[Petal] Modifiers and variables

[Jean-Michel Hiver]

> I'm working on adding several new modifiers to Petal::Utils and have
> come across an interesting proposal which I wanted to float with the
> list.
> 
> When processing arguments passed to a modifier, there is not yet a
> standard way of reading these values (at least to my knowledge).

How do you mean? When you write a modifier, you have access to the raw 
string that comes after the modifier. What you do with that string is up 
to you.

Look at Petal::Hash::String and Petal::Hash for examples.


> Warren
> S. submitted a couple of modifiers which included a subroutine that he
> devised which fetches the arguments in the following way:
> 
>   1 - if the argument is a number (decimals are OK) or contains single
>   quotes, return the argument itself (i.e., plaintext)
>   2 - otherwise use the argument as the key to the hash and return that
>   value

Interesting, maybe this behavior could be implemented in an abstract 
modifier which could be subclassed at will.


> I like this as it makes it really easy to pass in plain text without
> having to use the string: modifier. However, I'm not sure whether this
> is considered TAL compliant. What are your thoughts? I've included the
> subroutine at the end.

Well, it's not TALES (TAL Expression Syntax) compliant. However in my 
view what's inside the TAL attributes doesn't really matter since it's 
pretty much application-dependant anyway.

Petal has never been TALES compliant since it lets you pass argument to 
methods, which in my knowledge is not supported by TALES.


Cheers,
Jean-Michel.