⚡ Node-RED Functionノード ガイド

[ { "id": "98aa28d4a248e8cb", "type": "tab", "label": "function", "disabled": false, "info": "", "env": [] }, { "id": "ec5a531b.68b65", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "World", "payloadType": "str", "x": 290, "y": 140, "wires": [ [ "961abba6.04a028" ] ] }, { "id": "1b0f8c3e.1fd7e4", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 670, "y": 140, "wires": [] }, { "id": "4e5bf6b2.b4dd58", "type": "comment", "z": "98aa28d4a248e8cb", "name": "send a message to output port", "info": "Function node can be used to write JavaScript code to handle messages.\nThe input message can be referrenced by `msg` variable. \nA message returned from body of the function is sent to output port.\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions).", "x": 310, "y": 80, "wires": [] }, { "id": "961abba6.04a028", "type": "function", "z": "98aa28d4a248e8cb", "name": "return a message", "func": "// returning message send it to output port\nmsg.payload = \"Hello, \"+msg.payload +\"!\";\nreturn msg;", "outputs": 1, "timeout": "", "initialize": "", "finalize": "", "libs": [], "x": 470, "y": 140, "wires": [ [ "1b0f8c3e.1fd7e4" ] ] }, { "id": "c2b3b0f1.62189", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "", "payloadType": "date", "x": 300, "y": 280, "wires": [ [ "7241db1e.8946c4" ] ] }, { "id": "c6191361.0f3c", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 730, "y": 260, "wires": [] }, { "id": "3aa5727c.e5019e", "type": "comment", "z": "98aa28d4a248e8cb", "name": "send multiple message", "info": "Function node can send multiple messages to output ports by returning an array of messages. \n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions).", "x": 280, "y": 220, "wires": [] }, { "id": "7241db1e.8946c4", "type": "function", "z": "98aa28d4a248e8cb", "name": "return array of messages", "func": "// returning array of message send elements to output ports\nvar msg1 = { payload:\"first out of output 1\" };\nvar msg2 = { payload:\"second out of output 1\" };\nvar msg3 = { payload:\"third out of output 1\" };\nvar msg4 = { payload:\"only message from output 2\" };\nreturn [ [ msg1, msg2, msg3 ], msg4 ];", "outputs": 2, "timeout": "", "initialize": "", "finalize": "", "libs": [], "x": 510, "y": 280, "wires": [ [ "c6191361.0f3c" ], [ "23a53d00.c89b74" ] ] }, { "id": "23a53d00.c89b74", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 730, "y": 300, "wires": [] }, { "id": "cc74476e.cbdf68", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "Hello, World!", "payloadType": "str", "x": 310, "y": 420, "wires": [ [ "7d90286.706e9d8" ] ] }, { "id": "909906c3.ea9f58", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 770, "y": 420, "wires": [] }, { "id": "d5fc0512.4cd9c8", "type": "comment", "z": "98aa28d4a248e8cb", "name": "sending messages asynchronously", "info": "Function node can asynchronously send a messages to output ports by calling `node.send` function.\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions).", "x": 320, "y": 360, "wires": [] }, { "id": "7d90286.706e9d8", "type": "function", "z": "98aa28d4a248e8cb", "name": "wait 2s then send message", "func": "// setTimeout calls calls specified callback function asynchronously after a specified time\nsetTimeout(function () {\n node.send(msg);\n}, 2*1000);\n", "outputs": 1, "timeout": "", "initialize": "", "finalize": "", "libs": [], "x": 540, "y": 420, "wires": [ [ "909906c3.ea9f58" ] ] }, { "id": "89c17d21.15da2", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "", "payloadType": "date", "x": 300, "y": 660, "wires": [ [ "1bcca7af.619428" ] ] }, { "id": "3b9cd70e.8e66e8", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 650, "y": 660, "wires": [] }, { "id": "f76ea68a.6f3c58", "type": "comment", "z": "98aa28d4a248e8cb", "name": "handling errors", "info": "Calling `node.error` function with the original message as a second argument, function node can trigger a catch node in the same tab.