PHPkeywords in XML

PHPKeywords in XML

By default, ``true``, ``false`` and ``null`` in XML are converted to the PHP

To disable thisbehaviour, use the ``string`` type:

To disable thisbehavior, use the ``string`` type:

..code-block::xml

This is not available for Yaml and PHP, because they already have built-in

support for the PHP keywords.

A parameter can also reference to a service. While doing so, it specifies an

invalid behaviour.

You can of course also reference services, which looks a bit different in

each format. You can configure the behavior if the referenced service does

not exist. By default, an exception is thrown when a non-existent service

is referenced.

Yaml

Start the string with ``@``, ``@@`` or ``@?`` to reference a service in Yaml.

Start the string with ``@`` or ``@?`` to reference a service in Yaml.

* ``@mailer`` referencestothe ``mailer`` service. If the service does not

* ``@mailer`` references the ``mailer`` service. If the service does not

exists, an exception will be thrown;

* ``@?mailer`` referencestothe ``mailer`` service. If the service does not

* ``@?mailer`` references the ``mailer`` service. If the service does not

exists, it will be ignored;

Xml

In XML, use the ``service`` type. The behaviour if the service does not exists

can be specified using the ``on-invalid`` argument (it can be set to ``null``

to return ``null`` or ``ignored`` to let the container ignore the error, if

not specified it throws an exception).

In XML, use the ``service`` type. The behavior if the service does not exists

can be specified using the ``on-invalid`` argument. By default, an exception

is thrown. Valid values for ``on-invalid`` are ``null`` (uses ``null`` in place

of the missing service) or ``ignored`` (very similar, except if used on a

method call, the method call is removed).

Php

In PHP, you can use the

:class:`Symfony\\Component\\DependencyInjection\\Reference` class to reference

a service.

a service. The invalid behavior is configured using the second constructor

argument and constants from

:class:`Symfony\\Component\\DependencyInjection\\ContainerInterface`.