Search code examples
node.jsnode-red

node-red wait for async query for http-response


I have REST-endpoint done with node-red which do some async tasks, for example odbc-query to the database.

When I'm resulting query to the http-response. It's just hangs on browser. Looks like I need forward req and res object to the http-response. But how I do it?

Here is the flow:

[{"id":"a35e6901.509a1","type":"http in","z":"ec714e97.d73b58","name":"","url":"/get","method":"get","upload":false,"swaggerDoc":"","x":287.8571472167969,"y":1660.357177734375,"wires":[["7c116e0a.f8d67"]]},{"id":"98e22918.79bc4","type":"sqldbs","z":"ec714e97.d73b58","mydb":"8df7f8b0.bd44c","querytype":"select","name":"","x":723.5714111328125,"y":1644.6428833007812,"wires":[["de837ef9.5c1cf8"]]},{"id":"7c116e0a.f8d67","type":"function","z":"ec714e97.d73b58","name":"","func":"msq.topic = \"Select * from User\"\nreturn msg;","outputs":1,"noerr":0,"x":469.28570556640625,"y":1613.9286499023438,"wires":[["98e22918.79bc4"]]},{"id":"de837ef9.5c1cf8","type":"http response","z":"ec714e97.d73b58","name":"","statusCode":"","headers":{},"x":922.1428833007812,"y":1677.8570861816406,"wires":[]},{"id":"8df7f8b0.bd44c","type":"sqldbsdatabase","z":"","host":"127.0.0.1","port":"1433","db":"test","dialect":"mysql"}]

Solution

  • You need to make sure that it's the same message object that flows from the http-in node all the way to the http-out node.

    This message object will have fields of msg.req and msg.res and the msg.res field will be used by the http-out node to send the response back to the browser.

    Any node that takes an input and then forwards it on should preserve these field and not just create a new object for the output. All the built in nodes do this correctly and as should all the published 3rd party nodes. If you find one that does not follow this pattern you should raise a bug with the maintainer.

    Your flow looks ok, but I've never used the DB nodes you have so can't comment on those.