HasOne.php

TLDR

This file contains the HasOne class, which is a subclass of HasOneOrMany and implements the SupportsPartialRelations interface. The class is used to define a one-to-one relationship between two models in the Laravel Eloquent ORM.

Methods

getResults

This method retrieves the results of the relationship.

initRelation

This method initializes the relation on a set of models.

match

This method matches the eagerly loaded results to their parents.

getRelationExistenceQuery

This method adds the constraints for an internal relationship existence query.

addOneOfManySubQueryConstraints

This method adds constraints for an inner join subselect for one of many relationships.

getOneOfManySubQuerySelectColumns

This method gets the columns that should be selected by the one of many subquery.

addOneOfManyJoinSubQueryConstraints

This method adds join query constraints for one of many relationships.

newRelatedInstanceFor

This method creates a new related instance for the given model.

getRelatedKeyFrom

This method gets the value of the model's foreign key.

Classes

There are no classes in this file.

<?php

namespace Illuminate\Database\Eloquent\Relations;

use Illuminate\Contracts\Database\Eloquent\SupportsPartialRelations;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\Concerns\CanBeOneOfMany;
use Illuminate\Database\Eloquent\Relations\Concerns\ComparesRelatedModels;
use Illuminate\Database\Eloquent\Relations\Concerns\SupportsDefaultModels;
use Illuminate\Database\Query\JoinClause;

class HasOne extends HasOneOrMany implements SupportsPartialRelations
{
    use ComparesRelatedModels, CanBeOneOfMany, SupportsDefaultModels;

    /**
     * Get the results of the relationship.
     *
     * @return mixed
     */
    public function getResults()
    {
        if (is_null($this->getParentKey())) {
            return $this->getDefaultFor($this->parent);
        }

        return $this->query->first() ?: $this->getDefaultFor($this->parent);
    }

    /**
     * Initialize the relation on a set of models.
     *
     * @param  array  $models
     * @param  string  $relation
     * @return array
     */
    public function initRelation(array $models, $relation)
    {
        foreach ($models as $model) {
            $model->setRelation($relation, $this->getDefaultFor($model));
        }

        return $models;
    }

    /**
     * Match the eagerly loaded results to their parents.
     *
     * @param  array  $models
     * @param  \Illuminate\Database\Eloquent\Collection  $results
     * @param  string  $relation
     * @return array
     */
    public function match(array $models, Collection $results, $relation)
    {
        return $this->matchOne($models, $results, $relation);
    }

    /**
     * Add the constraints for an internal relationship existence query.
     *
     * Essentially, these queries compare on column names like "whereColumn".
     *
     * @param  \Illuminate\Database\Eloquent\Builder  $query
     * @param  \Illuminate\Database\Eloquent\Builder  $parentQuery
     * @param  array|mixed  $columns
     * @return \Illuminate\Database\Eloquent\Builder
     */
    public function getRelationExistenceQuery(Builder $query, Builder $parentQuery, $columns = ['*'])
    {
        if ($this->isOneOfMany()) {
            $this->mergeOneOfManyJoinsTo($query);
        }

        return parent::getRelationExistenceQuery($query, $parentQuery, $columns);
    }

    /**
     * Add constraints for inner join subselect for one of many relationships.
     *
     * @param  \Illuminate\Database\Eloquent\Builder  $query
     * @param  string|null  $column
     * @param  string|null  $aggregate
     * @return void
     */
    public function addOneOfManySubQueryConstraints(Builder $query, $column = null, $aggregate = null)
    {
        $query->addSelect($this->foreignKey);
    }

    /**
     * Get the columns that should be selected by the one of many subquery.
     *
     * @return array|string
     */
    public function getOneOfManySubQuerySelectColumns()
    {
        return $this->foreignKey;
    }

    /**
     * Add join query constraints for one of many relationships.
     *
     * @param  \Illuminate\Database\Query\JoinClause  $join
     * @return void
     */
    public function addOneOfManyJoinSubQueryConstraints(JoinClause $join)
    {
        $join->on($this->qualifySubSelectColumn($this->foreignKey), '=', $this->qualifyRelatedColumn($this->foreignKey));
    }

    /**
     * Make a new related instance for the given model.
     *
     * @param  \Illuminate\Database\Eloquent\Model  $parent
     * @return \Illuminate\Database\Eloquent\Model
     */
    public function newRelatedInstanceFor(Model $parent)
    {
        return $this->related->newInstance()->setAttribute(
            $this->getForeignKeyName(), $parent->{$this->localKey}
        );
    }

    /**
     * Get the value of the model's foreign key.
     *
     * @param  \Illuminate\Database\Eloquent\Model  $model
     * @return mixed
     */
    protected function getRelatedKeyFrom(Model $model)
    {
        return $model->getAttribute($this->getForeignKeyName());
    }
}