This flow creates a simple in memory queue of incoming messages, and uses a feedback from a following action to release the next message.
In this example the message calls the say TTS command, which reads out the incoming message. Without the queue multiple inputs will get spoken over the top of each other.
Say is a text to speech command line app for Mac.
For Llnux or Raspberry Pi - try replacing the say command in the exec node with espeak .
| [{"id":"8bb0eecc.744f1","type":"exec","z":"9e538f88.61ac7","command":"say","addpay":true,"append":"","useSpawn":false,"name":"","x":589,"y":587,"wires":[["23263896.dcd9c8","e872b22f.178d5"],[],[]]},{"id":"23263896.dcd9c8","type":"debug","z":"9e538f88.61ac7","name":"","active":true,"console":"false","complete":"false","x":815,"y":576,"wires":[]},{"id":"c503216.f3afce","type":"inject","z":"9e538f88.61ac7","name":"","topic":"","payload":"\"Isn't it nice to have a computer that will talk to you?\"","payloadType":"string","repeat":"","crontab":"","once":false,"x":149,"y":587,"wires":[["8d68ad.ff72975"]]},{"id":"8d68ad.ff72975","type":"function","z":"9e538f88.61ac7","name":"Simple triggered queue","func":"// if queue doesn't exist, create it\ncontext.queue = context.queue || [];\ncontext.busy = context.busy || false;\n\n// if the msg is a trigger one release next message\nif (msg.hasOwnProperty(\"trigger\")) {\n if (context.queue.length > 0) {\n var m = context.queue.shift();\n return {payload:m};\n }\n else {\n context.busy = false;\n }\n}\nelse {\n if (context.busy) {\n // if busy add to queue\n context.queue.push(msg.payload);\n }\n else {\n // otherwise we are empty so just pass through and set busy flag\n context.busy = true;\n return msg;\n }\n}\n\nreturn null;","outputs":1,"noerr":0,"x":374,"y":586,"wires":[["8bb0eecc.744f1"]]},{"id":"e872b22f.178d5","type":"function","z":"9e538f88.61ac7","name":"set trigger","func":"// handle the return from the exec in here \n// if all is good then set msg.trigger property to exist\nmsg.trigger = 1;\nreturn msg;","outputs":1,"noerr":0,"x":654,"y":740,"wires":[["8d68ad.ff72975"]]}] |
Very interesting way to queue messages. Would you mind if I transform your code and create a contrib node? 😄