sendCommand and itemName from variable

[omadon]

This is working:

sendCommand(myIphone,OPEN)

and this is not:

var String myItem = "myIphone"
sendCommand(myItem,OPEN)

Why?

[lipp_markus]

Assuming that you defined an item “myIphone” somewhere in your .items file, in the first case you make reference to an object (items are specific objects that are defined in eclipse; these objects have other structures and methods attached to it) in the second to a string (which, granted, is an object too in java, but for all intends and purposes of this discussion, it is just a string of letters with nothing else to it).

Simply put:
an item myIphone “knows” (through methods) what a command is, how to send a command, and what it needs to do with such a command, etc; a string does not

[omadon]

Ok, but how do I get reference to item object based on the item name.

[lipp_markus]

It is not really clear to me where you want to go with it, but if you want a way to make a more generic rule, you might be interested to read up on how to trigger behaviors over rules using groups:

Design Pattern: Working with Groups in Rules

Edit: Updates for OH 4, inclusion of JS Scripting and Blockly examples, removed the doors example as it’s superfluous. Please see Design Pattern: What is a Design Pattern and How Do I Use Them for how to read and use DPs. Problem Statement One powerful way to consolidate code in rules is to use array/list manipulation operations on the members of a Group. For example, filter down to just those members that are ON, get a list of the labels of those Items that are NULL, etc. Concept [image] T…

[Deprecated] Design Patterns: Generic Is Alive

There is now a Rule Template on the marketplace to implement this for you. See below for instructions on how to set it up. Please see Design Pattern: What is a Design Pattern and How Do I Use Them for a description of what Design Patterns are and how to use them. Problem Statement Many sensors report status to openHAB periodically (e.g. temperature sensor) or unpredictably (e.g. motion sensors) and a subset of these sensors do not have a built in way for openHAB to query whether or not they a…

[omadon]

I have very simple rule that is monitoring list of bluetooth addresses. I’m trying to get this to work:

/ Detect bluetooth devices every minute
// chmod 4755 /usr/bin/l2ping

import java.util.HashMap

rule "Detect BT device"
    when
        Time cron "0 0/1 * * * ?"
    then
        var String output1

        val HashMap<String,String> devices = new HashMap<String, String>()
        devices.put("omadon_iphone5s", "1C:1A:C0:1D:46:9F")
        devices.put("j_phone",  "5C:2E:59:1F:C2:04")

        for (String key : devices.keySet() ) {
            output1 = executeCommandLine("/usr/bin/l2ping -c1 "+devices.get(key), 3000)
            if (output1.contains("received")) {
                sendCommand(key,OPEN)
                logInfo("SYSTEM", "BT device "+devices.get(key)+": Found!!!")
            }
            else {
                sendCommand(key,CLOSED)
                logInfo("SYSTEM", "BT device "+devices.get(key)+": Not found!!!")
            }
        }
end

And here sendCommand fails:

Error during the execution of rule Detect BT device: An error occured during the script execution: Could not invoke method: org.eclipse.smarthome.model.script.actions.BusEvent.sendCommand(java.lang.String,java.lang.String) on instance: null

[lipp_markus]

Sory, will not be able to comment much, but still unclear what you want to achieve:
it appears the sendCommand is identical in both branches of the if statement, also not sure whether OPEN is supported, you may have to check your time definitions (depends on the item)
Unless you want to add many more items, your rule seems to have a lot of overhead for two devices.

Not that I would know how to code this, but I am sure there is a way to add your items to the hashmap and then you could get retrieve the instance of the item that sendCommand needs, rather than the string with the name

Last thought, on other posts on this forum, it is recommended to use rather:
item.sendCommand(Command) as it appears more reliable than the more generic method: sendCommand(item, Command)

[omadon]

Copy paste error. It is fixed now. The idea is to have hashmap containing item and mac address. Based on ping result I want to trigger switch item to OPEN or CLOSED. The problem is if I pass itemName as a string to the sendCommand this is not working because probably in this case he will try to set item named “key” and not the current value of “key”.

[lipp_markus]

I believe you are right, it looks to me that you need to find a way where you can actually pass a reference to the relevant instance of the object (item) to the line item.sendCommand(Command); a string is only a string and would not point to your object.
Even if it did work, it looks to me that the value of key is either “omadon_iphone5s” or “j_phone” to either you then want to send an open or closed command. You may need to doublecheck this, but I thought switches take ON and OFF as commands.

[omadon]

I used your advice about Working with groups in rules and rewrited my rule. Now it is working fine, but I would still like to know how to reference to item object without iterating over group members.

/etc/openhab2/items/switch.items:

Group gMobiles
Group gBTdevices
Contact         omadon_iphone5s         "1C:1A:C0:1D:46:9F"     <apple>         (gMobiles, gBTdevices)
Contact         j_phone                 "5C:2E:59:1F:C2:04"     <android>       (gMobiles, gBTdevices)

/etc/openhab2/rules/detect_bt.rules:

// Detect bluetooth devices every minute
// chmod 4755 /usr/bin/l2ping
// log:set DEBUG org.eclipse.smarthome.model.script.BT

rule "Detect BT device"
    when
        Time cron "0 0/1 * * * ?"
    then
        var String output

        gBTdevices.members.forEach[ i | {
            output = executeCommandLine("/usr/bin/l2ping -c1 "+i.label, 3000)
            if (output.contains("received")) {
                i.postUpdate(OPEN)
                logDebug("BT", "BT device "+i.name+" ["+i.label+"]  Found.")
            }
            else {
                i.postUpdate(CLOSED)
                logDebug("BT", "BT device "+i.name+" ["+i.label+"]  Not found!!!")

            }

            }
        ]
end

[lipp_markus]

Glad you got it to work,
As for your remaining question, maybe this post helps you a little further:

Configurable scenarios

For who want to have ability to adjust configuration of scenarios in “runtime”, from the app, here you will find a working example of it. This is a stand-alone example, you have obviously to modify something to integrate it in your system. First of all, light items, for example lights.items. // LIGHTS ITEMS & GROUPS Group gLights Switch Room1_Light01 "Light 01" (gLights) Dimmer Room2_Light02 "Light 02" (gLights) Switch Room3_Light03 "Light 03 RGB" (gLights) Color Room…

[rossko57]

As a generalism, sending commands to Contact items makes little sense. You would normally use postUpdate.

[omadon]

You are right, fixed…