async_render.js.coffee.erb

# Example
#
#
#<div class="cached-async-render"
#     data-url="/my_dynamic_template.html"
#     data-cache-key="foo-user"
#     data-cache-expires-in="120"
#     data-success-callback="initializeThings()">
#  loading...       
#</div>
#
#   Usage
#
#   To a container element add css class 'async-render' and attribute data-url with url to be called.
#   this will call url and replace elements content with returned html
#     options are:
#       data-url, data-success-callback
#
#   With class 'cached-async-render" html will be cached locally to avoid constant requests.
#     options are:
#         data-url , data-cache-key, data-cache-expires-in, data-success-callback
#
# Author: Dwayne Macgowan
$(document).ready ->

  cache = new Cache(-1, false, new Cache.LocalStorageCacheStorage())

  $(".cached-async-render").each (i) ->
    e = $(this)
    cache_key = e.data('cache-key') || e.data('url')
    expires_in = e.data('cache-expires-in') || 60 # default cache expiration to 1 min

    cached_html = cache.getItem(cache_key)
    if cached_html == null
      $.ajax e.data('url'),
        success: (html_response) ->
          cache.setItem(cache_key,html_response,{expirantionSliding: expires_in})
          e.html html_response
          if e.data('success-callback')
            eval e.data('success-callback')
    else
      e.html cached_html
      if e.data('success-callback')
        eval e.data('success-callback')

  $(".async-render").each (i) ->
    e = $(this)
    $.ajax e.data('url'),
      success: (html_response) ->
        e.html html_response
        if e.data('success-callback')
          eval e.data('success-callback')