codonovan / foam

Foam

A hack to add server-side rendering to Om

Assumes you have a working CLJS Om app, and you want to add server-side rendering, without using selenium or node.

Usage

foam provides a minimal reimplementation of the om.core, om.dom namespaces in .clj code. Port your Om components and app-state to .cljc code. In your component namespaces:

(:require #?(:clj [foam.core :as om]
             :cljs [om.core :as om])
          #?(:clj [foam.dom :as dom]
             :cljs [om.dom :as dom]))

Everything should work without needing to modify your component code, with the exception of a few known limitations listed below.

Server-side Rendering

In clj, call

(ns foo.bar
  (:require [foam.core :as foam]
            [foam.dom :as dom]))

(let [state (your-app-state)
      cursor (foam/root-cursor state)
      com (foam/build your-component cursor)]
 (dom/render-to-string com)

Serve that in your http response.

Limitations

Lots. This is alpha, though Rasterize is using it in produciton. This list of limitations is not complete.

• Not all Om protocols have been ported over yet
• Bugs everywhere
• Most unusual options aren't supported yet. Cursors and app-state can currently only be maps.
• because CLJ doesn't support Javascript's ... special... arity-overloading, your om component functions must use the 3 arg constructor: (defn foo [app owner opts]), rather than the 2-arg constructor: (defn foo [app owner]). foam.core/build only provides the 3 arity version, to reduce confusion.

License

Copyright © 2015 Allen Rohner

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.

Contains code adapted from Om

Contains code adapted from hiccup

Contains code adapted from sablono