Custom query operators support

[marcojetson]

Provides a way to add custom query operators.
Supports either a callback or a class string implementing callable.

public static void \Spot\Query::addWhereOperator ( string $operator, callable|string $action )

Adds a new operator to the query's where parser.

Parameters

operator

Operator token

action

Operator handler. Either a callable or a class name implementing __invoke.

Errors/Exceptions

Emits Spot\Exception if the operator already exists.

Examples

<?php

// using a callback
\Spot\Query::addWhereOperator(':json_exists', function ($builder, $column, $value) {
    return 'jsonb_exists(' . $column . ', ' . $builder->createPositionalParameter($value) . ')';
});

// using a class
class JsonEquals
{
    public function __invoke(Doctrine\DBAL\Query\QueryBuilder $builder, $column, $value)
    {
        return $column . '::text = ' . $builder->createPositionalParameter($value);
    }
}

\Spot\Query::addWhereOperator(':json_equals', JsonEquals::class);

[nebulousGirl]

Just curious. Why are you passing a class string instead of a new instance of the class in the __invoke example?

[marcojetson]

It will also work if you pass a new instance, but I wanted to add a class reference to the example.
Reasons to allow a class references are:

• Being able to specify defaults in Spot\Query::$_operators
• Lazy instantiation, makes no sense to create every operator instance on every request

In addition \Spot\Query is using flyweight pattern and sharing operator instances across Query instances.

[vlucas]

Looks good. Thanks for the effort on this @marcojetson.