PicoWireless: ppwhttp add wildcard routes

This slightly reckless extension to ppwhttp adds support for wildcard routes, eg:

/get_led/<int:index>

Which will serve URLs in the form:

/get_led/10
/get_led/22

etc.

The wildcard includes <type:key>, attempting to match the behaviour of Flask.

Only type "int" is supported currently.

/get_led/<index> - would set data["index"] to a string
/get_led/<int:index> - would attempt to parse the URL part to an int, and would not serve eg: /get_led/hi

See plasma_ws2812_http.py for example usage.

micropython/examples/pico_wireless/plasma_ws2812_http.py

@@ -9,6 +9,8 @@ except ImportError:
 """
 This example uses the Plasma WS2812 LED library to drive a string of LEDs alongside the built-in RGB LED.
 You should wire your LEDs to VBUS/GND and connect the data pin to pin 27 (unused by Pico Wireless).
+
+Go to: https://<address>:<port>/set_led/<index> to set a single LED
 """
 
 NUM_LEDS = 30  # Number of connected LEDs
@@ -27,7 +29,7 @@ led_strip = plasma.WS2812(NUM_LEDS, LED_PIO, LED_SM, LED_PIN)
 # Edit your routes here
 # Nothing fancy is supported, just plain ol' URLs and GET/POST methods
 @ppwhttp.route("/", methods=["GET", "POST"])
-def get_home(method, url, data=None):
+def get_home(method, url, data):
     if method == "POST":
         global r, g, b
         r = int(data.get("r", 0))
@@ -46,6 +48,45 @@ def get_home(method, url, data=None):
 </form>""".format(r=r, g=g, b=b)
 
 
+# This wildcard route allows us to visit eg `/set_led/<index>`
+# to get/set the state of LED <index>
+# You should *probably* not modify state with GET, even though you can
+# so we use a form and POST to handle changing things.
+@ppwhttp.route("/set_led/<int:index>", methods=["GET", "POST"])
+def set_led(method, url, data):
+    i = int(data.get("index", 0))
+
+    if method == "POST":
+        r = int(data.get("r", 0))
+        g = int(data.get("g", 0))
+        b = int(data.get("b", 0))
+        led_strip.set_rgb(i, r, g, b)
+        print("Set LED to {} {} {}".format(r, g, b))
+    else:
+        # TODO Fix WS2812 / APA102 get methods to correct for colour order/alignment
+        r, g, b, w = led_strip.get(i)
+        r = int(r)
+        g = int(g)
+        b = int(b)
+
+    return """LED: {i}<br /><form method="post" action="/set_led/{i}">
+    <input id="r" name="r" type="number" value="{r}" />
+    <input name="g" type="number" value="{g}"  />
+    <input name="b" type="number" value="{b}"  />
+    <input type="submit" value="Set LED" />
+</form>""".format(i=i, r=r, g=g, b=b)
+
+
+# This wildcard route allows us to visit eg `/get_led/<index>`
+# to get the state of LED <index>
+@ppwhttp.route("/get_led/<int:index>", methods="GET")
+def get_led(method, url, data):
+    i = data.get("index", 0)
+    # TODO Fix WS2812 / APA102 get methods to correct for colour order/alignment
+    r, g, b, w = led_strip.get(i)
+    return "LED: {}<br />R: {:0.0f}<br />G: {:0.0f}<br />B: {:0.0f}".format(i, r, g, b)
+
+
 @ppwhttp.route("/test", methods="GET")
 def get_test(method, url):
     return "Hello World!"

micropython/examples/pico_wireless/ppwhttp.py

@@ -181,6 +181,38 @@ Connection: close
     picowireless.client_stop(client_sock)
 
 
+def find_route(route, url, method, data):
+    if len(url) > 0:
+        for key, value in route.items():
+            if key == url[0]:
+                return find_route(route[url[0]], url[1:], method, data)
+
+            elif key.startswith("<") and key.endswith(">"):
+                key = key[1:-1]
+                if ":" in key:
+                    dtype, key = key.split(":")
+                else:
+                    dtype = "str"
+
+                if dtype == "int":
+                    try:
+                        data[key] = int(url[0])
+                    except ValueError:
+                        continue
+
+                else:
+                    data[key] = url[0]
+
+                return find_route(value, url[1:], method, data)
+
+        return None, None
+
+    if method in route:
+        return route[method], data
+
+    return None, None
+
+
 def handle_http_request(server_sock, timeout=5000):
     t_start = time.ticks_ms()
 
@@ -221,16 +253,24 @@ def handle_http_request(server_sock, timeout=5000):
 
     response = None
 
+    data = {}
+
+    if url.startswith("/"):
+        url = url[1:]
+    url = url.split("/")
+    handler, data = find_route(routes, url, method, data)
+
     # Dispatch the request to the relevant route
-    if url in routes and method in routes[url] and callable(routes[url][method]):
+    if callable(handler):
         if method == "POST":
-            data = {}
             for var in body.split("&"):
                 key, value = var.split("=")
                 data[key] = value
-            response = routes[url][method](method, url, data)
+
+        if data == {}:
+            response = handler(method, url)
         else:
-            response = routes[url][method](method, url)
+            response = handler(method, url, data)
 
     if response is not None:
         response = "HTTP/1.1 200 OK\r\nContent-Length: {}\r\nContent-Type: text/html\r\n\r\n".format(len(response)) + response
@@ -249,10 +289,20 @@ def route(url, methods="GET"):
     if type(methods) is str:
         methods = [methods]
 
+    if url.startswith("/"):
+        url = url[1:]
+
+    url = url.split("/")
+
     def decorate(handler):
+        route = routes
+        for part in url:
+            if part not in route:
+                route[part] = {}
+
+            route = route[part]
+
         for method in methods:
-            if url not in routes:
-                routes[url] = {}
-            routes[url][method] = handler
+            route[method] = handler
 
     return decorate