https://github.com/michalmuskala/phoenix_etag
ETag support for phoenix
https://github.com/michalmuskala/phoenix_etag
elixir phoenix
Last synced: 16 days ago
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ETag support for phoenix
- Host: GitHub
- URL: https://github.com/michalmuskala/phoenix_etag
- Owner: michalmuskala
- License: other
- Created: 2017-02-15T00:18:34.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2017-10-11T14:49:46.000Z (over 7 years ago)
- Last Synced: 2025-04-15T01:14:33.158Z (16 days ago)
- Topics: elixir, phoenix
- Language: Elixir
- Size: 22.5 KB
- Stars: 43
- Watchers: 2
- Forks: 5
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# PhoenixETag
Conditional request (ETag & modified-since) support for Phoenix.
Based heavily on code from [hex_web](https://github.com/hexpm/hex_web).
## Usage
The library provides a replacement function for `Phoenix.Controller.render/1-4`
called `PhoenixETag.render_if_stale/1-4` accepting exactly the same arguments.
When called the function expects the view to implement an additional callback:
`stale_checks/2` similar to `render/2` that is responsible for returning the
etag value and/or last modified value for the current resource.
Additional helper `PhoenixETag.schema_etag/1` is provided for generating etag
values of a single or multiple schema structs.
```elixir
# controller
def show(conn, %{"id" => id}) do
data = MyApp.load_data(id)
PhoenixETag.render_if_stale(conn, :show, data: data)
end
# view
def stale_checks("show." <> _format, %{data: data}) do
[etag: PhoenixETag.schema_etag(data),
last_modified: PhoenixETag.schema_last_modified(data)]
end
```
Both the etag and last_modified values are optional. The first one will add an
`etag` header to the response and perform a stale check against the
`if-none-match` header. The second one will add a `last-modified` header to the
response and perform a stale check against the `if-modified-since` header.
If the headers indicate cache is fresh a 304 Not Modified response is triggered,
and rendering of the response is aborted. If headers indicate cache is stale,
render proceeds as normal, except the extra headers are added to the response.
## Installation
If [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `phoenix_etag` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[{:phoenix_etag, "~> 0.1"}]
end
```
Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
be found at [https://hexdocs.pm/phoenix_etag](https://hexdocs.pm/phoenix_etag).