yesod-examples-0.4.0: hamlet/synopsis.lhs

---
title: Synopsis - Hamlet
---
\begin{code}
{-# LANGUAGE QuasiQuotes #-}

import Text.Hamlet
import qualified Data.ByteString.Lazy as L

data Person = Person
    { name :: String
    , age :: String
    , page :: PersonUrls
    , isMarried :: Bool
    , children :: [String]
    }
data PersonUrls = Homepage | PersonPage String

renderUrls :: PersonUrls -> String
renderUrls Homepage = "/"
renderUrls (PersonPage name) = '/' : name

footer :: Hamlet url
footer = [$hamlet|
#footer Thank you, come again
|]

template :: Person -> Hamlet PersonUrls
template person = [$hamlet|
!!!
%html
    %head
        %title Hamlet Demo
    %body
        %h1 Information on $string.name.person$
        %p $string.name.person$ is $string.age.person$ years old.
        %h2
            $if isMarried.person
                Married
            $else
                Not married
        %ul
            $forall children.person child
                %li $string.child$
        %p
            %a!href=@page.person@ See the page.
        ^footer^
|]

main :: IO ()
main = do
    let person = Person
            { name = "Michael"
            , age = "twenty five & a half"
            , page = PersonPage "michael"
            , isMarried = True
            , children = ["Adam", "Ben", "Chris"]
            }
    L.putStrLn $ renderHamlet renderUrls $ template person
\end{code}

Outputs (new lines added for readability):
<code><pre>
    &lt;!DOCTYPE html&gt;
    &lt;html&gt;&lt;head&gt;&lt;title&gt;Hamlet Demo&lt;/title&gt;&lt;/head&gt;&lt;body&gt;
    &lt;h1&gt;Information on Michael&lt;/h1&gt;
    &lt;p&gt;Michael is twenty five &amp; a half years old.&lt;/p&gt;
    &lt;h2&gt;Married&lt;/h2&gt;
    &lt;ul&gt;&lt;li&gt;Adam&lt;/li&gt;&lt;li&gt;Ben&lt;/li&gt;&lt;li&gt;Chris&lt;/li&gt;&lt;/ul&gt;
    &lt;p&gt;&lt;a href="/michael"&gt;See the page.&lt;/a&gt;&lt;/p&gt;
    &lt;div id="footer"&gt;Thank you, come again&lt;/div&gt;
    &lt;/body&gt;&lt;/html&gt;
</pre></code>