Common things you may want to do with flower:

Change the site title

Add (def site-title "my-title") to expressions/constants.clj.

Pass an optional argument to a template

In the template, use (expressions.meta/locals) to get a key-value map of all variables passed as arguments. For example, ◊(if-let [head ('head (locals))] head) will put head into the template only if it exists. In this particular case, you could write this more concisely as ◊('head (locals)).

Use a custom order for your pages

In index.html (or wherever you put your index page), pass a custom sorter into categorize:

<ul class="post-list">◊(for [post (:main-posts (categorize pages custom-sort))])«
 <!-- ... -->
»</ul>

Here is a sample custom comparator which uses a hard-coded order:

◊(require '[expressions.pages :refer [categorize sort-by-constant-name]])
◊(def page-order ["quickstart" "syntax" "language"])
◊(categorize pages #(sort-by-constant-name % page-order))

Rewrite an HTML page

Flower currently exposes a stateful API for HTML transformations, which means you need an object reference to hold on to. Once you have an object reference, you can modify it with CSS selectors.

(ns transformers.add-class
  (:require [expressions.html :refer [->element select add-class!]]))
(defn transform [{:keys [:content]}]
  (let [doc (->element page)]
    (doseq [anchor (select doc "a")]
      (add-class! anchor "my-anchor-class"))
    (str doc)))

Make sure to call str at the end. Otherwise, you'll pass through a parsed HTML document, which will likely crash the next transformer that runs if it expects a string.

Override only a single function from a clojure defaults file

First, create a file with the same name (e.g. expressions/pages.clj). Then, redefine all the vars from the default namespace into the current namespace:

(ns expressions.pages
  (:require defaults.expressions.pages))
(doseq [[sym var] (ns-publics 'defaults.expressions.pages)]
  (intern 'expressions.pages sym var))