Merge pull request #1 from jobe3774/command_via_get

Enabled command invocation via HTTP GET request

Author: jobe3774

README.md

@@ -197,6 +197,20 @@ and invokes the method. The response of this HTTP POST request will be your JSON
 ``` 
 Since remain untouched, you can attach any other information with that command such as an element-id of your frontend invoking it.
 
+Starting with version 1.1.0, you can also use HTTP GET requests to invoke commands. The request has to following structure:
+
+```
+ /cmd?name=command&arg1=val1&arg2=val2...&argN=valN
+```
+
+So for the above mentioned example **theDoorBell.switchDoorBell**, the correct request would be:
+
+```
+ /cmd?name=theDoorBell.switchDoorBell&onoff=off
+```
+
+The **RaspendHTTPServerThread** invokes the command and responds with the result of the invocation as a JSON string.
+
 ## How to install?
 
 Make sure you have installed Python 3.5 or higher. I've tested the package on my Raspberry Pi 3 Model B+ running **Raspbian GNU/Linux 9 (stretch)** with Python 3.5.3 installed. 

raspend.pyproj

@@ -5,7 +5,7 @@
     <SchemaVersion>2.0</SchemaVersion>
     <ProjectGuid>{d0fd4413-717c-4da2-b189-4cc8bdecbc68}</ProjectGuid>
     <ProjectHome />
-    <StartupFile>example2.py</StartupFile>
+    <StartupFile>example1.py</StartupFile>
     <SearchPath />
     <WorkingDirectory>.</WorkingDirectory>
     <OutputPath>.</OutputPath>

raspend/http.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 #
 #  The HTTP request handling interface for raspend.
-#  'raspend' stands for RaspberryPi EndPoint.
+#  'raspend' stands for RaspberryPi Backend.
 #  
 #  License: MIT
 #  
@@ -11,6 +11,7 @@
 from functools import partial
 from http.server import BaseHTTPRequestHandler
 import json
+import urllib
 
 from .utils import stoppablehttpserver
 
@@ -181,28 +182,81 @@ def onGetCmds(self):
         self.dataLock.release()
         return strJsonResponse
 
+    def onGetCmd(self, queryParams):
+        """ Call a command via HTTP GET. The response will be the command's return value as a JSON string.
+        """
+        strJsonResponse = ""
+
+        cmdName = queryParams["name"][0]
+        cmdArgs = dict()
+
+        cmd = self.commandMap.get(cmdName)
+
+        if cmd == None:
+            self.send_error(404, ("Command '{0}' not found!".format(cmdName)))
+            return
+
+        del (queryParams["name"])
+
+        for k,v in queryParams.items():
+            cmdArgs[k] = v[0]
+
+        result = ""
+
+        try:
+            result = cmd.execute(cmdArgs)
+        except Exception as e:
+            self.send_error(500, "An unexpected error occured during execution of '{0}'! Exception: {1}".format(cmdName, e))
+            return
+
+        strJsonResponse = json.dumps(result, ensure_ascii=False)
+            
+        try:
+            self.send_response(200)
+            self.send_header('Content-type', 'application/json; charset=utf-8')
+            self.send_header('Access-Control-Allow-Origin', '*')
+            self.end_headers()
+            self.wfile.write(bytes(strJsonResponse, 'utf-8'))
+        except OSError:
+            self.send_error(500)
+        except BlockingIOError:
+            self.send_error(500)
+        except Exception as e:
+            self.send_error(500, "An unexpected error occured during execution of '{0}'! Exception: {1}".format(cmdName, e))
+        return
+
     def do_GET(self):
         """ Handle HTTP GET request
 
             '/data'     : returns the whole 'dataDict' as JSON string
             '/data/key' : returns sub-element of 'dataDict' as JSON string
             '/cmds'     : returns the list of available commands
         """
+        urlComponents = urllib.parse.urlparse(self.path)
+        queryParams = urllib.parse.parse_qs(urlComponents.query)
+
         strJsonResponse = ""
-        
-        if self.path.lower() == "/cmds":
+
+        if urlComponents.path.lower() == "/cmds":
             if self.commandMap == None or len(self.commandMap) == 0:
-                self.send_error(501, "No commands available.")
+                self.send_error(501, "No commands available")
+                return
             else:
                 strJsonResponse = self.onGetCmds()
-        elif self.path == "/data" and self.dataDict != None:
+        elif urlComponents.path.lower() == "/cmd":
+            if self.commandMap == None or len(self.commandMap) == 0:
+                self.send_error(501, "No commands available")
+                return
+            else:
+                return self.onGetCmd(queryParams)
+        elif urlComponents.path.lower() == "/data" and self.dataDict != None:
             strJsonResponse = self.onGetRootDataPath()
-        elif self.path.startswith("/data/")  and self.dataDict != None:
+        elif urlComponents.path.startswith("/data/")  and self.dataDict != None:
             strJsonResponse = self.onGetDetailedDataPath()
         else:
             self.send_error(404)
             return
-
+        
         try:
             self.send_response(200)
             self.send_header('Content-type', 'application/json; charset=utf-8')

raspend/utils/commandmapping.py

@@ -79,10 +79,10 @@ def invoke(self, args):
         Check args and invoke callback method.
         """
         if not type(args) is dict:
-            return False
+            raise TypeError("Arguments need to be passed in a dictionary!")
         for key in args.keys():
             if not self.hasParameter(key):
-                return False
+                raise KeyError("No argument '{0}' found!".format(key))
         return self.__function(**args)
 
 class Command():

setup.py

@@ -12,7 +12,7 @@
 
 setuptools.setup(
     name="raspend",
-    version="1.0.2",
+    version="1.1.0",
     author="Joerg Beckers",
     author_email="pypi@jobe-software.de",
     description="A small and easy to use HTTP backend framework for the Raspberry Pi which is ideal for small to medium-sized home automation projects.",