absinthe v1.2.6 Absinthe.Resolution.Plugin behaviour

Defines Resolution Plugin Behaviour

Plugins enable custom resolution behaviour on a field. A plugin is activated on field if its resolution function returns the following tuple instead of one of the usual {:ok, value} or {:error, reason} tuples:

{:plugin, NameOfPluginModule, term}

Often a plugin will provide a helper function to return this, see Absinthe.Resolution.Helpers.async/1 for an example.

Plugins use the information placed in the third element of the plugin tuple along with values in the resolution accumulator to perform whatever logic they need.

NOTE: All plugins that will be used must be listed on the schema.

The Resolution Accumulator

The resolution accumulator is just a map that is carried through the resolution process. The Async plugin uses it to flag whether or not a field has been executed asynchronously, which indicates that another resolution pass is needed to await that field. The Batch plugin uses it to hold all the information that will be used for batching.

Summary

Types

t()

Any module that implements this behaviour

Functions

defaults()

The default list of resolution plugins

Callbacks

after_resolution(resolution_acc)

Function called after the execution of a resolution phase

before_resolution(resolution_acc)

Function called prior to the execution of a resolution phase

init(any, arg1)

Called after a field invokes the plugin

pipeline(next_pipeline, resolution_acc)

Add any additional phases required by the plugin

Types

t()

t :: atom

Any module that implements this behaviour

Functions

defaults()

The default list of resolution plugins

Callbacks

after_resolution(resolution_acc)

after_resolution(resolution_acc :: Absinthe.Blueprint.Document.Resolution.acc) :: Absinthe.Blueprint.Document.Resolution.acc

Function called after the execution of a resolution phase.

NOTE: This function is given the full accumulator. Namespacing is suggested to avoid conflicts.

before_resolution(resolution_acc)

before_resolution(resolution_acc :: Absinthe.Blueprint.Document.Resolution.acc) :: Absinthe.Blueprint.Document.Resolution.acc

Function called prior to the execution of a resolution phase.

This allows plugins to setup any data in the resolution accumulator they may need.

NOTE: This function is given the full accumulator. Namespacing is suggested to avoid conflicts.

init(any, arg1)

init(any, Absinthe.Blueprint.Document.Resolution.acc) :: {any :: Absinthe.Blueprint.Document.Resolution.acc}

Called after a field invokes the plugin.

Resolution functions invoke a function via:

{:plugin, PluginModule, plugin_data}

The first argument to init is whatever plugin_data is. The second is the resolution accumulator.

NOTE: This function is given the full accumulator. Namespacing is suggested to avoid conflicts.

pipeline(next_pipeline, resolution_acc)

pipeline(next_pipeline :: Absinthe.Pipeline.t, resolution_acc :: Map.t) :: Absinthe.Pipeline.t

Add any additional phases required by the plugin.

Plugins may require additional resolution phases to be run. This function should use values set in the resolution accumulator whether or not additional phases are required.

NOTE: This function is given the whole pipeline to be inserted after the current phase completes.