Dunamic key and expires in

README.md

@@ -32,14 +32,20 @@ module MyApi < Grape::API
     desc "Return a post"
     get ":id" do
       post = Post.find(params[:id])
-      cache(key: "api:posts:#{post.id}", etag: post.updated_at, expires_in: 2.hours) do
+      cache(key: "api:posts:#{post.id}", etag: post.updated_at, expires_in: 2.hours, if: -> { !params[:onair] }) do
         post # post.extend(PostRepresenter) etc, any code that renders response
       end
     end
   end
 end
 ```
 
+You can use blocks and symbols as values for `cache` params they will be evaluated in context of `Grape::Endpoint` (see [Uber gem](https://github.com/apotonick/uber#dynamic-options))
+
+```ruby
+cache(key: -> { "#{request.path}?#{declared_params.except(:client_d).to_json}" }
+```
+
 ## Contributing
 
 1. Fork it

grape-rails-cache.gemspec

@@ -20,6 +20,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "grape"
   spec.add_dependency "activesupport"
+  spec.add_dependency "uber", "~> 0.0.15"
 
   spec.add_development_dependency "bundler", "~> 1.3"
   spec.add_development_dependency "rake"

lib/grape/rails/cache.rb

@@ -42,6 +42,8 @@ def default_expire_time
           end
 
           def cache(opts = {}, &block)
+            opts = Uber::Options.new(opts.reverse_merge(if: true)).evaluate(self)
+
             # HTTP Cache
             cache_key = opts[:key]
 
@@ -55,7 +57,12 @@ def cache(opts = {}, &block)
 
             # Try to fetch from server side cache
             cache_store_expire_time = opts[:cache_store_expires_in] || opts[:expires_in] || default_expire_time
-            ::Rails.cache.fetch(cache_key, raw: true, expires_in: cache_store_expire_time) do
+
+            if opts[:if] && cache_store_expire_time > 0
+              ::Rails.cache.fetch(cache_key, raw: true, expires_in: cache_store_expire_time) do
+                block.call.to_json
+              end
+            else
               block.call.to_json
             end
           end