[Twisted-web] Python and Cors
Donal McMullan
donal.mcmullan at gmail.com
Sun Aug 27 13:43:51 MDT 2017
Ah sorry Deve - I failed to paste the first like of the render_GET method.
# Import necessary files
import serial
from twisted.web.resource import Resource
# Setup Arduino at correct speed
try:
arduino = serial.Serial('/dev/ttyACM0', 9600)
except:
arduino = serial.Serial('/dev/ttyACM1', 9600)
class MoveServo(Resource):
isLeaf = True
permitted_origins = ('http://192.168.1.122:9000',)
def render_GET(self,request):
origin = request.getHeader('Origin')
if origin in (self.permitted_origins):
request.setHeader('Access-Control-Allow-Origin', origin)
try:
# Send value over serial to the Arduino
arduino.write(request.args['value'][0])
return 'Success'
except:
return 'Failure'
resource = MoveServo()
On 27 August 2017 at 19:01, Deve Krehbiel <deve at speedprint.com> wrote:
> This is what I get without your code:
> index1.html:1 XMLHttpRequest cannot load http://192.168.1.122:81/
> servos.rpy?value=70P. No 'Access-Control-Allow-Origin' header is present
> on the requested resource. Origin 'http://192.168.1.122:9000' is
> therefore not allowed access.
> jquery.min.js:4 XHR failed loading: GET "http://192.168.1.122:81/
> servos.rpy?value=70P".
>
> This is what I get with it:
> jquery.min.js:4 GET http://192.168.1.122:81/servos.rpy?value=100P
> send @ jquery.min.js:4
> ajax @ jquery.min.js:4
> r.(anonymous function) @ jquery.min.js:4
> move @ index1.html:54
> onclick @ index1.html:17
> index1.html:1 XMLHttpRequest cannot load http://192.168.1.122:81/
> servos.rpy?value=100P. No 'Access-Control-Allow-Origin' header is present
> on the requested resource. Origin 'http://192.168.1.122:9000' is
> therefore not allowed access. *The response had HTTP status code 500.*
> jquery.min.js:4 XHR failed loading: GET "http://192.168.1.122:81/
> servos.rpy?value=100P".
>
> I appreciate your efforts and if you have any other ideas... Thank You!
>
> Deve
>
> On Sun, Aug 27, 2017 at 12:48 PM, Deve Krehbiel <deve at speedprint.com>
> wrote:
>
>> Thank you for the response. In trying that code, it made it so the LAN
>> cannot move the buttons either. Here is the error list I got:
>>
>> *web.Server Traceback (most recent call last):*
>> exceptions.NameError: global name 'origin' is not defined
>> /usr/lib/python2.7/dist-packages/twisted/web/server.py:189 in process
>> 188 self._encoder = encoder
>> 189 self.render(resrc)
>> 190 except:
>> /usr/lib/python2.7/dist-packages/twisted/web/server.py:238 in render
>> 237 try:
>> 238 body = resrc.render(self)
>> 239 except UnsupportedMethod as e:
>> /usr/lib/python2.7/dist-packages/twisted/web/resource.py:250 in render
>> 249 raise UnsupportedMethod(allowedMethods)
>> 250 return m(request)
>> 251
>> /usr/local/www/servos.rpy:15 in render_GET
>> 14 def render_GET(self,request):
>> 15 if origin in (self.permitted_origins):
>> 16 request.setHeader('Access-Control-Allow-Origin', origin)
>> exceptions.NameError: global name 'origin' is not defined
>>
>> Deve
>>
>> On Sun, Aug 27, 2017 at 12:03 PM, Donal McMullan <
>> donal.mcmullan at gmail.com> wrote:
>>
>>> Perhaps you just need to set the 'Access-Control-Allow-Origin' header?
>>> Something like this might work:
>>>
>>>
>>> # Import necessary files
>>>
>>> import serial
>>>
>>> from twisted.web.resource import Resource
>>>
>>> # Setup Arduino at correct speed
>>>
>>> try:
>>>
>>> arduino = serial.Serial('/dev/ttyACM0', 9600)
>>>
>>> except:
>>>
>>> arduino = serial.Serial('/dev/ttyACM1', 9600)
>>>
>>>
>>>
>>> class MoveServo(Resource):
>>>
>>> isLeaf = True
>>>
>>> permitted_origins = ('http://192.168.1.122:9000',)
>>>
>>>
>>>
>>> def render_GET(self,request):
>>>
>>> if origin in (self.permitted_origins):
>>>
>>> request.setHeader('Access-Control-Allow-Origin', origin)
>>>
>>> try:
>>>
>>> # Send value over serial to the Arduino
>>>
>>> arduino.write(request.args['value'][0])
>>>
>>> return 'Success'
>>>
>>> except:
>>>
>>> return 'Failure'
>>>
>>>
>>>
>>> resource = MoveServo()
>>>
>>> On 27 August 2017 at 17:10, Deve Krehbiel <deve at speedprint.com> wrote:
>>>
>>>> First post so forgive me if I am not explaining this right.
