In the IU video its explained that the Input to and Output from a view to be used as a template have to be defined as Parameters with input/out/both direction for each parameter. When Instantiating this view as embedded view in another view, the output parameters from the template automatically appear in the parameter list of the parent view (e.g. isActive parameter in the above video). Whereas the input parameters to the template have to be manually added ensuring that the name matches exactly as defined in template. Then these parameters can be bound to tags directly or indirectly.
My question why can’t the input parameters to the template be automatically populated in the parameter list of the parent view as is the case with output parameters? Why they have to be manually added with exact name matching with the defined names in template? This is confusing. Intuitively all parameters of the template should automatically appear in the parent view, they should take default values when not bound to anything. What is the difficulty in adding all template parameters in the parameter list of the parent view?