A spinneret breadcrumbs example.

breadcrumbs.lisp

(defvar *breadcrumbs*)


(defun render-breadcrumbs ()
  (with-html
      (:ul
       (loop for (text . url) in *breadcrums*
          do (:li (:a :href url
                      text))))))

(defun add-breadcrumb (text url)
  (push (cons text url)
        *breadcrumbs*))


(defun render-block-foo ()
  (with-html
      (:div :class "foo"
            "Hello")
    (add-breadcrumb "foo" "/foo")
    (render-block-bar)))

(defun render-block-bar ()
  (with-html
      (:div :class "foo"
            "Hello")
    (add-breadcrumb "bar" "/foo/bar")))

(defun render-page ()
  (let* ((*breadcrumbs* nil)
         (main-content (with-html-string
                           (render-block-foo)))
         (breadcrumbs (with-html-string
                          (render-breadcrumbs))))
    (with-html
        (:body (:header
                (:raw breadcrumbs))
               (:section
                (:raw main-content))))))