>>>>
>>>> I am trying to make a baby cam and then heavily document it for
>>>> everyone to have access to. I am using a Raspberry Pi with Rasbian. I am
>>>> using mjpg-streamer for the streaming with no problems.
>>>>
>>>> The problem is I am also using two servos for pan and tilt. To
>>>> accomplish this I am using an Arduino Uno. This is so I can add IR lighting
>>>> for night vision, etc later. I am not a programmer so this is getting
>>>> frustrating after a few weeks of failure.
>>>>
>>>> How is it failing you might ask..well, its working perfectly with only
>>>> ONE exception:
>>>> Every time I push the button for left/right/up/down I get this:
>>>>
>>>> XMLHttpRequest cannot load http://192.168.1.122:81/servos
>>>> .rpy?value=100P. No 'Access-Control-Allow-Origin' header is present on
>>>> the requested resource. Origin 'http://192.168.1.122:9000' is
>>>> therefore not allowed access.
>>>>
>>>> On the local area network, it still works, but taking it to the
>>>> internet it does not.
>>>>
>>>> Here are the two programs that make this happen. One is servos.rpy and
>>>> the other is the supporting HTML/Get script;
>>>> ****
>>>> servos.rpy
>>>> -----------------------------------
>>>> # Import necessary files
>>>> import serial
>>>> from twisted.web.resource import Resource
>>>> # Setup Arduino at correct speed
>>>> try:
>>>> arduino = serial.Serial('/dev/ttyACM0', 9600)
>>>> except:
>>>> arduino = serial.Serial('/dev/ttyACM1', 9600)
>>>>
>>>> class MoveServo(Resource):
>>>> isLeaf = True
>>>> def render_GET(self,request):
>>>> try:
>>>> # Send value over serial to the Arduino
>>>> arduino.write(request.args['value'][0])
>>>> return 'Success'
>>>> except:
>>>> return 'Failure'
>>>>
>>>> resource = MoveServo()
>>>> ***
>>>>
>>>> Now for the HTML/Get script:
>>>>
>>>> **
>>>> <!doctype html>
>>>> <html>
>>>> <head>
>>>> <title>Make Use Of DIY Security Camera</title>
>>>> <style type="text/css">
>>>> #container {
>>>> /* center the content */
>>>> margin: 0 auto;
>>>> text-align: center;
>>>> }
>>>> </style>
>>>> </head>
>>>> <body>
>>>> <div id="container">
>>>> <img src="/?action=stream" /><br>
>>>> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jque
>>>> ry.min.js"></script><br />
>>>> <button onclick="servos.move('P', 10)">Left</button>
>>>> <button onclick="servos.move('P', -10)">Right</button>
>>>> <button onclick="servos.move('T', -10)">Down</button>
>>>> <button onclick="servos.move('T', 10)">Up</button>
>>>> </div>
>>>> </body>
>>>> <script>
>>>> var servos;
>>>> $( document ).ready(function() {
>>>> servos = moveServos();
>>>> });
>>>> function moveServos() {
>>>> // Store some settings, adjust to suit
>>>> var panPos = 70,
>>>> tiltPos = 90,
>>>> tiltMax = 170,
>>>> tiltMin = 45,
>>>> panMax = 170,
>>>> panMin = 20;
>>>> return {
>>>> move:function(servo, adjustment) {
>>>> var value;
>>>> if(servo == 'P') {
>>>> if(!((panPos >= panMax && adjustment > 0) || (panPos <= panMin &&
>>>> adjustment < 0))) {
>>>> // Still within allowed range, "schedule" the movement
>>>> panPos += adjustment;
>>>> }
>>>> value = panPos + 'P';
>>>> }
>>>> else if(servo == 'T') {
>>>> if(!((tiltPos >= tiltMax && adjustment > 0) || (tiltPos <= tiltMin &&
>>>> adjustment < 0))) {
>>>> // Still within allowed range, "schedule" the movement
>>>> tiltPos += adjustment;
>>>> }
>>>> value = tiltPos + 'T';
>>>> }
>>>> // Use AJAX to actually move the servo
>>>> $.get('http://192.168.1.122:81/servos.rpy?value=' + value);
>>>> },
>>>> }
>>>> }
>>>> </script>
>>>> </html>
>>>>
>>>> *****
>>>> Twisted is started: sudo twistd -n web -p 81 --path /usr/local/www/
>>>>
>>>> I would be forever grateful if someone could take a serious look at
>>>> this and tell me where I am going wrong. Once this is fixed, I can start
>>>> documenting the entire system for everyone. Thank you!
>>>>
>>>> Deve
>>>>
>>>> _______________________________________________
>>>> Twisted-web mailing list
>>>> Twisted-web at twistedmatrix.com
>>>> https://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-web
>>>>
>>>>
>>>
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>>>
>>>
>>
>
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