View Source Absinthe.Resolution (absinthe v1.7.8)
Information about the current resolution. It is created by adding field specific
information to the more general %Absinthe.Blueprint.Execution{} struct.
In many ways like the %Conn{} from Plug, the %Absinthe.Resolution{} is the
piece of information that passed along from middleware to middleware as part of
resolution.
Contents
:adapter- The adapter used for any name conversions.:definition- The Blueprint definition for this field.:context- The context passed toAbsinthe.run.:root_value- The root value passed toAbsinthe.run, if any.:parent_type- The parent type for the field.:private- Operates similarly to the:privatekey on a%Plug.Conn{}and is a place for libraries (and similar) to store their information.:schema- The current schema.:source- The resolved parent object; source of this field.
When a %Resolution{} is accessed via middleware, you may want to update the
context (e.g. to cache a dataloader instance or the result of an ecto query).
Updating the context can be done simply by using the map updating syntax (or
Map.put/3):
%{resolution | context: new_context}
# OR
Map.put(resolution, :context, new_context)To access the schema type for this field, see the definition.schema_node.
Summary
Types
The arguments that are passed from the schema. (e.g. id of the record to be fetched)
Functions
TODO: Deprecate
Get the current path.
Get the child fields under the current field.
Get the child fields under the current field.
Handy function for applying user function result tuples to a resolution struct
Types
The arguments that are passed from the schema. (e.g. id of the record to be fetched)
@type field_state() :: :unresolved | :resolved | :suspended
@type source() :: any()
@type t() :: %Absinthe.Resolution{ acc: %{required(any()) => any()}, adapter: Absinthe.Adapter.t(), arguments: arguments(), context: map(), definition: Absinthe.Blueprint.node_t(), errors: [term()], extensions: %{required(any()) => any()}, fields_cache: term(), fragments: [Absinthe.Blueprint.Document.Fragment.Named.t()], middleware: term(), parent_type: Absinthe.Type.t(), path: term(), private: term(), root_value: any(), schema: Absinthe.Schema.t(), source: source(), state: field_state(), value: term() }
Functions
TODO: Deprecate
Get the current path.
Each Absinthe.Resolution struct holds the current result path as a list of
blueprint nodes and indices. Usually however you don't need the full AST list
and instead just want the path that will eventually end up in the result.
For that, use this function.
Examples
Given some query:
{users { email }}If you called this function inside a resolver on the users email field it returns a value like:
resolve fn _, _, resolution ->
Absinthe.Resolution.path(resolution) #=> ["users", 5, "email"]
endIn this case 5 is the 0 based index in the list of users the field is currently
at.
Get the child fields under the current field.
See project/2 for details.
Get the child fields under the current field.
Example
Given a document like:
{ user { id name }}field :user, :user do
resolve fn _, info ->
child_fields = Absinthe.Resolution.project(info) |> Enum.map(&(&1.name))
# ...
end
endchild_fields will be ["id", "name"].
It correctly handles fragments, so for example if you had the document:
{
user {
... on User {
id
}
... on Named {
name
}
}
}you would still get a nice and simple child_fields that was ["id", "name"].
Handy function for applying user function result tuples to a resolution struct
User facing functions generally return one of several tuples like {:ok, val}
or {:error, reason}. This function handles applying those various tuples
to the resolution struct.
The resolution state is updated depending on the tuple returned. :ok and
:error tuples set the state to :resolved, whereas middleware tuples set it
to :unresolved.
This is useful for middleware that wants to handle user facing functions, but does not want to duplicate this logic.