp).strip())
 
+
+def _progressive_cmd_run(cmd, generator, response=None):
+    """
+    Progressively call the command that was given in argument. Used
+    when `yield` is present in the Command's `func()` method.
+
+    Args:
+        cmd (Command): the command itself.
+        generator (GeneratorType): the generator describing the processing.
+        reponse (str, optional): the response to send to the generator.
+
+    Raises:
+        ValueError: If the func call yields something not identifiable as a
+            time-delay or a string prompt.
+
+    Note:
+        This function is responsible for executing the command, if
+        the func() method contains 'yield' instructions.  The yielded
+        value will be accessible at each step and will affect the
+        process.  If the value is a number, just delay the execution
+        of the command.  If it's a string, wait for the user input.
+
+    """
+    global _GET_INPUT
+    if not _GET_INPUT:
+        from evennia.utils.evmenu import get_input as _GET_INPUT
+
+    try:
+        if response is None:
+            value = generator.next()
+        else:
+            value = generator.send(response)
+    except StopIteration:
+        pass
+    else:
+        if isinstance(value, (int, float)):
+            utils.delay(value, _progressive_cmd_run, cmd, generator)
+        elif isinstance(value, basestring):
+            _GET_INPUT(cmd.caller, value, _process_input, cmd=cmd, generator=generator)
+        else:
+            raise ValueError("unknown type for a yielded value in command: {}".format(type(value)))
+
+
+def _process_input(caller, prompt, result, cmd, generator):
+    """
+    Specifically handle the get_input value to send to _progressive_cmd_run as
+    part of yielding from a Command's `func`.
+
+    Args:
+        caller (Character, Player or Session): the caller.
+        prompt (basestring): The sent prompt.
+        result (basestring): The unprocessed answer.
+        cmd (Command): The command itself.
+        generator (GeneratorType): The generator.
+
+    Returns:
+        result (bool): Always `False` (stop processing).
+
+    """
+    # We call it using a Twisted deferLater to make sure the input is properly closed.
+    deferLater(reactor, 0, _progressive_cmd_run, cmd, generator, response=result)
+    return False
+
+
 # custom Exceptions
 
 class NoCmdSets(Exception):
     "No cmdsets found. Critical error."
     pass
 
+
 class ExecSystemCommand(Exception):
     "Run a system command"
     def __init__(self, syscmd, sysarg):
@@ -676,55 +749,3 @@ def cmdhandler(called_by, raw_string, _testing=False, callertype="session", sess
         # This catches exceptions in cmdhandler exceptions themselves
         _msg_err(error_to, _ERROR_CMDHANDLER)
 
-def _progressive_cmd_run(cmd, generator, response=None):
-    """
-    Progressively call the command that was given in argument.
-
-    Args:
-        cmd (Command): the command itself.
-        generator (GeneratorType): the generator describing the processing.
-        reponse (str, optional): the response to send to the generator.
-
-    Note:
-        This function is responsible for executing the command, if
-        the func() method contains 'yield' instructions.  The yielded
-        value will be accessible at each step and will affect the
-        process.  If the value is a number, just delay the execution
-        of the command.  If it's a string, wait for the user input.
-
-    """
-    try:
-        if response is None:
-            value = generator.next()
-        else:
-            value = generator.send(response)
-    except StopIteration:
-        pass
-    else:
-        if isinstance(value, (int, float)):
-            utils.delay(value, _progressive_cmd_run, cmd, generator)
-        elif isinstance(value, basestring):
-            from evennia.utils.evmenu import get_input
-            get_input(cmd.caller, value, _process_input, cmd=cmd, generator=generator)
-        else:
-            raise ValueError("unknown type for a yielded value in command: {}".format(type(value)))
-
-def _process_input(caller, prompt, result, cmd, generator):
-    """
-    Specifically handle the get_input value to send to _progressive_cmd_run.
-
-    Args:
-        caller (Character, Player or Session): the caller.
-        prompt (basestring): the sent prompt.
-        result (basestring): the unprocessed answer.
-        cmd (Command): the command itself.
-        generator (GeneratorType): the generator.
-
-    Returns:
-        Always False (stop processing).
-
-    """
-    # We call it in a 'utils.delay()' to make sure the input is properly closed.
-    utils.delay(0, _progressive_cmd_run, cmd, generator, response=result)
-
-    return False