メッセージをコンテキストの値によってルーティングする
課題
フローコンテキストの現在の値によって、メッセージをルーティングしたい。
解決
Switch ノードを使用して、
さまざまな入力を異なる出力に対応させるようフローコンテキストのプロパティ値をチェックします。
例
[{"id":"a62d8cdf.1bd82","type":"inject","z":"ac14500e.2c57d","name":"Inject","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":110,"y":600,"wires":[["b8bbbc41.f272"]]},{"id":"b8bbbc41.f272","type":"switch","z":"ac14500e.2c57d","name":"Context based routing","property":"state","propertyType":"flow","rules":[{"t":"eq","v":"1","vt":"num"},{"t":"eq","v":"2","vt":"num"},{"t":"eq","v":"3","vt":"num"}],"checkall":"true","repair":false,"outputs":3,"x":320,"y":600,"wires":[["9aa9c6b2.18a8e8"],["6ba4ec46.476794"],["a2e806c8.ffa168"]]},{"id":"9aa9c6b2.18a8e8","type":"debug","z":"ac14500e.2c57d","name":"Output 1","active":true,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","x":560,"y":540,"wires":[]},{"id":"6ba4ec46.476794","type":"debug","z":"ac14500e.2c57d","name":"Output 2","active":true,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","x":560,"y":600,"wires":[]},{"id":"a2e806c8.ffa168","type":"debug","z":"ac14500e.2c57d","name":"Output 3","active":true,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","x":560,"y":660,"wires":[]},{"id":"8aabdb51.e8b538","type":"inject","z":"ac14500e.2c57d","name":"Set state 0","topic":"","payload":"0","payloadType":"num","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":120,"y":680,"wires":[["e46083e4.1f17b"]]},{"id":"d1722dee.48db4","type":"inject","z":"ac14500e.2c57d","name":"Set state 1","topic":"","payload":"1","payloadType":"num","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":120,"y":720,"wires":[["e46083e4.1f17b"]]},{"id":"4bdb08de.706328","type":"inject","z":"ac14500e.2c57d","name":"Set state 2","topic":"","payload":"2","payloadType":"num","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":120,"y":760,"wires":[["e46083e4.1f17b"]]},{"id":"220ce0a6.cf81e","type":"inject","z":"ac14500e.2c57d","name":"Set state 3","topic":"","payload":"3","payloadType":"num","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":120,"y":800,"wires":[["e46083e4.1f17b"]]},{"id":"e46083e4.1f17b","type":"change","z":"ac14500e.2c57d","name":"Set flow.state","rules":[{"t":"set","p":"state","pt":"flow","to":"payload","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":340,"y":720,"wires":[[]]}]
議論
この例において、上のフローは Switch ノードによって、
3つの出力うちの1つにルーティングされる必要があるメッセージのストリームを表しています。
下のフローでは、コンテキストプロパティの flow.state へ値をセットするための
Inject ノードです。
これは、1つのフロー内のルーティングが、どのように他のフローによって変更されるかを示しています。