GNU ELPA - graphql

GraphQL.el

GraphQL.el provides a set of generic functions for interacting with GraphQL web services.

See also the following resources:

• GraphQL language service and lsp-mode
• graphql-mode
• This brief overview of GraphQL syntax

Syntax Overview

Two macros are provided to express GraphQL queries and mutations:

• graphql-query encodes the graph provided under a root (query ...) node.
• graphql-mutation encodes the graph provided under a root (mutation ...) node.

Both macros allow special syntax for query/mutation parameters if this is desired; see the docstrings for details. I will note that backtick notation usually feels more natural in Lisp code.

Basic Queries

The body of these macros is the graph of your query/mutation expressed in a Lispy DSL. Generally speaking, we represent fields as symbols and edges as nested lists with the edge name being the head of that list. For example,

emacs-lisp (graphql-query (myField1 myField2 (myEdges (edges (node myField3)))))

will construct a query that retrieves myField1, myField2, and myField3 for every node in myEdges. The query is returned as a string without any unnecessary whitespace (i.e., formatting) added.

Following Edges

Multiple edges can of course be followed. Here's an example using GitHub's API:

emacs-lisp (graphql-query ((viewer login) (rateLimit limit cost remaining resetAt)))

Passing Arguments

Usually, queries need explicit arguments. We pass them in an alist set off by the :arguments keyword:

emacs-lisp (graphql-query ((repository :arguments ((owner . "github") (name . ($ repo))) (issues :arguments ((first . 20) (states . [OPEN CLOSED])) (edges (node number title url id))))))

As you can see, strings, numbers, vectors, symbols, and variables can all be given as arguments. The above evaluates to the following (formatting added):

graphql query { repository (owner: "github", name: $repo) { issues (first: 20, states: [OPEN, CLOSED]) { edges { node { number title url id } } } } }

Objects as arguments work, too, though practical examples seem harder to come by:

emacs-lisp (graphql-query ((object :arguments ((someVariable . ((someComplex . "object") (with . ($ complexNeeds))))))))

gives

graphql query { object ( someVariable: { someComplex: "object", with: $complexNeeds } ) }

Working with Responses

• graphql-simplify-response-edges

  Simplify structures like

  (field (edges ((node node1values...)) ((node node2values...))))

  into (field (node1values) (node2values)).

Keyword Reference

• :arguments

  Pass arguments to fields as an alist of parameters (as symbols) to values. See graphql--encode-argument-value.

• :op-name, :op-params

  Operation name/parameters. Given to top-level query or mutation operations for later re-use. You should rarely (if ever) need to supply these yourself; the graphql-query and graphql-mutation macros give you natural syntax to do this.

Planned

• :as keyword for aliases (graphql-encode).

• ... qualifier for fragments and inline fragments (graphql--encode-object)