Class: GraphQL::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/graphql/client.rb,
lib/graphql/client/http.rb,
lib/graphql/client/error.rb,
lib/graphql/client/erubis.rb,
lib/graphql/client/railtie.rb,
lib/graphql/client/response.rb,
lib/graphql/client/view_module.rb,
lib/graphql/client/query_result.rb,
lib/graphql/client/log_subscriber.rb

Overview

GraphQL Client helps build and execute queries against a GraphQL backend.

A client instance SHOULD be configured with a schema to enable query validation. And SHOULD also be configured with a backend “execute” adapter to point at a remote GraphQL HTTP service or execute directly against a Schema object.

Defined Under Namespace

Modules: LazyName, ViewModule Classes: Definition, Error, Erubis, FailedResponse, FragmentDefinition, HTTP, LogSubscriber, OperationDefinition, PartialResponse, QueryResult, Railtie, Response, ResponseError, ResponseErrors, SuccessfulResponse, ValidationError

Constant Summary collapse

IntrospectionDocument = 
GraphQL.parse(GraphQL::Introspection::INTROSPECTION_QUERY).deep_freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(schema: nil, execute: nil) ⇒ Client

Returns a new instance of Client.



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# File 'lib/graphql/client.rb', line 39

def initialize(schema: nil, execute: nil)
  @schema = self.class.load_schema(schema)
  @execute = execute
  @document = GraphQL::Language::Nodes::Document.new(definitions: [])
  @document_tracking_enabled = false
end

Instance Attribute Details

#document ⇒ Object (readonly)

Returns the value of attribute document.



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# File 'lib/graphql/client.rb', line 207

def document
  @document
end

#document_tracking_enabled ⇒ Object

Returns the value of attribute document_tracking_enabled.



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# File 'lib/graphql/client.rb', line 22

def document_tracking_enabled
  @document_tracking_enabled
end

#execute ⇒ Object (readonly)

Returns the value of attribute execute.



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# File 'lib/graphql/client.rb', line 20

def execute
  @execute
end

#schema ⇒ Object (readonly)

Returns the value of attribute schema.



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# File 'lib/graphql/client.rb', line 20

def schema
  @schema
end

Class Method Details

.load_schema(schema) ⇒ Object 



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# File 'lib/graphql/client.rb', line 24

def self.load_schema(schema)
  case schema
  when GraphQL::Schema
    schema
  when Hash
    GraphQL::Schema::Loader.load(schema)
  when String
    if schema.end_with?(".json")
      load_schema(File.read(schema))
    else
      load_schema(JSON.parse(schema))
    end
  end
end

Instance Method Details

#fetch_schema ⇒ Object 



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# File 'lib/graphql/client.rb', line 241

def fetch_schema
  execute.execute(
    document: IntrospectionDocument,
    operation_name: "IntrospectionQuery",
    variables: {},
    context: {}
  )
end

#parse(str, filename = nil, lineno = nil) ⇒ Object 



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# File 'lib/graphql/client.rb', line 119

def parse(str, filename = nil, lineno = nil)
  if filename.nil? || lineno.nil?
    filename, lineno, = caller(1, 1).first.split(":", 3)
    lineno = lineno.to_i
  end

  definition_dependencies = Set.new

  str = str.gsub(/\.\.\.([a-zA-Z0-9_]+(::[a-zA-Z0-9_]+)+)/) do
    match = Regexp.last_match
    const_name = match[1]
    case fragment = ActiveSupport::Inflector.safe_constantize(const_name)
    when FragmentDefinition
      definition_dependencies.merge(fragment.document.definitions)
      "...#{fragment.definition_name}"
    else
      message = if fragment
                  "expected #{const_name} to be a #{FragmentDefinition}, but was a #{fragment.class}"
                else
                  "uninitialized constant #{const_name}"
                end

      error = ValidationError.new(message)
      if filename && lineno
        error.set_backtrace(["#{filename}:#{lineno + match.pre_match.count("\n") + 1}"] + caller)
      end
      raise error
    end
  end

  doc = GraphQL.parse(str)

  doc.definitions.each do |node|
    node.name ||= "__anonymous__"
  end

  document_dependencies = Language::Nodes::Document.new(definitions: doc.definitions + definition_dependencies.to_a)

  if @schema
    rules = GraphQL::StaticValidation::ALL_RULES - [GraphQL::StaticValidation::FragmentsAreUsed]
    validator = GraphQL::StaticValidation::Validator.new(schema: @schema, rules: rules)
    query = GraphQL::Query.new(@schema, document: document_dependencies)

    errors = validator.validate(query)
    errors.fetch(:errors).each do |error|
      validation_line = error["locations"][0]["line"]
      error = ValidationError.new(error["message"])
      error.set_backtrace(["#{filename}:#{lineno + validation_line}"] + caller) if filename && lineno
      raise error
    end
  end

  definitions = {}
  doc.definitions.each do |node|
    node.name = nil if node.name == "__anonymous__"
    sliced_document = Language::OperationSlice.slice(document_dependencies, node.name)
    definition = Definition.for(node: node, document: sliced_document)
    definitions[node.name] = definition
  end

  rename_node = ->(node, _parent) do
    definition = definitions[node.name]
    if definition
      node.extend(LazyName)
      node.name = -> { definition.definition_name }
    end
  end
  visitor = Language::Visitor.new(doc)
  visitor[Language::Nodes::FragmentDefinition].leave << rename_node
  visitor[Language::Nodes::OperationDefinition].leave << rename_node
  visitor[Language::Nodes::FragmentSpread].leave << rename_node
  visitor.visit

  doc.deep_freeze

  document.definitions.concat(doc.definitions) if document_tracking_enabled

  if definitions[nil]
    definitions[nil]
  else
    Module.new do
      definitions.each do |name, definition|
        const_set(name, definition)
      end
    end
  end
end

#query(definition, variables: {}, context: {}) ⇒ Object

Raises:



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# File 'lib/graphql/client.rb', line 209

def query(definition, variables: {}, context: {})
  raise Error, "client network execution not configured" unless execute

  unless definition.is_a?(OperationDefinition)
    raise TypeError, "expected definition to be a #{OperationDefinition.name} but was #{document.class.name}"
  end

  document = definition.document
  operation = definition.definition_node

  payload = {
    document: document,
    operation_name: operation.name,
    operation_type: operation.operation_type,
    variables: variables,
    context: context
  }

  result = ActiveSupport::Notifications.instrument("query.graphql", payload) do
    execute.execute(
      document: document,
      operation_name: operation.name,
      variables: variables,
      context: context
    )
  end

  Response.for(definition, result)
end