# node-red-contrib-dsm A dynamic state machine node based on the [Finite state machine](https://en.wikipedia.org/wiki/Finite-state_machine) model. The `dsm` node is a pure Node.js package for Node Red, it doesn't use any external libraries. The dsm behaviour is defined in a JSON format and can be optianally set/modified programmatically e.g. using an inject node. #### Principle of operation [Wikipedia] *A finite-state machine (FSM) is an abstract machine that can be in exactly one of a finite number of states at any given time. The FSM can change from one state to another in response to some external inputs; the change from one state to another is called a transition. A FSM is defined by a list of its states, its initial state, and the conditions for each transition.* ## Usage The `dsm` properties can be defined in the `edit dsm node` window or by an input JSON object: ![dsmconf](https://user-images.githubusercontent.com/5056710/42732001-ca361a6e-8818-11e8-8b24-c121ddbda784.jpeg) #### JSON object: ``` topic: "set" payload: { "triggerInput": "topic", "stateOutput": "current", "preStateOutput": "previous", "globalOutput": "my_global_var", "flowOutput": "my_flow_var", "preState": null, "currentState": "state1", "states": { "state1": { "transition2": "state2" }, "state2": { "transition1": "state1", "transition3": "state3" }, "state3": { "transition1": "state1", "transition2": "state2" } } } ``` `triggerInput`, `stateOutput`, `preStateOutput`, `globalOutput` and `flowOutput` can be omitted. `triggerInput` and `stateOutput` default `topic`. `preStateOutput` default `preState` `globalOutput` and `flowOutput` default `false`. If `globalOutput` or `flowlOutput` is defined, the corresponding variable is additionally set. When the node receives a trigger with a transition it will change from one state to another: ``` topic: "transition" payload: any ``` ### Data and methods In addition to states and transitions a `dsm` can also contain arbitrary data and methods. #### Example: ``` { "stateOutput": "payload", "currentState": "one_state", "states": { "recursive": "one_state" }, "data": { "delay": 2000 }, "methods": { "setDelay": "sm.data.delay = msg.payload;", "getDelay": "msg.delay = sm.data.delay;", "default": "msg.payload = 'method undefined'" } } ``` Methods can be any valid javascript statements. If the method name is the same as the transition name, both the transition and the method are processed. The method `default` is executed when no method is found in the methods list. To simplify editing methods can be defined as an array of comma separated strings: ``` "onTransition" : [ "if (sm.data.indoor > sm.data.outdoor) {", "msg.payload = 'indoor > outdoor';", "} else if (sm.data.indoor < sm.data.outdoor) {", "msg.payload = 'indoor < outdoor';", "} else {", "msg.payload = 'indoor = outdoor';", "}" ] ``` ### General purpose methods * `init` * `onBeforeTransition` * `onTransition` * `onAfterTransition` * `status` defines an arbitrary status The general purpose methods are executed independently even without states. The `init` method is executed when the dsm is deployed respectively when the dsm is set. `init` can be used to initialize values. #### Example: ``` } "methods": { "onTransition": "msg.payload = {'sid': global.get('xiaomi_name')[msg.payload]};", "status": { "fill": "green", "shape": "ring", "text": { "get": "JSON.stringify(msg.payload)" } } } } ``` ### Build-in methods To simplify the configuration build-in methods are available. * setData * getData * timer * resetTimer * watchdog ### Configuration Examples #### setData and getData ``` { "data": { "temperature": 0, "humidity": 0, "pressure": 0, "co2": 0 }, "methods": { "temperature": { "name": "setData" }, "humidity": { "name": "setData" }, "pressure": { "name": "setData" }, "co2": { "name": "setData" }, "getData": { "name": "getData" } } } ``` #### timer and watchdog ``` { "data": { "delay1": 2000, "delay2": 3000 }, "methods": { "timer1": { "name": "timer", "param": "delay1" }, "timer2": { "name": "timer", "param": "delay2", "do": "node.status({});" }, "timer3": { "name": "timer", "param": 5000, "send": "toilet window timeout" }, "resetTimer3": { "name": "resetTimer", "param": "timer3" }, "watchdog1": { "name": "watchdog", "param": 5000, "send": { "get": "msg.payload.name+' timeout';" } } } } ``` `timer`and `watchdog` param in milliseconds. `do` executes a