A GraphQL parser and resolver for Elixir.
This project is still a work in progress, but the eventual goal is to support the full GraphQL spec.
Build a basic AST from a doc
"{ user { id, firstName, lastName }}"|>Plot.parse# returns:{:ok,[{:query,nil,[{:object,"user",nil,[],[{:field,"id",nil,[]},{:field,"firstName",nil,[]},{:field,"lastName",nil,[]}]}]}]}Build Plot objects from a doc
"{ user { id, firstName, lastName }}"|>Plot.parse_and_generate# returns:%Plot.Document{fragments:[],operations:[%Plot.Query{name:nil,objects:[%Plot.Object{alias:nil,args:[],name:"user",fields:[%Plot.Field{alias:nil,args:[],name:"lastName"},%Plot.Field{alias:nil,args:[],name:"firstName"},%Plot.Field{alias:nil,args:[],name:"id"}]}]}],variables:[]}Query resolution works via Elixir protocols. Implement theResolution protocol for the various nodes of your queries.
# ImplementationdefimplPlot.Resolution,for:Plot.Objectdodefresolve(%Plot.Object{name:"user"}=_obj,_context)do%{"firstName"=>"Phil","lastName"=>"Burrows",dontInclude:"this"}enddefresolve(%Plot.Object{name:"birthday"},_context)do%{"day"=>15,"month"=>12,"year"=>2015}endend# Resolutiondoc="{user {firstName, lastName, birthday {month, year}}}"|>Plot.parse_and_generatedoc.operations|>Enum.at(0)|>Plot.Resolver.resolve# returns:[%{"user"=>%{"birthday"=>%{"month"=>12,"year"=>2015},"firstName"=>"Phil","lastName"=>"Burrows"}}]