In City of Philadelphia v. Commonwealth, 575 Pa. 542, 838 A.2d 566 (2003) our supreme court considered the scope of section 7540(a) of the Declaratory Judgments Act and held that its mandate to join as parties all those whose interests would be affected by the declaration is subject to reasonable limitations. For example, the court reasoned that in cases challenging the validity of a statute or ordinance, which, by its nature, affects the interests of large numbers of people, section 7540(a) of the Declaratory Judgments Act does not require the joinder of every party having any interest that could potentially be affected by the invalidation of the statute. The court explained that if there were such a requirement, "the valuable remedy of declaratory judgment would be rendered impractical and indeed often worthless for determining the validity of legislative enactments, either state or local, since such enactments commonly affect the interests of large numbers of people." Id. at 569, 838 A.2d at 583 (quoting Town of Blooming Grove v. City of Madison, 275 Wis. 328, 81 N.W.2d 713, 717 (Wis. 1957)). In City of Philadelphia, the City of Philadelphia (City) sought declaratory and injunctive relief against the Commonwealth, alleging that newly enacted legislation pertaining to the governance of the Pennsylvania Convention Center violated the Pennsylvania Constitution. After this court preliminarily enjoined the implementation of the challenged legislation, the Commonwealth appealed, arguing that the courts lacked subject matter jurisdiction because the City failed to join numerous indispensable parties. Id. As summarized by our supreme court, "the Commonwealth appears to contend that anyone whose interests may be affected by any aspect of the challenged legislation must be formally joined for jurisdiction to lie." Id. at 567, 838 A.2d at 581. The supreme court rejected such a broad reading of section 7540(a).