sendCmd to Contact doesnt work

I’m trying to build a widget for my Nuki locks, showing lock and battery status and also allowing to lock/unlock the doors. I had everything working already using a Switch item for the lock but then decided to change to a Contact item instead, and i cant get it to work.

this is my items file:

Number  EGFrontdoorLockStatus           { http="<[http://EGTec1NukiBridge:8080/list?token=xxx:30000:JSONPATH($[0].lastKnownState.state)]"}
Contact EGFrontdoorLock         <lock>  { http=">[CLOSE:GET:http://EGTec1NukiBridge:8080/lockaction?token=xxx&nukiid=yyy&action=2] >[OPEN:GET:http://EGTec1NukiBridge:8080/lockaction?token=xxx&nukiid=yyy&action=1]"}
String  EGFrontdoorLockBatteryCritical  { http="<[http://EGTec1NukiBridge:8080/list?token=xxx:30000:JSONPATH($[0].lastKnownState.batteryCritical)]"

and this is the rules file:

rule "Nuki EGFrontdoorLock"
        Item EGFrontdoorLockStatus changed
        if (EGFrontdoorLockStatus.state == 1) {
        } else {

This part is working fine - So when i lock/unlock the door using the Nuki app, the EGFrontdoorLockStatus is set to either 1 or 3, after a while the rule is triggered and the EGFrontdoorLock changes to CLOSED or OPEN.

this is the part of the widget which is supposed to build the button and trigger action:

  <div ng-if="itemValue(config.ITEM_ID) =='CLOSED'">
    <button class="btn btn-lg" style="background: transparent; color: white"
            ng-click="sendCmd(config.ITEM_ID, 'OPEN')">
  <div ng-if="itemValue(config.ITEM_ID) =='OPEN'">
    <button class="btn btn-lg" style="background: red; color: white"
            ng-click="sendCmd(config.ITEM_ID, 'CLOSE')">

it is shown nice & correct in my habpanel

but when I trigger the button I get the following messages in openhab.log:

16:31:42.681 [WARN ] [] - Received HTTP POST request at 'items/EGFrontdoorLock' with an invalid status value 'CLOSE'.
16:32:24.273 [WARN ] [] - Received HTTP POST request at 'items/EGFrontdoorLock' with an invalid status value 'OPEN'.

To me this seems as if Contacts are not supposed to receive commands ? Or am I doing something wrong here ? I’ve tried CLOSED, OPENCLOSE, several other things with slightly different behaviour, but at the end none of them works…

Contacts are indeed not supposed to receive commands. Switches are intended for this use. Contacts are to represent a binary sensor. Switches represent a binary actuator.

thx Rick - When i stumbled across this i thought so, however documentation was a bit misleading to me:

Here it states OpenClose as CommandTypes for Contacts - shouldnt this table be changed somehow to reflect what exactly can be done with sendCmd and postUpdate for each item type ?

Correction - After thinking about it a bit, to me item types should not differentiate between sensors or actuators, there should be no such restriction. What is the rational behind this ?

I don’t know for sure but I think it comes down to the default behavior of the Item when it is put on the sitemap. If we only had one type for what amounts to a boolean, you would end up with a case where a Switch would by default show up without a toggle or a Contact would show up with a Toggle.

Unfortunately Switches and Contacts are not used consistently by the bindings so a lot of devices which are sensors (motion sensors, door/window sensors, etc) end up mapped to Switches.

Because of this inconsistent treatment by the bindings I’m a bit ambivalent about having the two. I see the value in having a read only boolean on the sitemap (Contact) as well as a binary actuator (Switch) which can be properly represented by default, yet I’m uncomfortable with making this sort user interface distinction in a part of the config where IMHO it doesn’t belong.