Handling query params (GET variables)

Genie makes it easy to access query params, which are values sent as part of the URL over GET requests (ex: mywebsite.com/index?foo=1&bar=2 foo and bar are query params corresponding to the variables foo = 1 and bar = 2). All these values are automatically collected by Genie and exposed in the params() collection (which is part of the Router module).

Example

using Genie

route("/hi") do
  name = params(:name, "Anon")

  "Hello $name"
end

If you access http://127.0.0.1:8000/hi the app will respond with "Hello Anon" since we're not passing any query params.

However, requesting http://127.0.0.1:8000/hi?name=Adrian will in turn display "Hello Adrian" as we're passing the name query variable with the value Adrian. This variable is exposed by Genie as params(:name).

Genie however provides utility methods for accessing these values in the Requests module.

The Requests module

Genie provides a set of utilities for working with requests data within the Requests module. You can use the getpayload method to retrieve the query params as a Dict{Symbol,Any}. We can rewrite the previous route to take advantage of the Requests utilities.

Example

using Genie, Genie.Requests

route("/hi") do
  "Hello $(getpayload(:name, "Anon"))"
end

The getpayload function has a few specializations, and one of them accepts the key and a default value. The default value is returned if the key variable is not defined. You can see the various implementations for getpayload using the API docs or Julia's help> mode.