Some examples of CL-EMB usage

  1. Combining CL-EMB with CL-WHO
  2. A simple loop
  3. Build a dropdown
  4. Mark invalid form fields
  5. Using generic templates
Combining CL-EMB with CL-WHO
Description You can mix several methods of HTML generating together. Think of Lisp Markup Languages like CL-WHO. (Example code from the CL-WHO documentation.)
Dependencies CL-WHO
<h1>Music links</h1>
(cl-who:with-html-output (*standard-output*)
  (loop for (link . title) in 
        '(("" . "Frank Zappa")
          ("" . "Marcus Miller")
          ("" . "Miles Davis"))
        do (cl-who:htm (:a :href link
                           (:b (cl-who:str title)))
A simple loop
Description The "Music links" example with template tags and a loop. This example isn't meant to prove anything! Use the method which fits your problem!
The output of the title gets escaped by CL-EMB ("-escape html"). Depending on the situation you'd rather escape the output yourself and don't want to use any complicated modifiers in the template code itself.
  ((:link "" :title "Frank Zappa")
   (:link "" :title "Marcus Miller")
   (:link "" :title "Miles Davis")))
Dependencies -
<h1>Music links</h1>
<% @loop music-list %>
<a href="<% @var link %>"><b><% @var title -escape html%></b></a><br />
<% @endloop %>
Build a dropdown
Description You can mix template style with embedded Common Lisp style. This example shows how to access the plist ENV. Within the loop (@loop) ENV gets bound to every plist in the list.
TBNL is used to access a submitted parameter "product" and compare it to the current value attribute of the option element.
Remember the escaping! Set cl-emb:*escape-type* to :html and all output of @var will be escaped correctly.
  ((:value "foo1" :text "Super Foo")
   (:value "fooxl" :text "Super Foo XL")
   (:value "bar2000" :text "Ultra Bar 2000")
   (:value "hl2" :text "Half-Life 2")
   (:value "dn4e4" :text "Vaporware")))
Dependencies TBNL
<select name="product">
  <% @loop products %>
    <option value="<% @var value %>"<%
      (when (equal (getf env :value) (tbnl:parameter "product")) 
    %> selected="selected"<% ) %>><% @var text %></option>
  <% @endloop %>
Mark invalid form fields
Description Validate a form and mark the errors in the ENV plist.
Again: Remember the escaping!
'(:email "stesch@home" :email-error t)
Dependencies -
<% @if email-error %>
  <span class="error">Please provide valid e-mail address</span><br />
<% @endif %>
<input type="text" name="email" value="<% @var email %>"/>
Using generic templates
Description You want to use generic templates which can be called with a defined set of parameters? Then @with and @endwith is what you are looking for. It sets the current ENV to the one accessed by a given name. See the example below, which calls a template for textinput fields.
'(:name (:name "name"
         :length 40)
  :e-mail (:name "email"
           :value "no@no"
           :error t
           :length 120))
Dependencies -
Please enter your name:<br />
<% @with name %>
  <% @include "includes/textinput.tmpl" %>
<% @endwith %>
<br />
Please enter your e-mail address:<br />
<small>(Use the TLD <em>.invalid</em>
if you don't want to receive mail</small>
<% @with e-mail %>
  <% @include "includes/textinput.tmpl" %>
<% @endwith %>