The problem is that get vars userd to pass json arguments are always
strings.
On Jul 21, 2:38 pm, Michael Ellis <michael.f.el...@gmail.com> wrote:
> In a data acquisition system, I need to handle reports for sensor
> channels that may not have anything connected to them. The relevant
> fields in my table definition look like:
>
> Field('f_ch1_value_double', type = 'double', default = None,
> label = T("CH1")),
> Field('f_ch2_value_double', type = 'double', default = None,
> label = T("CH2")),
> Field('f_ch3_value_double', type = 'double', default = None,
> label = T("CH3")),
> Field('f_ch4_value_double', type = 'double', default = None,
> label = T("CH4")),
> Field('f_ch5_value_double', type = 'double', default = None,
> label = T("CH5")),
> Field('f_ch6_value_double', type = 'double', default = None,
> label = T("CH6")),
>
> and I have a function that starts like this:
>
> @service.json
> def v2_data_insert(timestamp, sensorid,
> ch1=None, ch2=None, ch3=None, ch4=None, ch5=None,
> ch6=None,
> flowrate=None, flowtemp=None, erate=None,
> chargev=None, battv=None, sensorv=None):
>
> db.t_v2_data[0] = dict(f_timestamp_datetime = timestamp,
> f_sensor_reference = sensorid,
> f_ch1_value_double = ch1,
> f_ch2_value_double = ch2,
> f_ch3_value_double = ch3,
> f_ch4_value_double = ch4,
> f_ch5_value_double = ch5,
> f_ch6_value_double = ch6,
> f_flow_rate_double = flowrate,
> f_flow_temp_double = flowtemp,
> f_energy_rate_double = erate,
> f_battery_charger_double = chargev,
> f_battery_volts_double = battv,
> f_sensor_volts_double = sensorv)
>
> Passing None to any of the channel arguments, e.g. ch1 = None, is
> raising
>
> ValueError: could not convert string to float: None
>
> on the insert call even though null is allowed by the field
> definition. I suspect this must be an issue with the way
> urllib.urlencode() the dictionary containing the channel values before
> the data is posted to my controller.
>
> The process that sends the data is doing the following:
>
> encodeddata = urllib.urlencode(data)
> response = urllib2.urlopen(server + url, encodeddata)
>
> where data is the dictionary that maps to the keyword arguments of
> v2_data_insert().
>
> I can hack around this issue by testing for 'None' as a string value
> in the controller, but I'd be grateful for a more elegant soution.
>
> Thanks,
> Mike
