我有一个问题。
我有一个页面，我将命令发送到传感器网络。
当我点击这部分代码时
<a href='javascript:void(send_command_to_sensor("{{net.id}}", "{{sens.id}}", "identify"));'></a>
我调用js函数，这个：
function send_command_to_sensor(net, sens, command) {
$.ajax({url: "/networks/" + net + "/sensors/" + sens + "/send?command=" + command,
type: "GET",
async: true,
dataType: "json",
success: function(json_response) {
var err = json_response['error'];
if (err) {
show_alert('error', err);
return;
}
var success = json_response['success'];
if (success) {
show_alert('success', success);
return;
}
show_alert('alert', "This should not happen!");
}
});
}
此函数构建一个url，用于调用用python编写的Tornado Web服务器中的处理程序。处理程序是这样的：
################################################################################
# SensorSend handler.
# Sends a packet to the sensor by writing in a file (Should work through
# MySQL database) read by Quantaserv Daemon
################################################################################
class SensorSendHandler(BaseHandler):
# Requires authentication
@tornado.web.authenticated
def get(self, nid, sid):
command = self.get_argument('command').upper();
print command
# Retrieve the current user
usr = self.get_current_user()
usr_id = usr['id']
self.lock_tables("read", ['nets_permissions as n'])
perm = self.db.get("SELECT n.perm FROM nets_permissions as n \
WHERE n.network_id=%s AND n.user_id=%s", nid, int(usr_id))
self.unlock_tables()
# Check whether the user has access to the network
perms = self.check_network_access(nid, perm['perm'])
#Check wether the sensor exists in this network
self.check_sensor_in_network(sid, nid)
# The dictionary to return
ret = {}
############################################################################
# The following Code is valid for ZTC networks only
# Must be generalized
# TODO: - get the network type:
# - check wether the command is allowed
############################################################################
if command not in ['ON', 'OFF', 'TOGGLE', 'IDENTIFY']:
raise tornado.web.HTTPError(404, "Unknown command: " + str(command))
#Command OnOffCmd_SetState
if command in ['ON', 'OFF', 'TOGGLE']:
op_group = "70"
op_code = "50"
packet_meta = "%s%s%s%s02%s%s600080000%s"
pkt_len = hextransform(16, 2)
netid = hextransform(int(nid), 16)
sens_id = hextransform(int(sid) >> 16, 4)
sens_id_little = invert2bytes(sens_id,0)
cluster_id = hextransform(int(sid) & 0x00FFFF, 4)
end_point = "08"
if command == 'ON':
cmd_data = "01"
elif command == 'OFF':
cmd_data = "00"
elif command == 'TOGGLE':
cmd_data = "02"
packet = packet_meta % (netid, op_group, op_code, pkt_len, sens_id, end_point, cmd_data)
packet = packet.upper()
op_group_hex=0x70
op_code_hex=0x50
print command
#Command ZDP-IEEE_addr.Request
elif command == 'IDENTIFY':
op_group = "A2"
op_code = "01"
packet_meta = "%s%s%s%s"
pkt_len = hextransform(2, 2)
sens_id = hextransform(int(sid) >> 16, 4)
sens_id_little = invert2bytes(sens_id,0)
packet = packet_meta % (op_group, op_code, pkt_len, sens_id)
packet = packet.upper()
op_group_hex=0xA2
op_code_hex=0x01
#Command ZDP-Active_EP_req.Request
elif command == 'HOWMANY':
op_group = "A2"
op_code = "05"
packet_meta = "%s%s%s%s%s"
pkt_len = hextransform(4, 2)
netid = hextransform(int(nid), 16)
sens_id = hextransform(int(sid) >> 16, 4)
sens_id_little = invert2bytes(sens_id,0)
