I do not follow soccer but unless they have been officially eliminated, then no, absolutely its not over. Sports of all things should teach people that nothing is over if there is a chance. They are probably certainly eliminated but there is always the opportunity to shock the world and grab a piece of history.
No, the championship for Barcelona's soccer team is not over. They have Lionel Messi, one of the best soccer players in the world. Messi has proven over the years that he can score goals that look impossible, and can pull his team along with him. Barcelona has all the skill and talent needed to win the championship.
On May 6, 2015 during the UEFA Champions League semifinals Barcelona beat Bayern Munich 3-0. With only 15 minutes left in the game the score continued to be 0-0 but it was the tactics employed by Lionel Messi that turned it all around. This win allows Barcelona to advance proving the championship isn't over yet.
Barcelona has historically won over Real Sociedad, their next opponent. Barcelona also has a better record for the season, with more wins total than Real Sociedad. So even though Barcelona lost to them last year, I believe that they will overcome this year and make it one step further in the Championship.