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Diffstat (limited to 'guides/source/caching_with_rails.md')
| -rw-r--r-- | guides/source/caching_with_rails.md | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/guides/source/caching_with_rails.md b/guides/source/caching_with_rails.md index 9a56233e4a..f26019c72e 100644 --- a/guides/source/caching_with_rails.md +++ b/guides/source/caching_with_rails.md @@ -175,11 +175,11 @@ your app will serve stale data. To fix this, we tie the models together with the `touch` method: ```ruby -class Product < ActiveRecord::Base +class Product < ApplicationRecord has_many :games end -class Game < ActiveRecord::Base +class Game < ApplicationRecord belongs_to :product, touch: true end ``` @@ -284,7 +284,7 @@ The most efficient way to implement low-level caching is using the `Rails.cache. Consider the following example. An application has a `Product` model with an instance method that looks up the product’s price on a competing website. The data returned by this method would be perfect for low-level caching: ```ruby -class Product < ActiveRecord::Base +class Product < ApplicationRecord def competing_price Rails.cache.fetch("#{cache_key}/competing_price", expires_in: 12.hours) do Competitor::API.find_price(id) @@ -521,6 +521,14 @@ class ProductsController < ApplicationController end ``` +### A note on weak ETags + +Etags generated by Rails are weak by default. Weak etags allow symantically equivalent responses to have the same etags, even if their bodies do not match exactly. This is useful when we don't want the page to be regenerated for minor changes in response body. If you absolutely need to generate a strong etag, it can be assigned to the header directly. + +```ruby + response.add_header "ETag", Digest::MD5.hexdigest(response.body) +``` + References ---------- |