\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions).", "x": 260, "y": 600, "wires": [] }, { "id": "1bcca7af.619428", "type": "function", "z": "98aa28d4a248e8cb", "name": "report error", "func": "// In function node, calling node.error functions with the original input message as its second argument triggers catch node\n// See debug sidebar and console output\nnode.error(\"Oh no, something bad happened\", msg);\n// execution should stops here", "outputs": 1, "timeout": "", "initialize": "", "finalize": "", "libs": [], "x": 470, "y": 660, "wires": [ [ "3b9cd70e.8e66e8" ] ] }, { "id": "74854950.d99558", "type": "catch", "z": "98aa28d4a248e8cb", "name": "", "scope": [ "1bcca7af.619428" ], "uncaught": false, "x": 450, "y": 720, "wires": [ [ "32743f74.e718a" ] ] }, { "id": "32743f74.e718a", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "true", "targetType": "full", "statusVal": "", "statusType": "auto", "x": 630, "y": 720, "wires": [] }, { "id": "fb884166.e42f3", "type": "comment", "z": "98aa28d4a248e8cb", "name": "↑ error information can be found in msg.error", "info": "", "x": 750, "y": 760, "wires": [] }, { "id": "64470964.a291a8", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "", "payloadType": "date", "x": 300, "y": 540, "wires": [ [ "ee4f5964.5cdae8" ] ] }, { "id": "ed028c2f.924b", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 650, "y": 540, "wires": [] }, { "id": "b1686e70.a9f6d", "type": "comment", "z": "98aa28d4a248e8cb", "name": "logging events", "info": "In body of function node code, following logging functions can be used to log events:\n- `node.log`\n- `node.warn`\n- `node.error`\n- `node.trace`\n- `node.debug`\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions).", "x": 260, "y": 480, "wires": [] }, { "id": "ee4f5964.5cdae8", "type": "function", "z": "98aa28d4a248e8cb", "name": "log events", "func": "// In function node, node.log, node.warn, and node.error functions can be used for logging\n// See debug sidebar and console output\nnode.log(\"Something happened\");\nnode.warn(\"Something happened you should know about\");\nnode.error(\"Oh no, something bad happened\");\nreturn msg;", "outputs": 1, "timeout": "", "initialize": "", "finalize": "", "libs": [], "x": 470, "y": 540, "wires": [ [ "ed028c2f.924b" ] ] }, { "id": "a3a635eb.191188", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "", "payloadType": "date", "x": 300, "y": 860, "wires": [ [ "77f57d92.06fa14" ] ] }, { "id": "1a218bea.61ae04", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 630, "y": 860, "wires": [] }, { "id": "a56bde3a.330e1", "type": "comment", "z": "98aa28d4a248e8cb", "name": "storing data in context", "info": "The function node code can store data in the context store.\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions) and [context store](https://nodered.org/docs/user-guide/context).", "x": 280, "y": 800, "wires": [] }, { "id": "77f57d92.06fa14", "type": "function", "z": "98aa28d4a248e8cb", "name": "counter", "func": "// initialise the counter to 0 if it doesn't exist already\nvar count = context.get('count')||0;\ncount += 1;\n// store the value back\ncontext.set('count',count);\n// make it part of the outgoing msg object\nmsg.payload = count;\nreturn msg;", "outputs": 1, "timeout": "", "initialize": "", "finalize": "", "libs": [], "x": 460, "y": 860, "wires": [ [ "1a218bea.61ae04" ] ] }, { "id": "ce0b7cca.34817", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "red", "payloadType": "str", "x": 290, "y": 1000, "wires": [ [ "a4a6c205.8afd4" ] ] }, { "id": "c98c52d0.ab51f", "type": "comment", "z": "98aa28d4a248e8cb", "name": "showing status information", "info": "The function node code can provide status decoration by calling `node.status` function.\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions).", "x": 290, "y": 940, "wires": [] }, { "id": "a4a6c205.8afd4", "type": "function", "z": "98aa28d4a248e8cb", "name": "show status", "func": "// calling node.status show status information below the function node\nswitch (msg.payload) {\n case \"red\":\n node.status({fill:\"red\",shape:\"ring\",text:\"disconnected\"});\n break;\n case \"green\":\n node.status({fill:\"green\",shape:\"dot\",text:\"connected\"});\n break;\n case \"text\":\n node.status({text:\"Just text status\"});\n break;\n case \"clear\":\n node.status({}); // to clear the status \n break;\n}\n\n", "outputs": 0, "timeout": "", "initialize": "", "finalize": "", "libs": [], "x": 470, "y": 1000, "wires": [] }, { "id": "9f29ae74.8dd11", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "green", "payloadType": "str", "x": 290, "y": 1040, "wires": [ [ "a4a6c205.8afd4" ] ] }, { "id": "83fc1404.ec0b98", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "text", "payloadType": "str", "x": 290, "y": 1080, "wires": [ [ "a4a6c205.8afd4" ] ] }, { "id": "517a869c.0ceab8", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "clear", "payloadType": "str", "x": 290, "y": 1120, "wires": [ [ "a4a6c205.8afd4" ] ] }, { "id": "3ece1efd.306c22", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "", "payloadType": "date", "x": 380, "y": 1240, "wires": [ [ "c9100743.673598" ] ] }, { "id": "ed3da95d.62ee98", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 750, "y": 1240, "wires": [] }, { "id": "85b5b8ad.0717d8", "type": "comment", "z": "98aa28d4a248e8cb", "name": "using external modules (needs change in settings.js)", "info": "The function node can use external node modules using global context value.