Page 311 - Asterisk™: The Future of Telephony

read=SELECT extension FROM ast_hotdesk WHERE status = '1'
AND location = '${ARG1}' ORDER BY id LIMIT '1' OFFSET '${ARG2}'
Now that we know what extension we want to update, we write to the HOTDESK_STATUS
() function, and assign a 0 to the status column where the extension number matches
the value in the ${WHO} variable (i.e., 1101). We then end the loop with EndWhile() and
return back to the valid_login extension at the set_login_status priority label (as dis-
cussed previously):
exten => logout_login,n,Set(HOTDESK_STATUS(${WHO})=0) ; logout phone
exten => logout_login,n,Set(ROW_COUNTER=$[${ROW_COUNTER} + 1])
exten => logout_login,n,EndWhile()
exten => logout_login,n,Goto(valid_login,set_login_status) ; return to logging in
The rest of the context should be fairly straightforward (if some of this doesn’t make
sense, we suggest you go back and refresh your memory with Chapter 5 and Chap-
ter 6). The one trick you may be unfamiliar with could be the usage of the ${ODB
CROWS} channel variable, which is set by the HOTDESK_STATUS() function. This tells us
how many rows were affected in the SQL UPDATE, which we assume to be 1. If the value
of ${ODBCROWS} is less than 1, then we assume an error and handle appropriately:
exten => logout,1,NoOp()
exten => logout,n,Set(HOTDESK_STATUS(${E})=0)
exten => logout,n,GotoIf($[${ODBCROWS} < 1]?error,1)
exten => logout,n,Playback(silence/1&agent-loggedoff)
exten => logout,n,Hangup()
exten => login_fail,1,NoOp()
exten => login_fail,n,Playback(silence/1&login-fail)
exten => login_fail,n,Hangup()

exten => error,1,NoOp()
exten => error,n,Playback(silence/1&connection-failed)
exten => error,n,Hangup()

exten => invalid_user,1,NoOp()
exten => invalid_user,n,Verbose(1|Hot Desk extension ${E} does not exist)
exten => invalid_user,n,Playback(silence/2&invalid)
exten => invalid_user,n,Hangup()
We also include the hotdesk_outbound context which will handle our outgoing calls
after we have logged the agent in to the system:
include => hotdesk_outbound
The hotdesk_outbound context utilizes many of the same principles and usage as pre-
viously discussed, so we won’t approach it quite so thoroughly, but essentially the
[hotdesk_outbound] context will catch all dialed numbers from the desk phones. We first
set our LOCATION variable using the CHANNEL variable, then determine which extension
(agent) is logged in to the system and assign it to the WHO variable. If this variable is
NULL, then we reject the outgoing call. If not NULL, then we get the agent information
using the HOTDESK_INFO() function and assign it to several CHANNEL variables. This

Getting Funky with func_odbc: Hot-Desking | 283