Each actor type needs to evaluate attributes; only a few do. Strings
are handled with the "@foo()" notation.
Instead, after loading an XML file for loading as an actor,
precompile all XML attributes as Lua expressions.
The primary difference to code is:
- previously, Attr="string" would act as a string if it was being
read as one. Now, specify Attr='"string"'. Attr="@string" is
a shorthand. (note that @strings will not be parsed as Lua
strings, so can not use Lua escape characters)
- previously, Attr="@func()" would evaluate func(), and the value
of the attribute would be the return value of the function. This
was only supported for a few attributes. Now, say Attr="func()",
and this will work for all fields.
- Attributes of other types are unchanged, except that all attributes
may be Lua expressions, eg. Width="SCREEN_WIDTH".
- Attributes names ending with "Command" are special, like metrics.
Prefix "%" to disable this.
This brings XML handling in line with metric handling. (This is an intermediary
step; I have another idea that follows from this that should eliminate the annoying
"'foo'"/"@foo".)
For each actor, create a context table, with an __index link to the
parent's. This can be used to propagate information down complex
actor trees.
Code needs to be changed to do AddChild() calls before loading,
rather than after, so context links are available during loads.
This will be done as necessary.
Steve Checkoway