absinthe v1.4.12 Absinthe.Schema.Notation View Source

This module contains macros used to build GraphQL types.

See Absinthe.Schema for a rough overview of schema building from scratch.

Link to this section Summary

Functions

Add an argument

Configure a subscription field

Mark a field as deprecated

Defines a description

Defines an enum type

Defines an enum type

Define the expansion for a directive

Defines a GraphQL field

Defines a GraphQL field

Defines a GraphQL field

Import fields from another object

Import types from another module

Calculate the instruction for a directive

Declare an implemented interface for an object

Define an interface type

Declare implemented interfaces for an object

Marks a type reference as a list of the given type

Defines list of metadata’s key/value pair for a custom type

Defines a metadata key/value pair for a custom type

Marks a type reference as non null

Declare a directive as operating an a AST node type

Defines a parse function for a scalar type

Defines a resolve function for a field

Define a type resolver for a union or interface

Defines a scalar type

Define a scalar type

Defines a serialization function for a scalar type

Set a trigger for a subscription field

Defines the types possible under a union type

Defines a value possible under an enum type

Link to this section Functions

Link to this macro arg(identifier, attrs) View Source (macro)

Add an argument.

See arg/3

Link to this macro arg(identifier, type, attrs) View Source (macro)

Add an argument.

Placement

Allowed under: directive field

Examples

field do
  arg :size, :integer
  arg :name, :string, description: "The desired name"
end
Link to this macro complexity(func_ast) View Source (macro)
Link to this macro config(config_fun) View Source (macro)

Configure a subscription field.

Example

config fn args, %{context: context} ->
  if authorized?(context) do
    {:ok, topic: args.client_id}
  else
    {:error, "unauthorized"}
  end
end

See Absinthe.Schema.subscription/1 for details

Link to this macro deprecate(msg) View Source (macro)

Mark a field as deprecated

In most cases you can simply pass the deprecate: “message” attribute. However when using the block form of a field it can be nice to also use this macro.

Placement

Allowed under: field

Examples

field :foo, :string do
  deprecate "Foo will no longer be supported"
end

This is how to deprecate other things

field :foo, :string do
  arg :bar, :integer, deprecate: "This isn't supported either"
end

enum :colors do
  value :red
  value :blue, deprecate: "This isn't supported"
end
Link to this macro description(text) View Source (macro)

Defines a description

This macro adds a description to any other macro which takes a block.

Note that you can also specify a description by using @desc above any item that can take a description attribute.

Placement

Allowed under any block. Not allowed to be top level

Link to this macro directive(identifier, attrs \\ [], list) View Source (macro)

Defines a directive

Placement

Top level in module.

Examples

directive :mydirective do

  arg :if, non_null(:boolean), description: "Skipped when true."

  on Language.FragmentSpread
  on Language.Field
  on Language.InlineFragment

  instruction fn
    %{if: true} ->
      :skip
    _ ->
      :include
  end

end
Link to this macro enum(identifier, attrs) View Source (macro)

Defines an enum type

See enum/3

Link to this macro enum(identifier, attrs, list) View Source (macro)

Defines an enum type

Placement

Top level in module.

Examples

Handling RED, GREEN, BLUE values from the query document:

enum :color do
  value :red
  value :green
  value :blue
end

A given query document might look like:

{
  foo(color: RED)
}

Internally you would get an argument in elixir that looks like:

%{color: :red}

If your return value is an enum, it will get serialized out as:

{"color": "RED"}

You can provide custom value mappings. Here we use r, g, b values:

enum :color do
  value :red, as: "r"
  value :green, as: "g"
  value :blue, as: "b"
end
Link to this macro expand(func_ast) View Source (macro)

Define the expansion for a directive

Placement

Allowed under: directive

Link to this macro field(identifier, attrs) View Source (macro)

Defines a GraphQL field

See field/4

Link to this macro field(identifier, attrs, attrs) View Source (macro)

Defines a GraphQL field

See field/4

Link to this macro field(identifier, type, attrs, list) View Source (macro)

Defines a GraphQL field.

Placement

Allowed under: input_object interface object

query, mutation, and subscription are all objects under the covers, and thus you’ll find field definitions under those as well.

