Add call function to use for deferreds

deferred.py

@@ -1,3 +1,5 @@
+from functools import partial
+
 class Deferred(object):
 	"""
 	Represents a delayed computation. This is a more elegant way to deal with
@@ -8,7 +10,8 @@ class Deferred(object):
 	value by using the then method. Computations dependent on the Deferred will
 	only proceed when the run method is called.
 
-	Attributes of a Deferred can be accessed directly as methods.
+	Attributes of a Deferred can be accessed directly as methods. The result of
+	calling these functions will be Deferred.
 
 	Example:
 		image = Deferred()
@@ -92,6 +95,39 @@ class Then(object):
 			return self.deferred.then(func)
 		return helper
 
+def call(func, *args, **kwargs):
+	"""
+	Call a function with deferred arguments
+
+	Example:
+		colors = Deferred()
+		colors.append('blue')
+		colors.run(['red', 'green'])
+call(print, colors) #=> ['red', 'green', 'blue']
+		call(print, 'hi', colors) #=> hi ['red', 'green', 'blue']
+	"""
+	for i, c in enumerate(args):
+		if isinstance(c, Deferred):
+			# Function without deferred arguments
+			normalfunc = partial(func, *args[:i])
+			# Function with deferred and possibly deferred arguments
+			def restfunc(*arg2, **kwarg2):
+				apply_deferred = partial(normalfunc, *arg2, **kwarg2)
+				return call(apply_deferred, *args[i + 1:], **kwargs)
+			return c.then(restfunc)
+	items = kwargs.items()
+	for i, (k, v) in enumerate(items):
+		if isinstance(v, Deferred):
+			# Function without deferred arguments
+			normalfunc = partial(func, *args, **dict(items[:i]))
+			# Function with deferred and possibly deferred arguments
+			def restfunc2(*arg2, **kwarg2):
+				apply_deferred = partial(normalfunc, *arg2, **kwarg2)
+				return call(apply_deferred, **dict(items[i + 1:]))
+			return c.then(restfunc2)
+	# No items deferred
+	return func(*args, **kwargs)
+
 class DeferredHasValue(Exception):
 	def __init__(self, string):
 		super(DeferredHasValue, self).__init__(string)

session.py

@@ -40,8 +40,8 @@ from threading import Timer
 from group import Group
 from bot import Bot
 import deferred
+from deferred import call
 from yowsupwrapper import YowsupApp
-from functools import partial
 
 
 class MsgIDs:
@@ -736,22 +736,18 @@ class Session(YowsupApp):
 
 		# Send VCard
 		if ID != None:
-			response.pictureId().then(partial(
-				self.logger.debug, 'Sending VCard (%s) with image id %s', ID
-			))
+			call(self.logger.debug, 'Sending VCard (%s) with image id %s',
+					ID, response.pictureId())
 			pictureData = response.pictureData()
-			response.pictureData().then(partial(
-				self.backend.handleVCard, self.user, ID, buddy, "", ""
-			))
+			call(self.backend.handleVCard, self.user, ID, buddy, "", "",
+					response.pictureData())
 
 		# Send image hash
 		if not buddy == self.legacyName:
 			obuddy = self.buddies[buddy]
 			image_hash = pictureData.then(utils.sha1hash)
-			image_hash.then(partial(self.logger.debug, 'Image hash is %s'))
-			image_hash.then(partial(
-				self.updateBuddy, buddy, obuddy.nick, obuddy.groups
-			))
+			call(self.logger.debug, 'Image hash is %s', image_hash)
+			call(self.updateBuddy, buddy, obuddy.nick, obuddy.groups, image_hash)
 
 
 	def onDlsuccess(self, path):