How do I access individual fields of a form in Clojure? - clojure

Question

I'm building my very first web app, and I am having a hard time accessing individual fields of a form when the user submits the form. Here's what I have:
(defroutes app
(GET "/" [] homepage)
(POST "/city" request display-city)
(route/resources "/")
(route/not-found "Not Found"))
(defn display-city [request]
(html5
[:div {:class "the-city"}
[:h2 "ALL ABOUT YOUR CITY"]
[:ul
[:li "Your city is " (str request) "! That's all"]]]))
;; and here's the hiccup form:
[:form {:action "/city" :method "post"}
(anti-forgery-field)
[:p "Enter your home address"]
[:div
[:label {:for "street-field"} "Street:"]
[:input {:id "street-field"
:type "text"
:name "street"}]]
[:div
[:label {:for "city-field"} "City:"]
[:input {:id "city-field"
:type "text"
:name "city"}]
[:div
[:label {:for "state-field"} "State:"]
[:input {:id "state-field"
:type "text"
:name "state"}]
[:label {:for "zip-field"} "ZIP:"]
[:input {:id "zip-field"
:type "text"
:name "zip"
:size "10"}]]
[:div.button
[:button {:type "submit"} "Submit"]]]])
;; When I run the code above, I can see the entire form that's submitted via (str request), in what looks to be a Clojure map. But I can't figure out how to extract individual "key/vals" (from that address form, I'd like to extract the city), or how to store those results in a way that I can use it. Any ideas?
This is a super basic /city page that I am trying to get running to understand how things work before building bigger things. Thanks!

Answer 1

In your request map, there should be a key :form-params with a map of key/value pairs that were POSTed. Here's how you could get an individual value out:
(get-in request [:form-params :city])
Or you could destructure :form-params map to bind many values at once:
(let [{:keys [city state zip]} (:form-params request)]
(format "%s, %s %s" city state zip))