Module: Harbor::ViewContext::Helpers::Cache

Included in:
Harbor::ViewContext
Defined in:
lib/harbor/view_context/helpers/cache.rb

Overview

Cache helper that provides fragment-caching

Defined Under Namespace

Classes: CacheRenderError

Instance Method Summary collapse

Instance Method Details

#cache(key, ttl = 30 * 60, max_age = nil, &generator) ⇒ Object

Caches the result of a block using the given TTL and maximum_age values.

If no ttl is given, a default of 30 minutes is used.  If no maximum_age value is given
the item will expire after Time.now + ttl.  If a maximum_age is specified, "get" requests
to the cache for a given key will push the expiration time up for the item by the TTL, until
Time.now + TTL is equal to or greater than the cache-insertion-time + maximum_age.



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# File 'lib/harbor/view_context/helpers/cache.rb', line 52

def cache(key, ttl = 30 * 60, max_age = nil, &generator)
  store = @cache_store || Harbor::View.cache

  if store.nil?
    raise ArgumentError.new("Cache Store Not Defined.  Please set Harbor::View.cache to your desired cache store.")
  end

  content = if item = store.get(key)
    begin
      item.content
    rescue => e
      raise CacheRenderError.new(e, item)
    end
  else
    data = capture(&generator)
    store.put(key, data, ttl, max_age)

    data
  end

  with_buffer(generator) do |buffer|
    buffer << content
  end
end