Module: GraphQL::Schema::Loader

Extended by:
Loader
Included in:
Loader
Defined in:
lib/graphql/schema/loader.rb

Overview

You can use the result of Introspection::INTROSPECTION_QUERY to make a schema. This schema is missing some important details like resolve functions, but it does include the full type system, so you can use it to validate queries.

See Also:

Constant Summary collapse

NullScalarCoerce = 
->(val, _ctx) { val }

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.build_arguments(arg_owner, args, type_resolver) ⇒ Object 



195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
 
# File 'lib/graphql/schema/loader.rb', line 195

def build_arguments(arg_owner, args, type_resolver)
  args.each do |arg|
    kwargs = {
      type: type_resolver.call(arg["type"]),
      description: arg["description"],
      deprecation_reason: arg["deprecationReason"],
      required: false,
      method_access: false,
      camelize: false,
    }

    if arg["defaultValue"]
      default_value_str = arg["defaultValue"]

      dummy_query_str = "query getStuff($var: InputObj = #{default_value_str}) { __typename }"

      # Returns a `GraphQL::Language::Nodes::Document`:
      dummy_query_ast = GraphQL.parse(dummy_query_str)

      # Reach into the AST for the default value:
      input_value_ast = dummy_query_ast.definitions.first.variables.first.default_value

      kwargs[:default_value] = extract_default_value(default_value_str, input_value_ast)
    end

    arg_owner.argument(arg["name"], **kwargs)
  end
end

.build_fields(type_defn, fields, type_resolver) ⇒ Object 



169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
 
# File 'lib/graphql/schema/loader.rb', line 169

def build_fields(type_defn, fields, type_resolver)
  loader = self
  fields.each do |field_hash|
    unwrapped_field_hash = field_hash
    while (of_type = unwrapped_field_hash["ofType"])
      unwrapped_field_hash = of_type
    end
    type_name = unwrapped_field_hash["name"]

    type_defn.field(
      field_hash["name"],
      type: type_resolver.call(field_hash["type"]),
      description: field_hash["description"],
      deprecation_reason: field_hash["deprecationReason"],
      null: true,
      camelize: false,
      connection_extension: nil,
      connection: type_name.end_with?("Connection"),
    ) do
      if field_hash["args"].any?
        loader.build_arguments(self, field_hash["args"], type_resolver)
      end
    end
  end
end

Instance Method Details

#load(introspection_result) ⇒ Class

Create schema with the result of an introspection query.

Parameters:

Returns:

  • (Class) —

    the schema described by input



16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
 
# File 'lib/graphql/schema/loader.rb', line 16

def load(introspection_result)
  schema = introspection_result.fetch("data").fetch("__schema")

  types = {}
  type_resolver = ->(type) { resolve_type(types, type) }

  schema.fetch("types").each do |type|
    next if type.fetch("name").start_with?("__")
    type_object = define_type(type, type_resolver)
    types[type["name"]] = type_object
  end

  directives = []
  schema.fetch("directives", []).each do |directive|
    next if GraphQL::Schema.default_directives.include?(directive.fetch("name"))
    directives << define_directive(directive, type_resolver)
  end

  Class.new(GraphQL::Schema) do
    orphan_types(types.values)
    directives(directives)

    def self.resolve_type(*)
      raise(GraphQL::RequiredImplementationMissingError, "This schema was loaded from string, so it can't resolve types for objects")
    end

    [:query, :mutation, :subscription].each do |root|
      type = schema["#{root}Type"]
      if type
        type_defn = types.fetch(type.fetch("name"))
        self.public_send(root, type_defn)
      end
    end
  end
end