alumbra.claro

This library offers an alumbra GraphQL executor based on claro.

This executor can be supplied to the alumbra.ring handler function to expose claro resolvables using a GraphQL HTTP endpoint.

Quickstart

Executor Construction

(require '[alumbra.analyzer :as analyzer]
         '[alumbra.parser :as parser]
         '[alumbra.claro :as claro])

An executor is based on a GraphQL schema which can be constructed by using e.g. alumbra's own analyzer and parser:

(def schema
  (analyzer/analyze-schema
    "type Person { id: ID!, name: String!, friends: [Person!] }
     type QueryRoot { person(id: ID!): Person }
     schema { query: QueryRoot }"
    parser/parse-schema))

Now, we define our claro resolvables, ideally one for each non-root type declared in our schema:

(require '[claro.data :as data])

(defrecord Person [id]
  data/Resolvable
  (resolve! [_ {:keys [db]}]
    ...))

The root types have to be given as plain maps of resolvables, e.g. for our QueryRoot:

(def QueryRoot
  {:person (->Person nil)})

A minimal executor can now be constructed using:

(def executor
  (claro/executor
    {:schema schema
     :env    {:db ...}
     :query  QueryRoot}))

Executor Usage

An executor is a function taking a context map, as well as a canonicalized operation, producing a result map with :data and optionally :errors keys.

(->> "{ person(id: \"ID\") { name } }"
     (parser/parse-document)
     (analyzer/canonicalize-operation schema)
     (executor {:session ...}))
;; => {:data ..., :errors ...}

The context map ({:session ...} in this case) will be merged into the claro environment supplied to resolvables. Note that you should validate the GraphQL document between parsing and canonicalization, e.g. using alumbra's validator.

License

MIT License

Copyright (c) 2016 Yannick Scherer

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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