How to Sort Categories¶

Sorting of categories may become challenging with an increasing number of categories. This article will help you understand the basic approach to category sorting from different perspectives (sorting in admin, adding a new category, complete import).

Sorting in administration¶

In administration is leveraged the use of nestedSortable jQuery plugin which provides a complete calculated nested set model and this model is updated entirely after category sorting is saved. This approach proved to be the best for many categories while does not impact the performance of the small data set. You can take a look at the Shopsys\FrameworkBundle\Model\Category\CategoryFacade::reorderByNestedSetValues() method for details.

Reorder the whole tree in your code¶

Whenever you need to reorder the whole tree, and you have the complete data, you can call CategoryFacade::reorderByNestedSetValues() method which accepts a complete calculated nested set model in the following format

[
    [
        'id' => 2,
        'parent_id' => null,
        'depth' => 0,
        'left' => 1,
        'right' => 14,
    ],
    [
        'id' => 3,
        'parent_id' => 2,
        'depth' => 1,
        'left' => 2,
        'right' => 3,
    ],
    // ...
]

Usually, you don't have a complete nested set model, but it's much easier to obtain a sorted adjacency list (for example, from the information system). In that case, it's possible to use Shopsys\FrameworkBundle\Model\Category\CategoryNestedSetCalculator::calculateNestedSetFromAdjacencyList() helper method to calculate the complete nested set model.

Usage is pretty straightforward. The desired category tree structure is following (each node already contain computed left and right attribute for better understanding)

We can easily obtain sorted adjacency list from a data source

$parentIdByCategoryId = [
    2 => null,
    3 => 2,
    4 => 2,
    5 => 4,
    6 => 4,
    7 => 2,
    8 => 7,
    9 => null,
    11 => 9,
    10 => null,
    12 => null,
];

At this point we pass this data to previously mentioned helper method and sort the whole tree

use Shopsys\FrameworkBundle\Model\Category\CategoryNestedSetCalculator;

$categoriesOrderingData = CategoryNestedSetCalculator::calculateNestedSetFromAdjacencyList($parentIdByCategoryId);

$this->categoryFacade->reorderByNestedSetValues($categoriesOrderingData);

Add a new category programmatically¶

When you're adding a complete new category, you usually don't need to sort the whole tree again.
You can leverage the fact the CategoryRepository extends the NestedTreeRepository, so you have really helpful methods at your disposal to place a category to first or last place, or after a specific other category.

For the full list, check out the official documentation

Import categories¶

If you're interested to know the best practices about importing categories, you can take a look at the import categories cookbook.

When things go wrong¶

It is possible that the category nested set became corrupted. Either intentionally (import directly to the database) or by mistake.

In that case, you can run following command to recalculate the whole nested set

php bin/console shopsys:categories:recalculate

The tree is recalculated only when corrupted, so you don't need to worry about your data.