System information

same => n(unavail),VoiceMail(${CurrentExten}@shifteight,u)
same => n,Hangup()
And here is a slightly more elaborate section of dialplan that utilizes a few of the tools
we’ve learned throughout the book, including DB_EXISTS(), GotoIf(), and the IF()
function:
exten => _3XXX,1,Verbose(2,Simple calendar busy check example)
same => n,Set(CurrentExten=${EXTEN})
same => n,GotoIf($[${DB_EXISTS(extension/${CurrentExten}/device)}]?:no_device,1)
same => n,Set(CurrentDevice=${DB_RESULT})
same => n,GotoIf($[${DB_EXISTS(extension/${CurrentExten}/calendar)}]?:no_calendar)
same => n,Set(CalendarBusy=${CALENDAR_BUSY(${DB_RESULT})})
same => n,GotoIf($[${CalendarBusy}]?voicemail,1)
same => n(no_calendar),Verbose(2,No calendar was found for this user)
same => n,Dial(SIP/${CurrentDevice},30)
same => n,Goto(voicemail,1)
exten => voicemail,1,Verbose(2,Sending caller to voicemail)
; *** This line should not have any line breaks
same => n,GotoIf($[${DB_EXISTS(extension/${CurrentExten}/voicemail_context)}]
?:no_voicemail)
same => n,Set(VoiceMailContext=${DB_RESULT})
; *** This line should not have any line breaks
same => n,Set(VoiceMailStatus=${IF($["${DIALSTATUS}" = "BUSY" |
0${CalendarBusy}]?b:u)})
same => n,VoiceMail(${CurrentExten}@${VoiceMailContext},${VoiceMailStatus})
same => n,Hangup()
same => n(no_voicemail),Playback(number-not-answering)
same => n,Hangup()
exten => no_device,1,Verbose(2,No device found in the DB)
same => n,Playback(invalid)
same => n,Hangup()
Writing Call Information to a Calendar
Using the CALENDAR_WRITE() function opens some other possibilities in terms of calendar
integration. From the Asterisk dialplan, we can insert information into a calendar,
which can be consumed by other devices and applications. Our next example is a cal-
endar that tracks call logs. For anyone who may be on the phone a fair amount who
needs to track time for clients, writing all calls to a calendar for a visual reference can
be useful when verifying things at the end of the day.
We’re going to utilize the Google web calendar again for this example, but we’re going
to create a new, separate calendar just for tracking calls. In order to write to the calendar,
we’ll need to set up our calendar.conf file a little bit differently, by using the CalDAV
calendar format. First, though, we need to create our new calendar.
408 | Chapter 18: External Services