[stringtemplate-interest] Top-Down automatic attributeaggregation?

[Kunle Odutola]

> Hi!

G'day Ulf,



> An Attribute can be:

> An ArrayList containing either more Hashtables(deeper nesting)

> or a single String



ST# treats attributes whose values are of types that implement IList
specially. They are considered to be multi-valued attributes.



> WHAT WORKS:

>

> Calling strictly hirarchical templates does work with this

> structure.

>

> With a datastructure of Foo.Bar

> .FooBar

>

> TemplateA(Foo) ::= << $Foo:TemplateB$ >>

> TemplateB() ::= << $it.Bar$ ; $it.FooBar$ >>

>

> evaluates correctly.

>

> PROBLEM:

>

> I now can NOT access the deeper nestings of the structure.

> With above structure the following access

>

> TemplateA(Foo) ::= << $Foo.FooBar$ >>

>

> gives me a

> "Class System.Collections.ArrayList has no such attribute:

> FooBar in template context [TemplateA]"

>

> When calling subtemplates with parameters ST seems to

> 'ignore' the additional ArrayList-layer (resolving it as expected)

> but when accessing Foo.FooBar the ArrayList gets in the way.

> A Call to Foo.attributeList.FooBar also fails

> attributeList is my (for testing public) member which holds

> the ArrayList. (it involves wrapping ArrayList and giving it

> an accessor which (called with the string that designates

> the AL in the parent Hashtable) returns a reference to

> itself (the AL).



I might be missing something here but, ArrayList instances don't have a
FooBar member.



> So I have to ask: Has anyone any experience with this

> problem? Or do you Terence or Kunle have an idea to how a

> suitable data structure has to look?



No specials requirements beyond keeping in mind that ILists (e.g. arrays,
arraylists etc) are treated specially. If you do use a list, remember that
you won't be able to access members by index. They are considered to be
multi-valued attributes and you can iterate over the contents as one would
expect.



> I don't have enough understanding of how ST gets its

> attributes from a given datastructure to figure out something better.

>

> I fear to ask how this would work out referencing PARENT

> attributes from sub-templates.



What are parent attributes?



Kunle