Examples

field :id, :id
field :age, :integer, description: "How old the item is"
field :name, :string do
  description "The name of the item"
end
field :location, type: :location
Link to this macro import_fields(type_name, opts \\ []) View Source (macro)

Import fields from another object

Example

object :news_queries do
  field :all_links, list_of(:link)
  field :main_story, :link
end

object :admin_queries do
  field :users, list_of(:user)
  field :pending_posts, list_of(:post)
end

query do
  import_fields :news_queries
  import_fields :admin_queries
end

Import fields can also be used on objects created inside other modules that you have used import_types on.

defmodule MyApp.Schema.NewsTypes do
  use Absinthe.Schema.Notation

  object :news_queries do
    field :all_links, list_of(:link)
    field :main_story, :link
  end
end
defmodule MyApp.Schema.Schema do
  use Absinthe.Schema

  import_types MyApp.Schema.NewsTypes

  query do
    import_fields :news_queries
    # ...
  end
end
Link to this macro import_types(type_module_ast) View Source (macro)

Import types from another module

Very frequently your schema module will simply have the query and mutation blocks, and you’ll want to break out your other types into other modules. This macro imports those types for use the current module

Placement

Top level in module.

Examples

import_types MyApp.Schema.Types

import_types MyApp.Schema.Types.{TypesA, TypesB, SubTypes.TypesC}
Link to this macro input_object(identifier, attrs \\ [], list) View Source (macro)

Defines an input object

See Absinthe.Type.InputObject

Placement

Top level in module.

Examples

input_object :contact_input do
  field :email, non_null(:string)
end
Link to this macro instruction(func_ast) View Source (macro)

Calculate the instruction for a directive

Placement

Allowed under: directive

Link to this macro interface(identifier) View Source (macro)

Declare an implemented interface for an object.

Adds an Absinthe.Type.Interface to your schema.

See also interfaces/1, which can be used for multiple interfaces, and interface/3, used to define interfaces themselves.

Examples

object :car do
  interface :vehicle
  # ...
end
Link to this macro interface(identifier, attrs \\ [], list) View Source (macro)

Define an interface type.

Adds an Absinthe.Type.Interface to your schema.

Also see interface/1 and interfaces/1, which declare that an object implements one or more interfaces.

Placement

Top level in module.

Examples

interface :vehicle do
  field :wheel_count, :integer
end

object :rally_car do
  field :wheel_count, :integer
  interface :vehicle
end
Link to this macro interfaces(ifaces) View Source (macro)

Declare implemented interfaces for an object.

See also interface/1, which can be used for one interface, and interface/3, used to define interfaces themselves.

Placement

Allowed under: object

Examples

object :car do
  interfaces [:vehicle, :branded]
  # ...
end
Link to this macro is_type_of(func_ast) View Source (macro)

Placement

Allowed under: object

Marks a type reference as a list of the given type

See field/3 for examples

Link to this macro meta(keyword_list) View Source (macro)

Defines list of metadata’s key/value pair for a custom type.

This is generally used to facilitate libraries that want to augment Absinthe functionality

Examples

object :user do
  meta cache: true, ttl: 22_000
end

object :user, meta: [cache: true, ttl: 22_000] do
  # ...
end

The meta can be accessed via the Absinthe.Type.meta/2 function.

user_type = Absinthe.Schema.lookup_type(MyApp.Schema, :user)

Absinthe.Type.meta(user_type, :cache)
#=> true

Absinthe.Type.meta(user_type)
#=> [cache: true, ttl: 22_000]

Placement

Allowed under: enum field input_object interface object scalar union

Link to this macro meta(key, value) View Source (macro)

Defines a metadata key/value pair for a custom type.

For more info see meta/1

Examples

meta :cache, false

Placement

Allowed under: enum field input_object interface object scalar union

Link to this macro middleware(new_middleware, opts \\ []) View Source (macro)
Link to this macro non_null(type) View Source (macro)

Marks a type reference as non null

See field/3 for examples

Link to this macro object(identifier, attrs \\ [], block) View Source (macro)

Define an object type.

Adds an Absinthe.Type.Object to your schema.

