Response for a class (RFC) measure

[andrii-pukhalevych]

Response for a class (RFC) measure

[kylekatarnls]

You can check the code for other metrics https://github.com/pdepend/pdepend/tree/master/src/main/php/PDepend/Metrics/Analyzer

And you can propose a new one here with a pull-request.

[tvbeek]

Hello @andrii-pukhalevych

To be honest I don't understand your question, can you explain it in more detail?

[andrii-pukhalevych]

Response for a class (RFC) is a number of methods in class + number of unique method calls of another classes.

The metric called the response for a class (RFC) measures the number of different methods that can be executed when an object of that class receives a message (when a method is invoked for that object). Ideally, we would want to find for each method of the class, the methods that class will call, and repeat this for each called method, calculating what is called the transitive closure of the method's call graph. This process can however be both expensive and quite inaccurate. In ckjm, we calculate a rough approximation to the response set by simply inspecting method calls within the class's method bodies. The value of RFC is the sum of number of methods called within the class's method bodies and the number of class's methods. This simplification was also used in the 1994 Chidamber and Kemerer description of the metrics.

[kylekatarnls]

Hello, here is how you can get the number of public methods of a class:

function getNumberOfPublicMethods(\PDepend\Source\AST\ASTClass $class): int
{
    return count(array_filter($class->getAllMethods(), function (\PDepend\Source\AST\ASTMethod $method) {
        return $method->isPublic();
    }));
}

Which is a relevant proxy for response for a class in PHP in my opinion. I think that's what other analyzers do.