Check for null in widget yaml

proggprod commented 2 years ago

The problem

Can not check for NULL in widget yaml.

When creating dynamic / intelligent widgets that interact with a range of similar items it should be possible to check for NULL without throwing an error in the log. eg a light control widget that responds slightly differently depending on whether the light in question is a switch on/off only, dimmable, CCT, RGB, some with motion sensors, some with motion sensors and light sensors.

I have 13 lights, a combination of different types, and when I load the page with 13 widgets there is a significant delay while all these errors happen, then everything functions as normally, except for the dirty log.

I started a discussion on the forum about this https://community.openhab.org/t/widget-check-if-item-exists/134910/10

Your suggestion

It should be possible to check for a null by coding something like this in widget yaml visible: '=(items[props.lightItem + "_Brightness"].state != null) ? true: false'

if the item Hall_Light is the light in question, it will look for Hall_Light_Brightness (to check if it is a dimmable light), if it doesn't exist, it should not throw an error to the log.

Your environment

runtimeInfo:
  version: 3.3.0.M4
  buildString: Milestone Build
locale: en-IE
systemInfo:
  configFolder: /openhab/conf
  userdataFolder: /openhab/userdata
  logFolder: /openhab/userdata/logs
  javaVersion: 11.0.15
  javaVendor: Azul Systems, Inc.
  javaVendorVersion: Zulu11.56+19-CA
  osName: Linux
  osVersion: 5.15.32-v8+
  osArchitecture: aarch64
  availableProcessors: 4
  freeMemory: 69687920
  totalMemory: 405798912
  startLevel: 70
bindings:
  - deconz
  - icalendar
  - icloud
  - lifx
  - network
  - openweathermap
  - samsungtv
  - shelly
  - sonoff
  - sonos
  - tado
clientInfo:
  device:
    ios: false
    android: false
    androidChrome: false
    desktop: true
    iphone: false
    ipod: false
    ipad: false
    edge: false
    ie: false
    firefox: false
    macos: false
    windows: true
    cordova: false
    phonegap: false
    electron: false
    nwjs: false
    webView: false
    webview: false
    standalone: false
    os: windows
    pixelRatio: 1.3300000429153442
    prefersColorScheme: dark
  isSecureContext: false
  locationbarVisible: true
  menubarVisible: true
  navigator:
    cookieEnabled: true
    deviceMemory: N/A
    hardwareConcurrency: 2
    language: en
    languages:
      - en
      - en-US
    onLine: true
    platform: Win32
  screen:
    width: 3850
    height: 1083
    colorDepth: 24
  support:
    touch: false
    pointerEvents: true
    observer: true
    passiveListener: true
    gestures: false
    intersectionObserver: true
  themeOptions:
    dark: dark
    filled: true
    pageTransitionAnimation: default
    bars: light
    homeNavbar: default
    homeBackground: standard
    expandableCardAnimation: default
  userAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.67 Safari/537.36
timestamp: 2022-05-25T07:59:04.548Z

Additional information

ghys commented 2 years ago

Similar to https://github.com/openhab/openhab-core/issues/2000. I would argue the severity of this log message should be lowered to DEBUG maybe.

petero-dk commented 1 year ago

+1

I have the same issue, an oh-repeater that lists the different lights, some as switches, some with dimming channels, some with colortemp etc. They are strickly named so the widget checks for existence via naming conventions.

openhab / openhab-webui