add simple request method handling

- can register callbacks on specific HTTP methods and paths
- Can call update_poll in event loop to check for new incoming requests
- update server example script

Author: mscosti

adafruit_esp32spi/adafruit_esp32spi_requests.py

@@ -204,23 +204,11 @@ def request(method, url, data=None, json=None, headers=None, stream=False, timeo
         reason = ""
         if len(line) > 2:
             reason = line[2].rstrip()
-        while True:
-            line = sock.readline()
-            if not line or line == b"\r\n":
-                break
-
-            #print("**line: ", line)
-            title, content = line.split(b': ', 1)
-            if title and content:
-                title = str(title.lower(), 'utf-8')
-                content = str(content, 'utf-8')
-                resp.headers[title] = content
-
-            if line.startswith(b"Transfer-Encoding:"):
-                if b"chunked" in line:
-                    raise ValueError("Unsupported " + line)
-            elif line.startswith(b"Location:") and not 200 <= status <= 299:
-                raise NotImplementedError("Redirects not yet supported")
+        resp.headers = self.parse_headers(sock)
+        if "chunked" in resp.headers.get("transfer-encoding"):
+            raise ValueError("Unsupported " + line)
+        elif resp.headers.get("location") and not 200 <= status <= 299:
+            raise NotImplementedError("Redirects not yet supported")
 
     except:
         sock.close()
@@ -232,6 +220,27 @@ def request(method, url, data=None, json=None, headers=None, stream=False, timeo
 # pylint: enable=too-many-branches, too-many-statements, unused-argument
 # pylint: enable=too-many-arguments, too-many-locals
 
+def parse_headers(sock):
+    """
+    Parses the header portion of an HTTP request/response from the socket.
+    Expects first line of HTTP request/response to have been read already
+    return: header dictionary
+    rtype: Dict
+    """
+    headers = {}
+    while True:
+        line = sock.readline()
+        if not line or line == b"\r\n":
+            break
+
+        #print("**line: ", line)
+        title, content = line.split(b': ', 1)
+        if title and content:
+            title = str(title.lower(), 'utf-8')
+            content = str(content, 'utf-8')
+            headers[title] = content
+    return headers
+
 def head(url, **kw):
     """Send HTTP HEAD request"""
     return request("HEAD", url, **kw)

adafruit_esp32spi/adafruit_esp32spi_server.py

@@ -31,7 +31,8 @@
 """
 
 from micropython import const
-import adafruit_esp32spi_socket as socket
+import adafruit_esp32spi.adafruit_esp32spi_socket as socket
+from adafruit_esp32spi.adafruit_esp32spi_requests import parse_headers
 
 _the_interface = None   # pylint: disable=invalid-name
 def set_interface(iface):
@@ -51,6 +52,7 @@ def __init__(self, port=80, debug=False):
         self._server_sock = socket.socket(socknum=NO_SOCK_AVAIL)
         self._client_sock = socket.socket(socknum=NO_SOCK_AVAIL)
         self._debug = debug
+        self._listeners = {}
 
 
     def start(self):
@@ -62,11 +64,43 @@ def start(self):
             print("Server available at {0}:{1}".format(ip, self.port))
             print("Sever status: ", _the_interface.get_server_state(self._server_sock.socknum))
 
+    def on(self, method, path, request_handler):
+        """
+        Register a Request Handler for a particular HTTP method and path.
+        request_handler will be called whenever a matching HTTP request is received.
+
+        request_handler should accept the following args:
+            (Dict headers, bytes body, Socket client)
+        :param str method: the method of the HTTP request
+        :param str path: the path of the HTTP request
+        :param func request_handler: the function to call
+        """
+        self._listeners[self._get_listener_key(method, path)] = request_handler
+
+    def update_poll(self):
+        client = self.client_available()
+        if (client and client.available()):
+            line = client.readline()
+            method, path, ver = line.split(None, 2)
+            key = self._get_listener_key(method, path)
+            if key in self._listeners:
+                headers = parse_headers(client)
+                body = client.read()
+                print("headers: ", headers)
+                print("body: ", body)
+                self._listeners[key](headers, body, client)
+            else:
+                # TODO: support optional custom 404 callback?
+                client.write(b"HTTP/1.1 404 NotFound\r\n")
+                client.close()
+
+
     def client_available(self):
         """
-        returns a client socket connection if available.otherwise, returns a non available socket
-        :return the client
-        :rtype Socket
+        returns a client socket connection if available.
+        Otherwise, returns None
+        :return: the client
+        :rtype: Socket
         """
         sock = None
         if self._server_sock.socknum != NO_SOCK_AVAIL:
@@ -91,4 +125,7 @@ def client_available(self):
             self._client_sock = sock
             return self._client_sock
 