\n\nAdditional node modules must be loaded in `settings.js` file and added to the `functionGlobalContext` property. \n\nFor example, following definition in `settings.js` load `os` module on start up of Node-RED. \n\n```\nfunctionGlobalContext: {\n os: require(\"os\")\n}\n```\n\nThe `os` module can be accessed in a function blocks as:\n```\nglobal.get(\"os\")\n```\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions) and [context store](https://nodered.org/docs/user-guide/context).", "x": 520, "y": 1180, "wires": [] }, { "id": "c9100743.673598", "type": "function", "z": "98aa28d4a248e8cb", "name": "use os module", "func": "// use external os module to access OS information\nvar os = global.get(\"os\");\nmsg.payload = { \n hostname: os.hostname(),\n arch: os.arch(),\n platform: os.platform(),\n release: os.release(),\n free: os.freemem()\n};\nreturn msg;", "outputs": 1, "timeout": "", "initialize": "", "finalize": "", "libs": [], "x": 560, "y": 1240, "wires": [ [ "ed3da95d.62ee98" ] ] }, { "id": "e397736b.a96af", "type": "inject", "z": "98aa28d4a248e8cb", "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "topic": "", "payload": "", "payloadType": "date", "x": 300, "y": 1380, "wires": [ [ "900ad01c.561f" ] ] }, { "id": "1e2a78d6.33f617", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 630, "y": 1380, "wires": [] }, { "id": "83d3f2fd.593b4", "type": "comment", "z": "98aa28d4a248e8cb", "name": "setup and close", "info": "The function node code provide setup and closecode. \nThe `Setup` tab contains code that will be run whenever the node is started. The `Close` tab contains code that will be run when the node is stopped.\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions).", "x": 260, "y": 1320, "wires": [] }, { "id": "900ad01c.561f", "type": "function", "z": "98aa28d4a248e8cb", "name": "counter", "func": "// get value of global counter\nvar count = global.get('count');\ncount += 1;\n// store the value back\nglobal.set('count',count);\n// make it part of the outgoing msg object\nmsg.payload = count;\nreturn msg;\n", "outputs": 1, "timeout": "", "initialize": "// initialize global counter\nglobal.set('count', 0);", "finalize": "// report current counter to console\nvar count = global.get('count');\nconsole.log(\"count:\", count);", "libs": [], "x": 460, "y": 1380, "wires": [ [ "1e2a78d6.33f617" ] ] }, { "id": "89904b80.4fcd08", "type": "inject", "z": "98aa28d4a248e8cb", "d": true, "name": "", "props": [ { "p": "payload" }, { "p": "topic", "vt": "str" } ], "repeat": "", "crontab": "", "once": true, "onceDelay": 0.1, "topic": "", "payload": "", "payloadType": "date", "x": 310, "y": 1520, "wires": [ [ "22c235a0.acb41a" ] ] }, { "id": "20fa70dc.7107f", "type": "debug", "z": "98aa28d4a248e8cb", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "statusVal": "", "statusType": "auto", "x": 670, "y": 1520, "wires": [] }, { "id": "cddf88c9.9df018", "type": "comment", "z": "98aa28d4a248e8cb", "name": "asynchronous setup", "info": "The `Setup` code that performs asynchronous work can return a promise object of the work. The completion of the promise is waited before starting function body.\n\nSee Node-RED user guide about [functions](https://nodered.org/docs/user-guide/writing-functions).", "x": 270, "y": 1460, "wires": [] }, { "id": "22c235a0.acb41a", "type": "function", "z": "98aa28d4a248e8cb", "name": "async. setup", "func": "// retrieve message value\nmsg.payload = global.get('message');\nreturn msg;", "outputs": 1, "timeout": "", "initialize": "// set initial value of message\nglobal.set(\"message\", \"Initializing, World!\");\n// create promise for async work\nvar promise = new Promise((resolve, reject) => {\n // async work: wait 1s, then set message\n setTimeout(() => {\n global.set(\"message\", \"Hello, World!\");\n // report this work successfuly ended\n resolve();\n }, 1000);\n});\n// return the promise that should be executed before function code\nreturn promise;", "finalize": "", "libs": [], "x": 490, "y": 1520, "wires": [ [ "20fa70dc.7107f" ] ] } ]