# Reading onoff property with Homeyscript

**URL:** https://community.homey.app/t/reading-onoff-property-with-homeyscript/44800
**Category:** Questions & Help
**Tags:** homeyscript
**Created:** [March 17, 2021, 11:48am UTC](https://community.homey.app/t/reading-onoff-property-with-homeyscript/44800 "2021-03-17T11:48:13Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![AlexP](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/alexp/32/36544_2.png) [@AlexP](https://community.homey.app/u/AlexP)
#### Post date: [March 17, 2021, 11:48am UTC](https://community.homey.app/t/reading-onoff-property-with-homeyscript/44800/1 "2021-03-17T11:48:13Z")

</div>

Hi,

I’m trying to create my first homeyscript. I do have experience in programming but not in JavaScript, and I can’t wrap my head around this, in my opinion, very simple problem.

I have this Hue light, and I want to make a script that switches the light on when it’s off, and vice versa.

The switching on/off part is working, but getting the current state is the problem.

This is what I have:

```
let LightID = '1d81d3cd-f3ec-4025-8210-4cb930004577';

var MyLight = await Homey.devices.getDevice({ id: LightID });

await MyLight.setCapabilityValue('onoff', true);

```

I tried to read the onoff property in different ways (I found browsing scripts on this forum), but all below are not working (“is not a function” error):

```
MyLight.CapabilitiesObj.onoff.value
MyLight.getCapabilityValue('onoff')
MyLight.state.onoff

```

If anybody can help me get on my way, I’d most appreciate it!

---

<div class="post-metadata">

### Author: ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)
#### Post date: [March 17, 2021, 12:10pm UTC](https://community.homey.app/t/reading-onoff-property-with-homeyscript/44800/2 "2021-03-17T12:10:17Z")

</div>

`MyLight.capabilitiesObj.onoff.value`

However, this is a lazily updated value, which means that you cannot change the state _and_ retrieve it from the same script and expect the retrieved state to match the changed state. The other way around should work: retrieve it (for instance to check if it’s already on or off), then change it (using `setCapabilityValue`).

---

<div class="post-metadata">

### Author: ![AlexP](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/alexp/32/36544_2.png) [@AlexP](https://community.homey.app/u/AlexP)
#### Post date: [March 17, 2021, 12:47pm UTC](https://community.homey.app/t/reading-onoff-property-with-homeyscript/44800/3 "2021-03-17T12:47:44Z")

</div>

Thanks for the help, this is now working.

I did try something like this before but got an error. Maybe I got the error on some other part of the script.

I noticed the “lazy” part. Checking too soon after setting the value, indeed results in the wrong value.

So this is wat the script now looks like now (for future reference).

```
let LightID = '1d81d3cd-f3ec-4025-8210-4cb930004577';

var MyLight = await Homey.devices.getDevice({ id: LightID });

if (MyLight.capabilitiesObj.onoff.value) {
    await MyLight.setCapabilityValue('onoff', false);
} else {
    await MyLight.setCapabilityValue('onoff', true);
}
```