statement. `send` sets msg.payload - either to a string or when using `get` to the result of a statement - and send the msg. ## Examples ### Door ![door-7 2](https://user-images.githubusercontent.com/5056710/43066264-7c5db476-8e64-11e8-8a7f-076ca58d4d19.png) #### Configuration ``` { "currentState": "closed", "states": { "opened": { "close": "closed", "stop": "stopped" }, "closed": { "open": "opened", "stop": "stopped" }, "stopped": { "open": "opened", "close": "closed" } } } ``` #### Flow ``` [{"id":"8b02669f.7ddd98","type":"debug","z":"57ef434a.058a6c","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","x":430,"y":1680,"wires":[]},{"id":"68c0e2d5.3b798c","type":"inject","z":"57ef434a.058a6c","name":"open","topic":"open","payload":"your open payload","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":90,"y":1640,"wires":[["3b0c292.2da33d6"]]},{"id":"fae17b11.e48a88","type":"inject","z":"57ef434a.058a6c","name":"close","topic":"close","payload":"your close payload","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":90,"y":1680,"wires":[["3b0c292.2da33d6"]]},{"id":"3b0c292.2da33d6","type":"dsm","z":"57ef434a.058a6c","name":"door","sm_config":"{\n \"currentState\": \"closed\",\n \"states\": {\n \"opened\": {\n \"close\": \"closed\",\n \"stop\": \"stopped\"\n },\n \"closed\": {\n \"open\": \"opened\",\n \"stop\": \"stopped\"\n },\n \"stopped\": {\n \"open\": \"opened\",\n \"close\": \"closed\"\n }\n }\n}","x":260,"y":1680,"wires":[["8b02669f.7ddd98"]]},{"id":"caac460e.2942c8","type":"inject","z":"57ef434a.058a6c","name":"stop","topic":"stop","payload":"your stop payload","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":90,"y":1720,"wires":[["3b0c292.2da33d6"]]}] ``` ### Garage door ![garade_door-7 2](https://user-images.githubusercontent.com/5056710/43066538-3bfcdd2a-8e65-11e8-97d2-13d7b298c473.png) #### Configuration ``` { "stateOutput": "payload", "currentState": "closed", "states": { "opened": { "click": "closing" }, "closed": { "click": "opening" }, "opening": { "limit_switch": "opened", "click": "opening_stopped" }, "closing": { "limit_switch": "closed", "click": "closing_stopped" }, "opening_stopped": { "click": "closing" }, "closing_stopped": { "click": "opening" } } } ``` #### Flow ``` [{"id":"1501e603.fdbeba","type":"dsm","z":"57ef434a.058a6c","name":"garage door","sm_config":"{\n \"stateOutput\": \"payload\",\n \"globalOutput\": \"garage_door_state\",\n \"currentState\": \"closed\",\n \"states\": {\n \"opened\": {\n \"click\": \"closing\"\n },\n \"closed\": {\n \"click\": \"opening\"\n },\n \"opening\": {\n \"limit_switch\": \"opened\",\n \"click\": \"opening_stopped\"\n },\n \"closing\": {\n \"limit_switch\": \"closed\",\n \"click\": \"closing_stopped\"\n },\n \"opening_stopped\": {\n \"click\": \"closing\"\n },\n \"closing_stopped\": {\n \"click\": \"opening\"\n }\n }\n}","x":260,"y":1240,"wires":[["2125cea7.329542"]]},{"id":"4744a8a3.28aec8","type":"inject","z":"57ef434a.058a6c","name":"click","topic":"click","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":90,"y":1240,"wires":[["1501e603.fdbeba"]]},{"id":"379cd28e.34076e","type":"link in","z":"57ef434a.058a6c","name":"to timer","links":["4c183a20.342304"],"x":115,"y":1280,"wires":[["1501e603.fdbeba"]]},{"id":"4c183a20.342304","type":"link out","z":"57ef434a.058a6c","name":"from dsm","links":["379cd28e.34076e"],"x":535,"y":1340,"wires":[]},{"id":"5a467385.1c0bcc","type":"comment","z":"57ef434a.058a6c","name":"motor simulation","info":"","x":440,"y":1200,"wires":[]},{"id":"2125cea7.329542","type":"change","z":"57ef434a.058a6c","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"payload = \"opening\" or payload = \"closing\" ? payload : \"reset\"","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":440,"y":1240,"wires":[["23d5eb3e.3f4fa4"]]},{"id":"23d5eb3e.3f4fa4","type":"trigger","z":"57ef434a.058a6c","op1":"","op2":"limit_switch","op1type":"nul","op2type":"str","duration":"3","extend":false,"units":"s","reset":"reset","bytopic":"topic","name":"","x":320,"y":1340,"wires":[["77a5a197.e301e"]]},{"id":"77a5a197.e301e","type":"change","z":"57ef434a.058a6c","name":"topic","rules":[{"t":"set","p":"topic","pt":"msg","to":"payload","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":450,"y":1340,"wires":[["4c183a20.342304"]]}] ``` For more examples have a look at the [Wiki](https://github.com/cflurin/node-red-contrib-dsm/wiki)