<?xml version="1.0"?>
<container xmlns="http://symfony.com/schema/dic/services"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
    <services>
        <service id="elnur_bootstrap.button_type_extension"
                 class="Elnur\Bundle\BootstrapBundle\Form\Extension\ButtonTypeExtension">
            <tag name="form.type_extension" alias="button"/>
        </service>
        <service id="elnur_bootstrap.group_type_extension"
                 class="Elnur\Bundle\BootstrapBundle\Form\Extension\GroupTypeExtension">
            <tag name="form.type_extension" alias="form"/>
        </service>
    </services>
</container>

<?xml version="1.0"?>
<container xmlns="http://symfony.com/schema/dic/services"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <parameters>
        <parameter key="elnur_bootstrap.button_type_extension.class">Elnur\Bundle\BootstrapBundle\Form\Extension\ButtonTypeExtension</parameter>
        <parameter key="elnur_bootstrap.group_type_extension.class">Elnur\Bundle\BootstrapBundle\Form\Extension\GroupTypeExtension</parameter>
    </parameters>

    <services>
        <service id="elnur_bootstrap.button_type_extension" class="%elnur_bootstrap.button_type_extension.class%">
            <tag name="form.type_extension" alias="button"/>
        </service>
        <service id="elnur_bootstrap.group_type_extension" class="%elnur_bootstrap.group_type_extension.class%">
            <tag name="form.type_extension" alias="form"/>
        </service>
    </services>
</container>

Make form type extension classes overridable using parameters
Make form type extension classes overridable using parameters
