In example illustration of how to use a base query function to generate a filtered and sorted query without repeating code for each function.

controller.php

<?php

public function index()
{
    if(Input::get('sort')) {
        $this->offices->sort(Input::get('sort'), Input::get('direction'));
    }
    $offices = $this->offices->all();
    return View::make('app.offices.list', compact('offices'));
}

repository.php

<?php

class DBOffice implements OfficeInterface
{

    protected $offices;

    protected $filter;

    protected $defaultSort = array(
        'type'  => 'asc',
        'name'  => 'asc'
    );
    
    protected $currentSort = array();

    protected $filterEnabled = true;

    public function __construct(Office $offices, UserAccessFilterInterface $filter)
    {
        $this->offices = $offices;

        $this->filter = $filter;

        $this->currentSort = $this->defaultSort;
    }

    protected function getBaseQuery($sort = true)
    {
        $query = $this->offices->newQuery();
        if($this->filterEnabled && !$this->filter->isAdmin()) {
            $id = $this->filter->getCurrentUserId();
            $query->where(function($q) use ($id) {
                $q->where('user_id', $id)->orWhereNull('user_id');
            });
        }
        if($sort) {
            $this->addSortingToQuery($query);
        }
        return $query;
    }
    
    protected function addSortingToQuery($query)
    {
        foreach($this->currentSort as $field => $direction) {
            $query->orderBy($field, $direction);
        }
    }
    
    public function sort($field, $direction = 'asc')
    {
        array_unshift($this->currentSort, array($field => $direction));
        
        return $this;
    }
    
    public function all($paginate = true)
    {
        $query = $this->getBaseQuery();
        return ($paginate) ? $query->paginate($this->perPage) : $query->get();
    }
    
    public function findById($id)
    {
        return $this->getBaseQuery(false);
            ->whereId($id)
            ->first();
    }
    
}