node-red/packages/node_modules/@node-red/nodes/examples/function/function/10 - Asynchronous setup.json

[{"id":"89904b80.4fcd08","type":"inject","z":"d44bc7c8.48eca8","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":true,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":190,"y":100,"wires":[["22c235a0.acb41a"]]},{"id":"20fa70dc.7107f","type":"debug","z":"d44bc7c8.48eca8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":550,"y":100,"wires":[]},{"id":"cddf88c9.9df018","type":"comment","z":"d44bc7c8.48eca8","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":150,"y":40,"wires":[]},{"id":"22c235a0.acb41a","type":"function","z":"d44bc7c8.48eca8","name":"async. setup","func":"// retrieve message value\nmsg.payload = global.get('message');\nreturn msg;","outputs":1,"noerr":0,"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":"","x":370,"y":100,"wires":[["20fa70dc.7107f"]]}]