Forum OpenACS Development: Re: new templating model: ideas, questions

Collapse
Posted by Tom Jackson on

It seems quite bizarre that the XSL can have valid '$var's in their tags and html cannot. One thing I like the XMLish tag for, WRT the set proc is the possible usage of something like <tcl:set var />, which would be like [set var], instead of setting a variable, it would return the value of, in this case, 'var'.

I'm pretty sure I'm not going to rewrite HTML tags as part of a solution to this. That seems not helpful for designers or developers.

In the example given, I wonder how the selected attribute works, since it is just the text 'selected' inside the option tag?

I've verified this scanner/parser will work with UTF-8, for now except for '\0', which I am working on.

Collapse
Posted by Andrei Popov on

Tom,

As I said before -- whatever you see above is not real XSL. For one thing, when transforming an XML doc one does not need to handle situations of foreach {foo bar baz} $select nature, since you always look only at a foo or at a bar or at baz (as elements) and never at all of them together — you are following through the branch trees, pretty much one at a time.

My point was not in saying "Let's just use XSL/XSLT as templating basis" but rather "Look, templating language *can* be made valid XML and that without (much) sacrifice of readability"

Whether a '$var' or a 'var' should be used in the examples (and I think I was not very consistent in that usage) — this needs to be looked at and decided. You can pretty much have whatever you want in quotes, just as well as within a CDATA in XML. It would be Templating System's parser task to actualy decide upon what needs to be done with a particular '$var'. This could be made more Tcl-like (as in [set foo "bar"] as opposed to Perl's $foo="bar") or less.

Oh, and if we wanted to really use XSL, I think we could just use tDOM to do the transformation.

Collapse
Posted by Tom Jackson on

Well I've looked more into Dreamweaver and found that it is very easy to add new tag types. I think I can come up with a compromise that will allow easy usage in Dreamweaver and allow my compiler to easily identify valid code.

It turns out that in Dreamweaver, if you want to include code escapes inside attributes, you really need to use what they call an empty tag. For example, jsp/asp tags: <% %>, there is no ending tag.

So at the moment, I'm considering the following examples as equivalent:

[if $x]           [%if $x %]
[elseif {a==$b}]  [%elseif {a==$b} %]
[else]            [%else%]
[/if]             [%/if%]
[set a b/]        [%set a b /%] 
[set a/]          [%set a%] or [%= a /%] (ret value of a)
[foreach a $b]    [%foreach a $b %]
[/foreach]        [%/foreach%]
[resource text "header" ${title} /] ...

The templating language parser is helped by different ending tokens for tags like set and resource, thus the ending /] or /%] for those tags.

Collapse
Posted by Andrei Popov on
Wouldn't it make code a bit unreadable?  Also, why not then just using ADP as it was designed -- embeding code into your pages?  You'd get the <% %> pair for free then :))
Collapse
Posted by Tom Jackson on

Umm, it isn't adp! Only a few processing commands will be available, and command arguments and variables cannot contain embeded commands, and adp, requires AOLserver...First I have to satisfy the goals outlined above.