Placement

Top level in module.

Examples

Basic definition:

object :car do
  # ...
end

Providing a custom name:

object :car, name: "CarType" do
  # ...
end

Declare a directive as operating an a AST node type

See directive/2

Placement

Allowed under: directive

Link to this macro parse(func_ast) View Source (macro)

Defines a parse function for a scalar type

The specified parse function is used on incoming data to transform it into an elixir datastructure.

It should return {:ok, value} or {:error, reason}

Placement

Allowed under: scalar

Link to this function record_object!(env, identifier, attrs, block) View Source
Link to this function recordable!(env, usage, kw_rules, opts \\ []) View Source
Link to this macro resolve(func_ast) View Source (macro)

Defines a resolve function for a field

Specify a 2 or 3 arity function to call when resolving a field.

You can either hard code a particular anonymous function, or have a function call that returns a 2 or 3 arity anonymous function. See examples for more information.

Note that when using a hard coded anonymous function, the function will not capture local variables.

3 Arity Functions

The first argument to the function is the parent entity.

{
  user(id: 1) {
    name
  }
}

A resolution function on the name field would have the result of the user(id: 1) field as its first argument. Top level fields have the root_value as their first argument. Unless otherwise specified, this defaults to an empty map.

The second argument to the resolution function is the field arguments. The final argument is an Absinthe.Resolution struct, which includes information like the context and other execution data.

2 Arity Function

Exactly the same as the 3 arity version, but without the first argument (the parent entity)

Placement

Allowed under: field

Examples

query do
  field :person, :person do
    resolve &Person.resolve/2
  end
end
query do
  field :person, :person do
    resolve fn %{id: id}, _ ->
      {:ok, Person.find(id)}
    end
  end
end
query do
  field :person, :person do
    resolve lookup(:person)
  end
end

def lookup(:person) do
  fn %{id: id}, _ ->
    {:ok, Person.find(id)}
  end
end
Link to this macro resolve_type(func_ast) View Source (macro)

Define a type resolver for a union or interface.

See also:

Placement

Allowed under: interface union

Examples

interface :entity do
  # ...
  resolve_type fn
    %{employee_count: _},  _ ->
      :business
    %{age: _}, _ ->
      :person
  end
end
Link to this macro scalar(identifier, attrs) View Source (macro)

Defines a scalar type

See scalar/3

Link to this macro scalar(identifier, attrs, list) View Source (macro)

Define a scalar type

A scalar type requires parse/1 and serialize/1 functions.

Placement

Top level in module.

Examples

scalar :time, description: "ISOz time" do
  parse &Timex.parse(&1.value, "{ISOz}")
  serialize &Timex.format!(&1, "{ISOz}")
end
Link to this macro serialize(func_ast) View Source (macro)

Defines a serialization function for a scalar type

The specified serialize function is used on outgoing data. It should simply return the desired external representation.

Placement

Allowed under: scalar

Link to this macro trigger(mutations, attrs) View Source (macro)

Set a trigger for a subscription field.

It accepts one or more mutation field names, and can be called more than once.

mutation do
  field :gps_event, :gps_event
  field :user_checkin, :user
end
subscription do
  field :location_update, :user do
    arg :user_id, non_null(:id)

    config fn args, _ ->
      {:ok, topic: args.user_id}
    end

    trigger :gps_event, topic: fn event ->
      event.user_id
    end

    trigger :user_checkin, topic: fn user ->
      [user.id, user.parent_id]
    end
  end
end

Trigger functions are only called once per event, so database calls within them do not present a significant burden.

See the subscription/2 macro docs for additional details

Defines the types possible under a union type

See union/3

Placement

Allowed under: union

Link to this macro union(identifier, attrs \\ [], list) View Source (macro)

Defines a union type

See Absinthe.Type.Union

Placement

Top level in module.

Examples

union :search_result do
  description "A search result"

  types [:person, :business]
  resolve_type fn
    %Person{}, _ -> :person
    %Business{}, _ -> :business
  end
end
Link to this macro value(identifier, raw_attrs \\ []) View Source (macro)

Defines a value possible under an enum type

See enum/3

Placement

Allowed under: enum