Tutorial 2 - Clojure Web Application Using Noir
Posted by: Deepali | 01 Mar 2013 | CommentsIn this tutorial we are going to cover how to apply form validations in Noir.
Open src/finance_manager/views/welcome.clj file write following code
in it.
(:require [noir.validation :as vali])
(defn valid-budget? [{:keys [budget_date budget_amt]}]
(vali/rule (vali/has-value? budget_date)
[:budget_date "Budget Date Is Required."])
(vali/rule (vali/has-value? budget_amt)
[:budget_amt "Budget Amount Is Required."])
(not (vali/errors? :budget_date :budget_amt)))
The above function will check that all the fields confirm to the rules, such as budget_date and budget_amt are provided.
The rule have following form:
(rule passed? [field error])
If the passed? condition is not met, add the error text to the given field.
We will need a helper for displaying the error on the page:
(defpartial error-item [[first-error]]
[:p.error first-error]
)
Modify the /addbudget page as:
(defpage "/addbudget" {:keys [error]}
(common/layout
[:h2 "Add Monthly Budget"]
[:div.error error]
(form-to [:post "/addbudget"]
(vali/on-error :budget_date error-item)
(label "budget_date" "Select Budget Date")
(text-field "budget_date")
[:br]
(vali/on-error :budget_amt error-item)
(label "budget_amt" "Budget Amount")
(text-field "budget_amt")
[:br]
(submit-button "Add Budget")
(reset-button "Cancel")
)
)
)
Modify the [:post "/addbudget"] page as:
(defpage [:post "/addbudget"] budget
(if (valid-budget? budget)
(let
(try
(db/add-budget budget)
(resp/redirect "/homepage")
(catch Exception ex
(render "/addbudget" (assoc budget :error (.getMessage ex)))
)
)
)
(render "/addbudget")
)
)
If the budget is valid then it will add the record in the database. And
if the budget is not valid then it will render to "/addbudget" page
and displays respected errors on that page.