add an validate callback to Article entity with the rule : if an article is published, a publication date should be set
add an validate callback to Article entity with the rule : if an article is published, a publication date should be set

johnkrovitch/LeComptoirDeLEcureuil,johnkrovitch/LeComptoirDeLEcureuil,johnkrovitch/LeComptoirDeLEcureuil,johnkrovitch/LeComptoirDeLEcureuil