packet = packet_meta % (op_group, op_code, pkt_len, sens_id, netid)
packet = packet.upper()
op_group_hex=0xA2
op_code_hex=0x05
mynet_type ="ztc"
cmdjson = packet2json(op_group_hex,op_code_hex, packet)
print("\t\t " + packet + "\n")
#
#
#TODO : -write command into db
ts = datetime.datetime.now().isoformat()
self.lock_tables("write", ['confcommands'])
self.db.execute("INSERT INTO confcommands (network_id, ntype, timestamp, command) \
VALUES (%s,%s,%s,%s)", nid, mynet_type, ts, cmdjson)
self.unlock_tables();
############### ELISA ##########################################
# TODO: - open the /tmp/iztc file in append mode
cmdfile = open('/tmp/iztc', 'a')
# - acquire a lock "only for the DB case, it's easier"
# - write the packet
cmdfile.write(nid + "\t"+ mynet_type + "\t"+ ts + "\t"+ cmdjson +"\n");
# - release the lock "only for the DB case, it's easier"
# - close the file
cmdfile.close()
if command == 'HOWMANY':
opcodegroupr = "A0"
opcoder = "85"
elif command == 'IDENTIFY':
opcodegroupr = "A0"
opcoder = "81"
print command
#Code for retrieving the MAC address of the node
como_url = "".join(['http://', options.como_address, ':', options.como_port,
'/', ztc_config, '?netid=', netid,
'&opcode_group=', opcodegroupr,
'&opcode=', opcoder, '&start=-5m&end=-1s'])
http_client = AsyncHTTPClient()
response = yield tornado.gen.Task(http_client.fetch, como_url)
ret = {}
if response.error:
ret['error'] = 'Error while retrieving unregistered sensors'
else:
for line in response.body.split("\n"):
if line != "":
value = int(line.split(" ")[6])
ret['response'] = value
self.write(tornado.escape.json_encode(ret))
if command == 'HOWMANY':
status = value[0]
NwkAddress = value[1:2]
ActiveEPCount = value[3]
ActiveEPList = value[len(ActiveEPCount)]
if status == "0":
ret['success'] = "The %s command has been succesfully sent!" % (command.upper())
self.write(tornado.escape.json_encode(ret))
elif status == "80":
ret['error'] = "Invalid Request Type"
self.write(tornado.escape.json_encode(ret))
elif status == "89":
ret['error'] = "No Descriptor"
self.write(tornado.escape.json_encode(ret))
else:
ret['error'] = "Device not found!"
self.write(tornado.escape.json_encode(ret))
if command == 'IDENTIFY':
status = value[0]
IEEEAddrRemoteDev = value[1:8]
NWKAddrRemoteDev = value[9:2]
NumOfAssociatedDevice = value[11:1]
StartIndex = value[12:1]
ListOfShortAddress = value[13:2*NumOfAssociatedDevice]
if status == "0":
ret['success'] = "Command succesfully sent! The IEEE address is: %s" % (IEEEAddrRemoteDev)
self.write(tornado.escape.json_encode(ret))
elif status == "80":
ret['success'] = "Invalid Request Type"
self.write(tornado.escape.json_encode(ret))
else:
ret['error'] = "Device Not Found"
self.write(tornado.escape.json_encode(ret))
我在开发者consolle中收到的错误是：
未捕获的TypeError：无法读取null的属性'error' $ .ajax.successwsn.js：26 jQuery.Callbacks.firejquery-1.7.2.js：1075 jQuery.Callbacks.self.fireWithjquery-1.7.2.js：1193 donejquery-1.7.2.js：7538 jQuery.ajaxTransport.send.callback
在js函数中。为什么功能不知道'错误'或'成功'？问题出在哪儿？？？？我认为程序不会在处理程序中输入，而是在js函数之后被阻塞。
非常感谢您的帮助！这是一个很长的帖子，但它很容易阅读！请！
答案 0 :(得分：1)
快速阅读是功能未正确装饰。
该行
response = yield tornado.gen.Task(http_client.fetch, como_url)
意味着你应该如此声明这个功能：
@tornado.web.asynchronous
@tornado.gen.engine
@tornado.web.authenticated
def get(self):
....
请注意添加两个额外的装饰器。