Apq
Support for Automatic Persisted Queries in Absinthe. Query documents in GraphQL can be be of a significant size. Especially on mobile it may be beneficial to limit the size of the queries so fewer bytes go across the network. APQ uses a deterministic hash of the input query in a request. If the server does not know the hash the client can retry the request with the expanded query. The server can use this request to store the query in its cache.
You’ll need a GraphQL client that can use APQ, such as Apollo Client.
Complete example project is available here
Installation
If available in Hex, the package can be installed
by adding apq
to your list of dependencies in mix.exs
:
def deps do
[
{:apq, "~> 1.0.0"}
]
end
Examples
Define a new module and use Apq.DocumentProvider
:
defmodule ApqExample.Apq do
use Apq.DocumentProvider,
cache_provider: ApqExample.Cache,
max_query_size: 16384 #default
end
You’ll need to implement a cache provider. This is up to you, in this example I use Cachex but you could use a Genserver, Redis or anything else.
Define a module for the cache, e.g when using Cachex:
defmodule ApqExample.Cache do
@behaviour Apq.CacheProvider
def get(hash) do
Cachex.get(:apq_cache, hash)
end
def put(hash, query) do
Cachex.put(:apq_cache, hash, query)
end
end
When using Cachex you’ll need to start it in your supervision tree:
worker(Cachex, [ :apq_cache, [ limit: 100 ] ])
Now we need to add the ApqExample.Apq
module to the list of document providers. This goes in your router file.
match("/api",
to: Absinthe.Plug,
init_opts: [
schema: ApqExample.Schema,
json_codec: Jason,
interface: :playground,
document_providers: [ApqExample.Apq, Absinthe.Plug.DocumentProvider.Default]
]
)
This is it, if you query with a client that has support for Apq it should work with Absinthe.
Documentation
Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/apq.