SmartApp which subscribes to Smart Home Monitor status and maps the state to an attribute of a custom Device Handler so other apps can access the attribute

SHM Mapper SmartApp.groovy

/**
 *  SHM Mapper
 *
 *  Copyright 2017 Josh Lyon
 *
 *  This SmartApp works in unison with the custom SHM Mapper device type handler to copy Smart Home Monitor statuses to an
 *  attribute of a Thing. Even though SHM code is available on the SmartThings community, it was never officially approved
 *  for use in officially published SmartApps. 
 *
 *  In order to get around this, the SHM Mapper SmartApp copies SHM status to the attribute of a Thing so that Thing can be 
 *  subscribed to in other official SmartApps. For example, you could use this to display SHM status in SharpTools.
 *
 *  Required Device Type Handler: https://gist.github.com/joshualyon/22f6e8f7bebd37779e50f5e42d8cc761
 */
definition(
    name: "SHM Mapper",
    namespace: "joshualyon",
    author: "Josh Lyon",
    description: "Maps Smart Home Monitor states to a device attribute for access in other applications",
    category: "My Apps",
    iconUrl: "https://s3.amazonaws.com/smartapp-icons/Convenience/Cat-Convenience.png",
    iconX2Url: "https://s3.amazonaws.com/smartapp-icons/Convenience/[email protected]",
    iconX3Url: "https://s3.amazonaws.com/smartapp-icons/Convenience/[email protected]")


preferences {
	section("Select your custom SHM Mapper device"){
        paragraph "Note that all Alarm devices are shown. Select the installed SHM Mapper device."
        input "shmDevice", "capability.alarm", title: "Which SHM Mapper?"
    }
    section("Other Settings")
}

def installed() {
	log.debug "Installed with settings: ${settings}"

	initialize()
}

def updated() {
	log.debug "Updated with settings: ${settings}"

	unsubscribe()
	initialize()
}

def initialize() {
	//subscribe to attributes, devices, locations, etc.
    //Subscribe to SHM status
    subscribe(location, "alarmSystemStatus", alarmStatusHandler)
}

def alarmStatusHandler(evt) {
    log.debug "alarm status changed to: ${evt.value}"
    shmDevice.setShmState(evt.value)
    log.debug "SHM mapped device is now: ${shmDevice.currentValue("shmState")}"
}