Rails rendering extension for more server-side html caching

Why do I need this?

To improve fragment caching efficiency in Rails by only caching the things that change. Use this gem after you have configured as much in-memory caching as possible using standard techniques such as Russian Doll caching.

Install

Add this line to your Gemfile:

gem 'cache_replace'

Add this line to a helper file, likely your ApplicationHelper:

include CacheReplace

Use

This gem allows you to easily cache a partial of static html and replace inner dynamic html. Here is an example scenario:

You have some html that would be cached, except for some uncacheable code nested in the DOM. For example:

file.html.haml:

= render 'container'

_container.html.haml:

.lots
  .of
    .htmls
      = render 'dynamic'

_dynamic.html.haml:

= complicated_uncacheable_stuff

In the scenario above, you can't cache anything without resorting to madness. With cache_replace, you can:

file.html.haml:

= render_cached 'container', replace: 'dynamic'

_container.html.haml:

- cache "container" do
  .lots
    .of
      .htmls
        = cache_replace_key 'dynamic'

_dynamic.html.haml:

= complicated_uncacheable_stuff

In the above example, you could also remove the _dynamic.html.haml file like so:

file.html.haml:

= render_cached 'container', replace: {dynamic: complicated_uncacheable_stuff}

Options

render_cached provides 4 calling styles:

Single partial to replace

render_cached "container", replace: "inner"

Array of partials to replace

render_cached "container", replace: ["inner"]

Map of keys to replace with values

render_cached "container", replace: {key_name: a_helper_method(object)}

Yield to a hash of keys to replace with values

render_cached "container" do
  {key_name: a_helper_method(object)}
end

Contribute

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request