instance method `etag=`

Ruby on Rails 7.0.10

Since v3.0.20

Available in: v3.0.20 v3.1.12 v3.2.22.5 v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

etag=(weak_validators)

This method sets a weak ETag validator on the response so browsers and proxies may cache the response, keyed on the ETag. On subsequent requests, the If-None-Match header is set to the cached ETag. If it matches the current ETag, we can return a 304 Not Modified response with no body, letting the browser or proxy know that their cache is current. Big savings in request time and network bandwidth.

Weak ETags are considered to be semantically equivalent but not byte-for-byte identical. This is perfect for browser caching of HTML pages where we don’t care about exact equality, just what the user is viewing.

Strong ETags are considered byte-for-byte identical. They allow a browser or proxy cache to support Range requests, useful for paging through a PDF file or scrubbing through a video. Some CDNs only support strong ETags and will ignore weak ETags entirely.

Weak ETags are what we almost always need, so they’re the default. Check out #strong_etag= to provide a strong ETag validator.

Parameters

weak_validators req

Source

# File actionpack/lib/action_dispatch/http/cache.rb, line 101
        def etag=(weak_validators)
          self.weak_etag = weak_validators
        end

Defined in actionpack/lib/action_dispatch/http/cache.rb line 101 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActionDispatch::Http::Cache::Response

Signature

Parameters