isItemStateChanged

These events arise when the value of the item has changed from one corresponding to the start value to one corresponding to the finish value.
When the expected transition of the item value happens, the event switches its state to True and then instantly switches back to False.
The event supports expressions. Expressions may be used for start and/or finish values.
Change of the value of an expression doesn’t make the event re-check if the item’s value satisfies event’s parameters, ergo change in expression cannot cause triggering the event.
The event may be used to check if any of those transitions happened:

any -> any — event is triggered for any change of the item value.
any -> value — event is triggered when the item value becomes equal to the specified value regardless of its previous value.
value -> any — event is triggered when the item value was equal to the specified value before the change.
value1 -> value2 — event is triggered when the item value transits from one specified value to another. A reaction is started when the item value becomes equal to the start value and finishes when it becomes equal to the finish value, no matter how long and how many steps it takes.

This feature is available since advanced_scenes/1.30.

Edit

Field	Type	Required	Description
blockOptions.method.args.item blockOptions.method.args.expression	item expression	+	Id of an item or expression whose value to check.
blockOptions.method.args.start	[any]	–	The value from which item should transit to another value to trigger the event conditions check. May be a certain value or “any”. Optional, default is “any”.
blockOptions.method.args.finish	[any]	–	The value, transition to which will trigger the event conditions check. May be a certain value or “any”. Optional, default is “any”.

Edit

Internal error code	Message	Data
SCENE_WRONG_WHEN_BLOCK	isItemStateChanged: empty id of an item	ezlo.scenes.block.when.wrong
SCENE_WRONG_WHEN_BLOCK	isItemStateChanged: cannot create valid ‘start’ value: [REASON]	ezlo.scenes.block.when.wrong
SCENE_WRONG_WHEN_BLOCK	isItemStateChanged: cannot create valid ‘finish’ value: [REASON]	ezlo.scenes.block.when.wrong
SCENE_WRONG_WHEN_BLOCK	isItemStateChanged: ‘start’ is incomparable with old value of the item ([START VALUE TYPE] – [ITEM VALUE TYPE])	scenes.when.type.mismatch
SCENE_WRONG_WHEN_BLOCK	isItemStateChanged: ‘start’ is incomparable with new value of the item ([START VALUE TYPE] – [ITEM VALUE TYPE])	scenes.when.type.mismatch
SCENE_WRONG_WHEN_BLOCK	isItemStateChanged: ‘finish’ is incomparable with new value of the item ([FINISH VALUE TYPE] – [ITEM VALUE TYPE])	scenes.when.type.mismatch

Edit

				
					{
    "blockType":"when",
    "blockOptions":{
        "method":{
            "name":"isItemStateChanged",
            "args":{
                "item":"item",
                "start": "start",
                "finish": "finish"
            }
        }
    },
    "fields":[
        {
            "name":"item",
            "type":"item",
            "value":"897607_32771_1"
        },
        {
            "name":"start",
            "type":"int",
            "value":10
        },
        {
            "name":"finish",
            "type":"expression",
            "value":"my_best_expression"
        }
    ]
}