如何在StringTemplate中的对象上调用C＃扩展方法？

Question

I'm trying to do an if...then in StringTemplate based on the number of items in a collection. I want to do this:

$if(length(myCollection) > 1)$

But, this is considered logic, and is therefore forbidden (StringTemplate doesn't recognize the > operator).

But, will StringTemplate reflect out an extension method?

My extension method looks like this:

public static bool IsMoreThanOne(this ICollection list)
{
    return list.Count > 1;
}

If my template looks like this:

$if(myCollection.MoreThanOne)$

That would find the method if it were a "first order" method (meaning on the "myCollection" object). But it's not -- it's an extension method, so it doesn't seem to be working.

Answer 1

For this particular logic you can use the following expression, which basically says "if we skip the first item, does the remaining collection contain any items?":

$if(rest(myCollection))$

In general, you can create an implementation of IModelAdaptor which supports accessing specific properties of your object. If your implementation extends ObjectModelAdaptor or MapModelAdaptor , you can fall back to return base.GetProperty(...) for any properties that you don't handle yourself.