What is the test for establishing a proper factual foundation in a Charter challenge?

The respondents argued at the hearing that the petitioner relied on hypothesis and argument as the basis for his constitutional challenge. They referred to Danson v. Ontario (Attorney General), 1990 CanLII 93 (SCC), [1990] 2 S.C.R. 1086 for the proposition that the proper factual foundation must exist before determining if legislation infringes the Charter, particularly when it is the effect, not the purpose of the legislation that is said to infringe. In Danson the court drew a distinction between two categories of facts: adjudicative facts, which concern the immediate parties, and legislative facts, which establish the purpose and background of the legislation. Adjudicative facts are specific and must be proved by admissible evidence, whereas legislative facts are more general in nature and subject to less stringent requirements for admissibility. (¶ 27 and 28).