Handle query parameters passed to an HTTP endpoint

Problem

You want to access the query parameters passed to an HTTP endpoint, such as:

http://example.com/hello-query?name=Nick

Solution

Use the msg.req.query property of the message sent by the HTTP In node to access the parameters.

Example

[{"id":"b34dd1af.4cb23","type":"template","z":"3045204d.cfbae","name":"page","field":"payload","fieldType":"msg","format":"handlebars","syntax":"mustache","template":"<html>\n    <head></head>\n    <body>\n        <h1>Hello {{req.query.name}}!</h1>\n    </body>\n</html>","x":290,"y":180,"wires":[["b828f6a6.47d708"]]},{"id":"1052941d.efad6c","type":"http in","z":"3045204d.cfbae","name":"","url":"/hello-query","method":"get","swaggerDoc":"","x":120,"y":180,"wires":[["b34dd1af.4cb23"]]},{"id":"b828f6a6.47d708","type":"http response","z":"3045204d.cfbae","name":"","x":430,"y":180,"wires":[]}]
[~]$ curl http://localhost:1880/hello-query?name=Nick
<html>
    <head></head>
    <body>
        <h1>Hello Nick!</h1>
    </body>
</html>

Discussion

The msg.req.query property is an object of key/value pairs for each query parameter.

In the above example, a request to /hello-query?name=Nick&colour=blue results in the property containing:

{
    "name": "Nick",
    "colour": "blue"
}

If there are multiple query parameters with the same name, they will be provided as an array. For example, /hello-query?colour=blue&colour=red:

{
    "colour": ["blue","red"]
}