I want to use some feature engineering steps inside a cross-validation loop. For example, I want to evaluate the combination of a PCA (preprocessing) and k-NN (modeling) algorithm. In order to do so, I use the X-Validation operator. However, as PCA changes the features that are available in the original dataset, I cannot in the testing simply connect the model and test set input to the "Apply Model" operator. I probably also need to do something with the preprocessing method.
I can see PCA has a preprocessing model as output, is that what I should use to overcome thing problem? If yes, how?