Hooks play a vital role in the Graphweaver ecosystem, allowing you to tap into various stages of the data lifecycle and execute custom logic.

In this section, we'll dive into the hooks system and explore how you can leverage it to enhance your GraphQL API development with Graphweaver.

Understanding the Hook System

Graphweaver provides a comprehensive hook system that covers different stages of entity operations, including creation, reading, updating, and deletion.

By utilizing hooks, you can intercept and manipulate data before and after these operations, enabling you to implement custom business rules, apply validations, trigger side effects, or integrate with external systems.

Types of Hooks

Let's explore an example that shows all the hooks in use within a Task entity:

@Entity('Task', {
	provider: taskProvider
})
export class Task extends GraphQLEntity<OrmTask> {
	public dataEntity!: OrmTask;

	@Field(() => ID)
	id!: string;

	@Field(() => String)
	description!: string;

	@RelationshipField<Task>(() => User, { id: 'userId' })
	user!: User;

	@RelationshipField<Tag>(() => [Tag], { relatedField: 'tasks' })
	tags!: Tag[];

	// The hooks below are not in use (and are not required when creating an entity)
	// They are included here as an example of how to use them
	@Hook(HookRegister.BEFORE_CREATE)
	async beforeCreate(params: CreateOrUpdateHook) {
		return params;
	}
	@Hook(HookRegister.AFTER_CREATE)
	async afterCreate(params: CreateOrUpdateHook) {
		return params;
	}
	@Hook(HookRegister.BEFORE_READ)
	async beforeRead(params: ReadHook) {
		return params;
	}
	@Hook(HookRegister.AFTER_READ)
	async afterRead(params: ReadHook) {
		return params;
	}
	@Hook(HookRegister.BEFORE_UPDATE)
	async beforeUpdate(params: CreateOrUpdateHook) {
		return params;
	}
	@Hook(HookRegister.AFTER_UPDATE)
	async afterUpdate(params: CreateOrUpdateHook) {
		return params;
	}
	@Hook(HookRegister.BEFORE_DELETE)
	async beforeDelete(params: DeleteHook) {
		return params;
	}
	@Hook(HookRegister.AFTER_DELETE)
	async afterDelete(params: DeleteHook) {
		return params;
	}
}

In this example, we define hooks for various stages of the entity's lifecycle, such as BEFORE_CREATE, AFTER_CREATE, BEFORE_READ, AFTER_READ, BEFORE_UPDATE, AFTER_UPDATE, BEFORE_DELETE, and AFTER_DELETE.

None of the hooks actually are changing the response but they do show you how to implement them in your own entities.

Other Syntaxes Available

In addition to writing class methods as above, you can also write functions separately and then attach them to the entity, using either the @Entity decorator or the @Hook decorator, for example: