ShareLater functionality

app\Providers\ViewServiceProvider.php

<?php

//

    public function boot()
    {
        View::shareLater('user', function () {
            return auth()->user();
        });
    }

Illuminate\Contracts\View\Shareable.php

<?php

namespace Illuminate\Contracts\View;

interface Shareable
{
    /**
     * Resolve the shareable data.
     *
     * @return  mixed
     */
    public function share();
}

Illuminate\View\Factory.php

<?php

use Illuminate\View\ShareLater;

//

    /**
     * Share a callback to be resolved later.
     *
     * @param   string  $key
     * @param   callable|string  $callback
     * @param   boolean  $once
     * @return  void
     */
    public function shareLater($key, $callback, $once = true)
    {
        $this->share($key, new ShareLater($this->container, $callback, $once));
    }

Illuminate\View\ShareLater.php

<?php

namespace Illuminate\View;

use Illuminate\Contracts\View\Shareable;

class ShareLater implements Shareable
{
    /**
     * The IoC container instance.
     *
     * @var \Illuminate\Contracts\Container\Container
     */
    protected $container;

    /**
     * The shared callback that will be resolved when the data is needed.
     *
     * @var  callable|string
     */
    protected $shared;

    /**
     * Whether the callback should be resolved only once.
     *
     * @var  bool
     */
    protected $once;

    /**
     * Has the callback been resolved.
     *
     * @var  boolean
     */
    protected $resolved = false;

    /**
     * The result of calling the callback.
     *
     * @var  mixed
     */
    protected $result;

    /**
     * Create a new ShareLater instance.
     *
     * @param  \Illuminate\Contracts\Container\Container  $container
     * @param  callable|string  $shared
     * @param  bool  $once
     * @return void
     */
    public function __construct($container, $shared, $once = true)
    {
        $this->container = $container;
        $this->shared = $shared;
        $this->once = $once;
    }

    /**
     * Return the resolved shared data.
     *
     * @return  mixed
     */
    public function share()
    {
        if ($this->once && $this->resolved) {
            return $this->result;
        }

        return tap($this->container->call($this->shared), function ($result) {
            $this->result = $result;
            $this->resolved = true;
        });
    }
}

Illuminate\View\View.php

<?php

use Illuminate\Contracts\View\Shareable;

//

    public function gatherData()
    {
        $data = array_merge($this->factory->getShared(), $this->data);

        foreach ($data as $key => $value) {
            if ($value instanceof Renderable) {
                $data[$key] = $value->render();
            } elseif ($value instanceof Shareable) {
                $data[$key] = $value->share();
            }
        }

        return $data;
    }