In City of Hanford v. Superior Court (1989) 208 Cal. App. 3d 580, environmental groups challenged a city's approval of construction of a power plant by a private power company; the trial court entered judgment in favor of the city and real party in interest power company; while the plaintiffs' appeal was pending, the power company sought and was granted leave to file a cross-complaint against city, in order to challenge a newly enacted moratorium ordinance prohibiting permits for power plants. The court of appeal in City of Hanford reversed the order permitting the filing of the cross complaint; because the cross-complaint was not against the plaintiffs environmental groups, but against city, it was not a compulsory cross-complaint; rather, it was "sufficiently independent of the underlying complaint to avoid the one final judgment rule," and was "best treated as a separate action." (208 Cal. App. 3d 580, 588.) Thus, "no purpose is served by injecting the claims of the cross-complaint into the underlying proceeding." (Ibid.) Moreover, "allowing a party to assert cross-complaints while a case is pending on appeal, could create chaos with the appellate process. The purpose of the rule depriving the trial court of jurisdiction pending appeal in civil actions is to protect the jurisdiction of the appellate court. The rule prevents the trial court from rendering the appeal futile by changing the judgment into something different from the judgment appealed. . . . A cross-complaint should not be permitted to circumvent the appellate rights of other parties by injecting additional claims into the lawsuit while the case is pending on appeal." (Ibid.)