Webserver for using the editor with server-side storage.

webserver.py

@@ -0,0 +1,144 @@
+#!/usr/bin/env python
+
+# Webserver for teletext editor with rest API
+
+# Copyright 2015 Alistair Buxton <a.j.buxton@gmail.com>
+
+# API:
+
+# GET /<page>/<subpage>/
+# Load subpage from disk at /data/<page>/<subpage>.tt and return
+# it in url encoded fashion. Return a 404 if the subpage does not
+# exist.
+
+# POST /<page>/<subpage>/
+# Receive a url encoded subpage in POST body and save it to disk
+# at /data/<page>/<subpage>.tt. Creates any directories as required.
+
+# GET /edit/<page>/<subpage>/
+# Attempt to load subpage from disk at /data/<page>/<subpage>.tt
+# If successful, serve a 303 redirect to:
+#   /editor/<page>/<subpage>/#<urlendcodedpage>
+# If unsuccessful, serve a 303 redirect to:
+#   /editor/<page>/<subpage>/# (ie a blank subpage)
+
+# GET /editor/<page>/<subpage>/
+# Serve the teletext-editor.html
+
+# Notes
+
+# The editor does not have capability to POST pages, but this is
+# the only feature which needs to be implemented for this whole
+# thing to work. However, since this feature does not exist,
+# I have not tested the code paths for POSTing subpages.
+
+# Currently disk files are just a text file with the url encoded
+# string. But by reimplementing storage2url and url2storage the
+# pages can be stored in any format, including that used by
+# pyteletext, which in combination with raspi-teletext would enable
+# live editing of a service generated on raspberry pi.
+
+# HEAD requests are not implemented.
+
+from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer
+
+import os, errno
+
+ADDR = "localhost"
+PORT = 8000
+
+class RequestHandler(BaseHTTPRequestHandler):
+    editor = open('teletext-editor.html').read()
+
+    def datapath(self, page, create=False):
+        path = os.path.join('data', '%03x'%page)
+        if create:
+            try:
+                os.makedirs(path)
+            except OSError as exc:
+                if exc.errno == errno.EEXIST and os.path.isdir(path):
+                    pass
+                else: raise
+        return path
+
+    def storage2url(self, page, subpage):
+        # for now just read/write the string
+        filename = os.path.join(self.datapath(page), '%04x.tt'%subpage)
+        data = file(filename).read()
+        print filename, data
+        return data
+
+    def url2storage(self, page, subpage, urlencoded):
+        filename = os.path.join(self.datapath(page, create=True), '%04x.tt'%subpage)
+        f = file(filename, 'w')
+        f.write(urlencoded)
+        f.close()
+
+    def do_store_page(self, page, subpage):
+        self.url2storage(page, subpage, self.rfile.read())
+        self.send_response(200, "OK")
+        self.end_headers()
+        self.wfile.close()        
+
+    def do_get_page(self, page, subpage):
+        try:
+            urlencoded = self.storage2url(page, subpage)
+        except:
+            self.send_response(404, "Not found")
+            self.end_headers()
+            self.wfile.close()
+            return
+        self.send_response(200, "OK")
+        self.end_headers()
+        self.wfile.write(urlencoded)
+        self.wfile.close()
+
+    def do_edit(self, page, subpage):
+        try:
+            urlencoded = self.storage2url(page, subpage)
+        except:
+            urlencoded = ''
+        self.send_response(303, "OK")
+        self.send_header('Location', '/editor/%03x/%04x/#' % (page, subpage) + urlencoded)
+        self.end_headers()
+        self.wfile.close()
+
+    def do_GET(self):
+        try:
+            data = self.path.strip('/').split('/')
+            if len(data) == 2:
+                self.do_get_page(int(data[0], 16), int(data[1], 16))
+            elif len(data) == 3:
+                if data[0] == 'edit':
+                    self.do_edit(int(data[1], 16), int(data[2], 16))
+                elif data[0] == 'editor':
+                    self.send_response(200, "OK")
+                    self.end_headers()
+                    self.wfile.write(RequestHandler.editor)
+                    self.wfile.close()
+                else:
+                    raise "ERROR"
+            else:
+                raise "ERROR"
+        except:
+            self.send_response(500, "Error")
+            self.end_headers()
+            self.wfile.write("There has been an error\n")
+            self.wfile.close()
+
+    def do_POST(self):
+        try:
+            data = self.path.strip('/').split('/')
+            if len(data) == 2:
+                self.do_post_page(int(data[0], 16), int(data[1], 16))
+            else:
+                raise "ERROR"
+        except:
+            self.send_response(500, "Error")
+            self.end_headers()
+            self.wfile.write("There has been an error\n")
+            self.wfile.close()
+
+
+httpd = HTTPServer((ADDR, PORT), RequestHandler)
+httpd.serve_forever()