What is the syntax for sorting an Eloquent collection by multiple columns?

Question

I know that when using the query builder, it is possible to sort by multiple columns using

...orderBy(\'column1\')->orderBy(\'column2\')

Answer 1

As @derekaug mentioned, the sort method allows us to enter a custom closure for sorting the collection. But I thought his solution was somewhat cumbersome to write and it woulde be nice to have something like this:

$collection = collect([/* items */])
$sort = ["column1" => "asc", "column2" => "desc"];
$comparer = $makeComparer($sort);
$collection->sort($comparer);

In fact, this can be easily archived by the following $makeComparer wrapper to generate the compare closure:

$makeComparer = function($criteria) {
  $comparer = function ($first, $second) use ($criteria) {
    foreach ($criteria as $key => $orderType) {
      // normalize sort direction
      $orderType = strtolower($orderType);
      if ($first[$key] < $second[$key]) {
        return $orderType === "asc" ? -1 : 1;
      } else if ($first[$key] > $second[$key]) {
        return $orderType === "asc" ? 1 : -1;
      }
    }
    // all elements were equal
    return 0;
  };
  return $comparer;
};

Examples

$collection = collect([
  ["id" => 1, "name" => "Pascal", "age" => "15"],
  ["id" => 5, "name" => "Mark", "age" => "25"],
  ["id" => 3, "name" => "Hugo", "age" => "55"],
  ["id" => 2, "name" => "Angus", "age" => "25"]
]);

$criteria = ["age" => "desc", "id" => "desc"];
$comparer = $makeComparer($criteria);
$sorted = $collection->sort($comparer);
$actual = $sorted->values()->toArray();

/**
* [
*  ["id" => 5, "name" => "Hugo", "age" => "55"],
*  ["id" => 3, "name" => "Mark", "age" => "25"],
*  ["id" => 2, "name" => "Angus", "age" => "25"],
*  ["id" => 1, "name" => "Pascal", "age" => "15"],
* ];
*/

$criteria = ["age" => "desc", "id" => "asc"];
$comparer = $makeComparer($criteria);
$sorted = $collection->sort($comparer);
$actual = $sorted->values()->toArray();

/**
* [
*  ["id" => 5, "name" => "Hugo", "age" => "55"],
*  ["id" => 2, "name" => "Angus", "age" => "25"],
*  ["id" => 3, "name" => "Mark", "age" => "25"],
*  ["id" => 1, "name" => "Pascal", "age" => "15"],
* ];
*/

$criteria = ["id" => "asc"];
$comparer = $makeComparer($criteria);
$sorted = $collection->sort($comparer);
$actual = $sorted->values()->toArray();

/**
* [
*  ["id" => 1, "name" => "Pascal", "age" => "15"],
*  ["id" => 2, "name" => "Angus", "age" => "25"],
*  ["id" => 3, "name" => "Mark", "age" => "25"],
*  ["id" => 5, "name" => "Hugo", "age" => "55"],
* ];
*/

Now, since we're talking Eloquent here, chances are high that you're also using Laravel. So we might even bind the $makeComparer() closure to the IOC and resolve it from there:

// app/Providers/AppServiceProvider.php 
// in Laravel 5.1
class AppServiceProvider extends ServiceProvider
{
    /**
     * ...
     */


    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        $this->app->bind("collection.multiSort", function ($app, $criteria){
                return function ($first, $second) use ($criteria) {
                    foreach ($criteria as $key => $orderType) {
                        // normalize sort direction
                        $orderType = strtolower($orderType);
                        if ($first[$key] < $second[$key]) {
                            return $orderType === "asc" ? -1 : 1;
                        } else if ($first[$key] > $second[$key]) {
                            return $orderType === "asc" ? 1 : -1;
                        }
                    }
                    // all elements were equal
                    return 0;
                };
        });
    }
}

Now you can use it everywhere you need to like so:

$criteria = ["id" => "asc"];
$comparer = $this->app->make("collection.multiSort",$criteria);
$sorted = $collection->sort($comparer);
$actual = $sorted->values()->toArray();