php - Services not loaded at Resources/config/services.yml, why? -

i'm running issue here , don't know why or failing, perhaps miss configuration or so, anyway, have code @ dependencyinjection\appextension.php file:

use symfony\component\dependencyinjection\containerbuilder; use symfony\component\config\filelocator; use symfony\component\httpkernel\dependencyinjection\extension; use symfony\component\dependencyinjection\loader;  class appextension extends extension {     /**      * {@inheritdoc}      */     public function load(array $configs, containerbuilder $container)     {         $configuration = new configuration();         $config = $this->processconfiguration($configuration, $configs);          $loader = new loader\yamlfileloader($container, new filelocator(__dir__.'/../resources/config'));         $loader->load('services.yml');     } } 

then @ resources/config/services.yml have this:

services:     pdone.twig.extension:         class: groupdca\pdonebundle\extension\pdonetwigextension         tags:             -  { name: twig.extension } 

for reason isn't working. mean got error:

the filter "empty" not exist in pdonebundle::pdone.html.twig @ line 1

now if move services definition config/config.yml got error instead:

compile error: cannot use isset() on result of expression (you can use "null !== expression" instead)

which makes me think bundle not going through dependecyinjection, missing here? why different errors?

1) did add bundle appkernel?

2) not sure, think must follow naming convention of extension class:

• bundle's root directory should contain dependencyinjection directory
• within dependencyinjection, extension class should named <bundle>extension, without "bundle" suffix. pdooneextension in case.