Building Custom Query Filter Classes

For advanced users, the REST API's framework allows for custom query filter classes to be added using PHP. To add a custom query filter class, extend the \RESTAPI\Core\QueryFilter class and implement the evaulate method. This method takes the targetted field's value and a filter value and returns a boolean value indicating if the field matches the filter. Below is an example of a custom QueryFilter class:

<?php

namespace RESTAPI\QueryFilters;

require_once 'RESTAPI/autoloader.inc';

use RESTAPI\Core\QueryFilter;

class MyCustomQueryFilter extends QueryFilter {
    # Sets the name of the query filter that will be used in the query string
    public string $name = 'customfilter';

    # Sets the logic for the query filter. In this example, we are checking if the field value is equal to the filter value.
    public function evaluate(mixed $field_value, mixed $filter_value): bool {
        return $field_value == $filter_value;
    }
}

Once your custom QueryFilter class is created, simply place it at /usr/local/pkg/RESTAPI/QueryFilters/MyCustomQueryFilter.inc and it will automatically become an available query filter that can be used by the REST API.

An example usage of this custom query filter would be /api/v2/firewall/rules?fieldname__customfilter=filter_value.

Examples

You can find examples of fully implemented QueryFilter classes in the PHP reference. Select the QueryFilter class you are interested in to view the class's PHPDoc documentation, and then click on the <> symbol next to the class name to view the class's source code.