# addTo*

## Purpose

Adds a domain class relationship for one-to-many or many-to-many relationship, where the relationship is indicated by the property used as the suffix to the method.

## Examples

    def fictBook = new Book(title:"IT")
    def nonFictBook = new Book(title:"On Writing: A Memoir of the Craft")
    def a = new Author(name:"Stephen King")
                 .addToFiction(fictBook)       // 'fiction' is name of relationship property
                 .addToNonFiction(nonFictBook) // 'nonFiction' is name of relationship property
                 .save()

## Description

The `addTo*` method is a dynamic method that uses an association to automatically add instances to the association. It also automatically configures bi-directional relationship so that both sides o the relationship have been set.

The method expects an instance of the associated class:

    def fictBook = new Book(title:"IT")
    def nonFictBook = new Book(title:"On Writing: A Memoir of the Craft")
    def a = new Author(name:"Stephen King")
                 .addToFiction(fictBook)       // 'fiction' is name of relationship property
                 .addToNonFiction(nonFictBook) // 'nonFiction' is name of relationship property
                 .save()

Or a map, in which case it auto-instantiates an instance of the associated class:

    def a = new Author(name:"Stephen King")
                 .addToFiction(title:"IT")
                 .addToNonFiction(title:"On Writing: A Memoir of the Craft")
                 .save()