What is the mechanism behind view helpers?

I wonder what approach Rails uses to find the correct method of a view helper. I recognized while calling a view helper method in a partial that the view helper must not belong to the same view nor must it have a similar name, the method is always found. If mor开发者_StackOverflowe than one view helper has the same method, there is some logic behind to find the "nearest" helper and use this method. Is that mechanism somewhere documented (or blogged about in detail)?

My guess would be:

The view class automatically includes the helper modules in the order of increasing priority("near"ness). The "nearest" helper module is included last, and its methods override any previously defined methods with the same name.