-        return socket.socket(socknum=NO_SOCK_AVAIL)
+        return None
+
+    def _get_listener_key(self, method, path):
+        return "{0}|{1}".format(str(method.lower(), 'utf-8'), str(path, 'utf-8'))

adafruit_esp32spi/adafruit_esp32spi_socket.py

@@ -162,14 +162,15 @@ def connected(self):
             return True
         else:
             status = _the_interface.socket_status(self.socknum)
-            result = status not in (esp.SOCKET_LISTEN,
-                                    esp.SOCKET_CLOSED,
-                                    esp.SOCKET_FIN_WAIT_1,
-                                    esp.SOCKET_FIN_WAIT_2,
-                                    esp.SOCKET_TIME_WAIT,
-                                    esp.SOCKET_SYN_SENT,
-                                    esp.SOCKET_SYN_RCVD,
-                                    esp.SOCKET_CLOSE_WAIT)
+            # TODO: why is esp.<ConstantName> not defined? using magic numbers in mean time
+            result = status not in (1,
+                                    0,
+                                    5,
+                                    6,
+                                    10,
+                                    2,
+                                    3,
+                                    7)
             if not result:
                 self.close()
                 self._socknum = NO_SOCKET_AVAIL

examples/esp32spi_server.py

@@ -20,35 +20,53 @@
 esp32_reset = DigitalInOut(board.D7)
 esp32_gpio0 = DigitalInOut(board.D12)
 
+"""Use below for Most Boards"""
+# status_light = neopixel.NeoPixel(board.NEOPIXEL, 1, brightness=0.2) # Uncomment for Most Boards
+"""Uncomment below for ItsyBitsy M4"""
+import adafruit_dotstar as dotstar
+status_light = dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI, 1, brightness=1)
+
 
 spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
 esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset, gpio0_pin=esp32_gpio0, debug=False)
 
 ## Connect to wifi with secrets
-wifi = wifimanager.ESPSPI_WiFiManager(esp, secrets, debug=True)
+wifi = wifimanager.ESPSPI_WiFiManager(esp, secrets, status_light, debug=True)
 wifi.connect()
 
 server.set_interface(esp)
-server = server.server(80, True)
-server.start()
+server = server.server(80, debug=False)
 
-print("IP addr: ", esp.pretty_ip(esp.ip_address))
-print("server started!")
 
+def onLedHigh(headers, body, client):
+    print("led on!")
+    status_light.fill((0, 0, 100))
+    respond(headers, body, client)
 
-while True:
+def onLedLow(headers, body, client):
+    print("led off!")
+    status_light.fill(0)
+    respond(headers, body, client)
+
+def respond(headers, body, client):
+    client.write(b"HTTP/1.1 200 OK\r\n")
+    client.write(b"Content-type:text/html\r\n")
+    client.write(b"\r\n")
+
+    client.write(b"Click <a href=\"/H\">here</a> turn the LED on!!!<br>\r\n")
+    client.write(b"Click <a href=\"/L\">here</a> turn the LED off!!!!<br>\r\n")
 
-    client = server.client_available()
-    if (client.available()):
-        data = client.read()
-        if len(data):
-            print(data)
-            client.write(b"HTTP/1.1 200 OK\r\n")
-            client.write(b"Content-type:text/html\r\n")
-            client.write(b"\r\n")
+    client.write(b"\r\n")
+    client.close()
 
-            client.write(b"Click <a href=\"/H\">here</a> turn the LED on!!!<br>\r\n")
-            client.write(b"Click <a href=\"/L\">here</a> turn the LED off!!!!<br>\r\n")
+server.on("GET", "/", respond)
+server.on("GET", "/H", onLedHigh)
+server.on("GET", "/L", onLedLow)
 
-            client.write(b"\r\n")
-            client.close()
+
+print("IP addr: ", esp.pretty_ip(esp.ip_address))
+
+server.start()
+print("server started!")
+while True:
+    server.update_poll()