grid demo, shows POST data, compression, persistent connections, shared state

coro/http/demo/grid.py

+# -*- Mode: Python -*-
+
+import coro
+import coro.http
+import backdoor
+
+# toy: move an X through a grid.
+# tests: POST data, compression, persistent connections, shared state
+
+import sys
+W = sys.stderr.write
+
+class grid_handler:
+
+    def __init__ (self, w, h):
+        self.w = w
+        self.h = h
+        self.grid = [['.' for x in range (w)] for y in range (h)]
+        self.pos = [w/2, h/2]
+        self.grid[self.pos[1]][self.pos[0]] = 'X'
+
+    def match (self, request):
+        return request.path.startswith ('/grid')
+
+    def handle_request (self, request):
+        if request.path == '/grid/source':
+            request['content-type'] = 'text/plain'
+            request.set_deflate()
+            request.push (open ('grid.py', 'rb').read())
+            request.done()
+            return
+        request['content-type'] = 'text/html'
+        request.set_deflate()
+        if request.file:
+            data = request.file.read()
+            pairs = [ x.split('=') for x in data.split ('&') ]
+            for k, v in pairs:
+                if k == 'dir':
+                    x0, y0 = self.pos
+                    x1, y1 = self.pos
+                    if v == 'left':
+                        x1 = max (x0-1, 0)
+                    elif v == 'right':
+                        x1 = min (x0+1, self.w-1)
+                    elif v == 'up':
+                        y1 = max (y0-1, 0)
+                    elif v == 'down':
+                        y1 = min (y0+1, self.h-1)
+                    else:
+                        pass
+                    self.grid[y0][x0] = '*'
+                    self.grid[y1][x1] = 'X'
+                    self.pos = [x1, y1]
+        else:
+            pass
+        l = []
+        for y in self.grid:
+            l.append (''.join (y))
+        request.push ('<pre>')
+        request.push ('\n'.join (l))
+        request.push ('\n</pre>\n')
+        request.push (
+            '<form name="input" action="grid" method="post">'
+            '<input type="submit" name="dir" value="left" />'
+            '<input type="submit" name="dir" value="right" />'
+            '<input type="submit" name="dir" value="up" />'
+            '<input type="submit" name="dir" value="down" />'
+            '</form>'
+            '<a href="/grid/source">source for this handler</a>'
+            )
+        request.done()
+
+server = coro.http.server()
+server.push_handler (grid_handler (50, 30))
+server.push_handler (coro.http.handlers.coro_status_handler())
+server.push_handler (coro.http.handlers.favicon_handler())
+coro.spawn (server.start, ('0.0.0.0', 9001))
+coro.spawn (backdoor.serve, unix_path='/tmp/httpd.bd')
+coro.event_loop (30.0)