Class BelongsTo

lib/associations/belongs-to.js:16–249

* One-to-one association * * In the API reference below, add the name of the association to the method, e.g. for `User.belongsTo(Project)` the getter will be `user.getProject()`. * * @see {@link Model.belongsTo}

 * @see {@link Model.belongsTo}
 */
class BelongsTo extends Association {
  constructor(source, target, options) {
    super(source, target, options);

    this.associationType = 'BelongsTo';
    this.isSingleAssociation = true;
    this.foreignKeyAttribute = {};

    if (this.as) {
      this.isAliased = true;
      this.options.name = {
        singular: this.as
      };
    } else {
      this.as = this.target.options.name.singular;
      this.options.name = this.target.options.name;
    }

    if (_.isObject(this.options.foreignKey)) {
      this.foreignKeyAttribute = this.options.foreignKey;
      this.foreignKey = this.foreignKeyAttribute.name || this.foreignKeyAttribute.fieldName;
    } else if (this.options.foreignKey) {
      this.foreignKey = this.options.foreignKey;
    }

    if (!this.foreignKey) {
      this.foreignKey = Utils.camelize(
        [
          this.as,
          this.target.primaryKeyAttribute
        ].join('_')
      );
    }

    this.identifier = this.foreignKey;
    if (this.source.rawAttributes[this.identifier]) {
      this.identifierField = this.source.rawAttributes[this.identifier].field || this.identifier;
    }

    if (
      this.options.targetKey
      && !this.target.rawAttributes[this.options.targetKey]
    ) {
      throw new Error(`Unknown attribute "${this.options.targetKey}" passed as targetKey, define this attribute on model "${this.target.name}" first`);
    }

    this.targetKey = this.options.targetKey || this.target.primaryKeyAttribute;
    this.targetKeyField = this.target.rawAttributes[this.targetKey].field || this.targetKey;
    this.targetKeyIsPrimary = this.targetKey === this.target.primaryKeyAttribute;
    this.targetIdentifier = this.targetKey;

    this.associationAccessor = this.as;
    this.options.useHooks = options.useHooks;

    // Get singular name, trying to uppercase the first letter, unless the model forbids it
    const singular = _.upperFirst(this.options.name.singular);

    this.accessors = {