GraphQL::ResultCache (v0.1.x)

This gem is to cache the json result, instead of resolved object.

Installation

Add this line to your application's Gemfile:

gem 'graphql-result_cache', '~> 0.1.8'

And then execute:

$ bundle

Or install it yourself as:

$ gem install graphql-result_cache

Usage

1. Use GraphQL::ResultCache as a plugin in your schema.

class MySchema < GraphQL::Schema
  mutation Types::MutationType
  query Types::QueryType
 
  use GraphQL::ResultCache
end

2. Add the custom field class to accept result_cache metadata.

module Types
  class BaseObject < GraphQL::Schema::Object
    field_class GraphQL::ResultCache::Field
  end
end

3. Config the fields which need to be cached with result_cache definition.

field :theme, Types::ThemeType, null: false, result_cache: true

4. Wrap query result with GraphQL::ResultCache::Result.

class GraphqlController < ApplicationController
  def execute
    # ...
    result = if params[:_json]
               multiple_execute(params[:_json], context: context)
             else
               execute_query(context: context)
             end
    render json: GraphQL::ResultCache::Result.new(result)
  end
end

Result Cache Customization

Cache condition

field :theme, Types::ThemeType, null: false, result_cache: { if: :published? }

The if condition can be either a Symbol or a Proc.

Customized cache key

By default, GraphQL::ResultCache will generate a cache key combining the field path, arguments and object. But you can customize the object clause by specify the key option.

field :theme, Types::ThemeType, null: false, result_cache: { key: :theme_cache_key }

The key can be either a Symbol or a Proc.

Callback after cached result applied

An after_process callback can be provided, eg. when some dynamic values need to be amended after cached result applied.

field :theme, Types::ThemeType, null: false, result_cache: { after_process: :amend_dynamic_attributes }

def amend_dynamic_attributes(theme_node)
  theme_node.merge! used_count: object.theme.used_count
end

Global Configuration

GraphQL::ResultCache can be configured in initializer.

# config/initializers/graphql/result_cache.rb

GraphQL::ResultCache.configure do |config|
  config.namespace   = "GraphQL:Result"                         # Cache key namespace
  config.expires_in  = 1.hour                                   # Expire time for the cache, default to 1.hour
  config.client_hash = -> { Rails.cache.read(:deploy_version) } # GraphQL client package hash key, used in cache key generation, default to nil
  config.except = ->(ctx) { !ctx[:result_cacheable] }           # Exception rule, skip the cache while evaluated as true, default to nil
  config.cache       = Rails.cache                              # The cache object, default to Rails.cache in Rails
  config.logger      = Rails.logger                             # The Logger, default to Rails.logger in Rails
end

When using with introspection, you need to assign custom introspection to avoid getting the nullable type for a non-null type.

class MySchema < GraphQL::Schema
  introspection ::GraphQL::ResultCache::Introspection
end