GQLFieldProvider (Providence Utils : GraphQL 2.3.0 API)

Type Parameters:

Message - The message type.

All Known Implementing Classes:

FieldFieldProvider, InputValueFieldProvider, TypeFieldProvider
```
public interface GQLFieldProvider<Message extends net.morimekta.providence.PMessage<Message>>
```
Interface for functionality that provide field values based on a source message and a GQL field.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`net.morimekta.providence.descriptor.PMessageDescriptor<Message>`	`getDescriptor()`	Get the type descriptor this mutator is for.
`java.util.Collection<net.morimekta.providence.descriptor.PField<Message>>`	`getFields()`	Get the set of fields that can be mutated with this mutator.
`java.lang.Object`	`provide(Message message, net.morimekta.providence.descriptor.PField<Message> field, GQLField selection)`	Mutate the message according to the field selection.

- Method Detail
  - getDescriptor
```
net.morimekta.providence.descriptor.PMessageDescriptor<Message> getDescriptor()
```
    Get the type descriptor this mutator is for. This may be an interface type. Only used for error messages. This type must be indicative of the fields accepted by the provider.
    
    Returns:
    
    The message type being mutated.
  - getFields
```
@Nonnull
java.util.Collection<net.morimekta.providence.descriptor.PField<Message>> getFields()
```
    Get the set of fields that can be mutated with this mutator.
    
    Returns:
    
    Collection of mutating fields.
  - provide
```
java.lang.Object provide(@Nonnull
                         Message message,
                         @Nonnull
                         net.morimekta.providence.descriptor.PField<Message> field,
                         @Nonnull
                         GQLField selection)
```
    Mutate the message according to the field selection. The field selection will represent a single field in the base message, and will be called for each requested field.
    
    Parameters:
    
    message - The base message builder to be mutated.
    
    field - The source field requested.
    
    selection - The field selection to be filled or changed.
    
    Returns:
    
    The mutated value for the field.