Some changes to telnet console:

* moved module from scrapy.management.telnet to scrapy.telnet (to minimize
  nested modules)
* added signal for updating telnet console variables (fixes #165)

--HG--
rename : scrapy/management/telnet.py => scrapy/telnet.py

docs/topics/telnetconsole.rst

@@ -31,13 +31,13 @@ the console you need to type::
 You need the telnet program which comes installed by default in Windows, and
 most Linux distros.
 
-Available aliases in the telnet console
-=======================================
+Available variables in the telnet console
+=========================================
 
 The telnet console is like a regular Python shell running inside the Scrapy
-process, so you can do anything from it including imports, etc. 
+process, so you can do anything from it including importing new modules, etc. 
 
-However, the telnet console comes with some default shortcuts defined for
+However, the telnet console comes with some default variables defined for
 convenience:
 
 +----------------+-------------------------------------------------------------------+
@@ -126,3 +126,17 @@ To stop::
     >>> engine.stop()
     Connection closed by foreign host.
 
+Telnet Console signals
+======================
+
+.. signal:: update_telnet_vars
+.. function:: update_telnet_vars(telnet_vars)
+
+    Sent just before the telnet console is opened. You can hook up to this
+    signal to add, remove or update the variables that will be available in the
+    telnet local namespace. In order to do that, you need to update the
+    ``telnet_vars`` dict in your handler.
+
+    :param telnet_vars: the dict of telnet variables
+    :type telnet_vars: dict
+

scrapy/conf/default_settings.py

@@ -110,7 +110,7 @@ EXTENSIONS = {}
 EXTENSIONS_BASE = {
     'scrapy.contrib.corestats.CoreStats': 0,
     'scrapy.management.web.WebConsole': 0,
-    'scrapy.management.telnet.TelnetConsole': 0,
+    'scrapy.telnet.TelnetConsole': 0,
     'scrapy.contrib.webconsole.scheduler.SchedulerQueue': 0,
     'scrapy.contrib.webconsole.livestats.LiveStats': 0,
     'scrapy.contrib.webconsole.spiderctl.Spiderctl': 0,

scrapy/telnet.py

@@ -15,6 +15,7 @@ from scrapy.core.exceptions import NotConfigured
 from scrapy.core.manager import scrapymanager
 from scrapy.spider import spiders
 from scrapy.stats import stats
+from scrapy.utils.signal import send_catch_log
 from scrapy.utils.trackref import print_live_refs
 from scrapy.utils.engine import print_engine_status
 from scrapy.conf import settings
@@ -25,30 +26,38 @@ try:
 except ImportError:
     hpy = None
 
-# if you add entries here also update topics/telnetconsole.rst
-telnet_namespace = {
-    'engine': scrapymanager.engine,
-    'manager': scrapymanager,
-    'extensions': extensions,
-    'stats': stats,
-    'spiders': spiders,
-    'settings': settings,
-    'est': print_engine_status,
-    'p': pprint.pprint,
-    'prefs': print_live_refs,
-    'hpy': hpy,
-}
+# signal to update telnet variables
+# args: telnet_vars
+update_telnet_vars = object()
 
-def makeProtocol():
-    return telnet.TelnetTransport(telnet.TelnetBootstrapProtocol,
-        insults.ServerProtocol, manhole.Manhole, telnet_namespace)
 
 class TelnetConsole(protocol.ServerFactory):
 
     def __init__(self):
         if not settings.getbool('TELNETCONSOLE_ENABLED'):
             raise NotConfigured
-        self.protocol = makeProtocol
         self.noisy = False
         port = settings.getint('TELNETCONSOLE_PORT')
         reactor.callWhenRunning(reactor.listenTCP, port, self)
+
+    def protocol(self):
+        telnet_vars = self._get_telnet_vars()
+        return telnet.TelnetTransport(telnet.TelnetBootstrapProtocol,
+            insults.ServerProtocol, manhole.Manhole, telnet_vars)
+
+    def _get_telnet_vars(self):
+        # Note: if you add entries here also update topics/telnetconsole.rst
+        telnet_vars = {
+            'engine': scrapymanager.engine,
+            'manager': scrapymanager,
+            'extensions': extensions,
+            'stats': stats,
+            'spiders': spiders,
+            'settings': settings,
+            'est': print_engine_status,
+            'p': pprint.pprint,
+            'prefs': print_live_refs,
+            'hpy': hpy,
+        }
+        send_catch_log(update_telnet_vars, telnet_vars=telnet_vars)
+        return telnet_vars