symfony - Adding a block into Sonata Admin Interface -

i trying add block admin dashboard, using sonataadminbundle. tried follow directives written here in first answer : how add custom link or button sonataadminbundle dashboard in symfony2

but have problem in blockservice class.

the code follow :

namespace appbundle\block;  use symfony\component\httpfoundation\response; use sonata\adminbundle\form\formmapper; use sonata\corebundle\validator\errorelement; use sonata\blockbundle\model\blockinterface; use sonata\blockbundle\block\baseblockservice;  class invitationblockservice extends baseblockservice {     public function getname()     {         return 'invitation manager';     }      public function getdefaultsettings() {     return array(); }  public function validateblock(errorelement $errorelement, blockinterface $block) { }  public function buildeditform(formmapper $formmapper, blockinterface $block) { }  public function execute(blockinterface $block, response $response = null) {     // merge settings     $settings = array_merge($this->getdefaultsettings(), $block->getsettings());      return $this->renderresponse('institutostoriconewsletterbundle:block:block_invitation.html.twig', array(         'block'     => $block,         'settings'  => $settings     ), $response); } 

}

but have compilation error on validatblock, buildedittform , execute method :

declaration must compatible blockserviceinterface->validateblock(errorelement : \sonata\adminbundle>\validator\errorelement, block : \sonata\blockbundle\model\blockinterface) class hierarchy checks: abstract methods implementation, implementing/overriding method compatibility super declaration. violations result in php fatal errors. it's not recommended disable or suppress inspection.

do have idea ?

thank reading.

i found cause of problem : had self-update composer.

it looks composer old, , did not fetch every files or dependancy needed.

so, composer self-update saved me.