editSemester() {
      db
        .collection("semesters")
        .where(FieldPath.documentid(), "==", this.editSemId)
        .get()
        .then(querySnapshot => {
          querySnapshot.forEach(doc => {
            doc
              .set({
                title: this.editingSemester.title
              })
              .then(
                swal({
                  title: "Du har redigeret et semester!",
                  icon: "success",
                  timer: 1500,
                  button: "OK"
                })
              );
          });
          this.getSemesters();
          this.cancel();
        })
        .catch(function(error) {
          console.log(error.message);
        });
    },