ElementPass Class

Detailed Description

ElementPass is the simpler of the two analysis passes. It will consider every element in a file. The shouldRun() method can be used to filter out irrelevant elements, and the run() method is doing the initial work.

Common tasks suitable for an ElementPass are

• checking that properties of an Element are not combined in a nonsensical way
• validating property values (e.g. that a property takes only certain enum values)
• checking behavior dependent on an Element's parent (e.g. not using Item::width when the parent element is a Layout).

As shown in the snippet below, it is recommended to do necessary type resolution in the constructor of the ElementPass and cache it in local members, and to implement some filtering via shouldRun() to keep the static analysis performant.

 using namespace QQmlSA;
 class MyElementPass : public ElementPass
 {
     Element myType;
     public:
         MyElementPass(QQmlSA::PassManager *manager)
         : myType(resolveType("MyModule", "MyType")) {}

         bool shouldRun(const Element &element) override
         {
             return element.inherits(myType);
         }
         void run(const Element &element) override
         {
             // actual pass logic
         }
 }

ElementPasses have limited insight into how an element's properties are used. If you need that information, consider using a PropertyPass instead.