allow to use scrape command without an url

--HG--
extra : convert_revision : svn%3Ab85faa78-f9eb-468e-a121-7cced6da292c%40178

scrapy/trunk/scrapy/command/commands/scrape.py

@@ -20,11 +20,12 @@ def load_url(url, response):
     itemcls = load_class(settings['DEFAULT_ITEM_CLASS'])
     item = itemcls()
     vars['item'] = item
-    vars['url'] = url
-    vars['response'] = response
     vars['xxs'] = XmlXPathSelector(response)
     vars['hxs'] = HtmlXPathSelector(response)
-    vars['spider'] = spiders.fromurl(url)
+    if url:
+        vars['url'] = url
+        vars['response'] = response
+        vars['spider'] = spiders.fromurl(url)
     vars['get'] = get_url
     return vars
 
@@ -40,7 +41,7 @@ def print_vars(vars):
 
 class Command(ScrapyCommand):
     def syntax(self):
-        return "<url>"
+        return "[url]"
 
     def short_desc(self):
         return "Interactive scraping console"
@@ -53,23 +54,26 @@ class Command(ScrapyCommand):
         pass
 
     def run(self, args, opts):
-        if not args:
-            return False
-        url = args[0]
+        
+        url = None
+        if args:
+            url = args[0]
 
         print "Scrapy %s - Interactive scraping console\n" % scrapy.__version__
 
         print "Enabling Scrapy extensions...",
         extensions.load()
         print "done"
-        print "Downloading URL...           ",
-        responses = fetch([url])
-        print "done"
-        if not responses:
-            if not opts.loglevel:
-                print 'Nothing downloaded, run with -o DEBUG to see why it failed'
-            return
-        response = responses[0]
+        response = None
+        if url:
+            print "Downloading URL...           ",
+            responses = fetch([url])
+            print "done"
+            if not responses:
+                if not opts.loglevel:
+                    print 'Nothing downloaded, run with -o DEBUG to see why it failed'
+                return
+            response = responses[0]
 
         vars = load_url(url, response)
         self.update_vars(vars)