Pages - Sub-category options based on main category selection

[alexm]

Well it's a lovely Saturday afternoon in blighty.

So I'm just wondering guys, I'm building a page which will be an add property page for estate agents.

Now I am using input field type Pages to create a dropdown list of property types as pages.

Then under these property types i would like subtypes.

So it may look like:

Houses -> Detached

             -> Semi-Detached

Another -> Another sub type

You get the idea

Now... 

I wanted to have it set up so when creating the page You select the Property type from the dropdown then Once you have chosen one the subcategory dropdown shows listing the subcategories of that category. 

I noticed when setting up the sub category's "Selectable pages" that custom PHP code is not compatible with page list selector so I'm looking for some advice on what would be the best way of going about achieving this?

I'm sorry if it has been asked before, I can't find the same question in the forum.

Thanks

[WillyC]

in 2.4 u do

https://processwire.com/talk/topic/4323-field-dependencies/?p=48910

[alexm]

Thanks WillyC as usual!