There are actually some formats that, while not requiring it per se ... it just really helps to know about everything ahead of time. I know it helps me in PDF::Template to have all the data ahead of time. This is because it's a paginated format, which means I need to calculate page numbers and the like. Knowing how much more data there is allows me to calculate the final page number, so you can do things like Page 1 / 45 and have it look right. (I'm sure there's other ways to do it, but that's what I've got so far.)
As for HTML::Template, you might want to look at HTML::Template::Expr if you want expanded functionality. Or, just take the plunge and go to Template Toolkit.
Speaking as a template author, callbacks can be ... problematic. They're not easy to write an API around. Just a few problems I have with them:
- Are all CODE references to be considered callbacks?
- Are callbacks allowed in any type of variable? Scalars are easy, but what about loop variables that need to return a hashref for the current iteration?
- What happens if a callback dies? Should I call the callback within an eval block? What do I do with $@?
- Should I allow for parameters to be passed to the callback? What is the interface within the template for that?
- Do I allow for eval within the template? How does that play with mod_perl and other persistent environments? What about safety concerns - templates are sometimes under the control of another group from the Perl developers ...
Not so simple ...
Being right, does not endow the right to be rude; politeness costs nothing. Being unknowing, is not the same as being stupid. Expressing a contrary opinion, whether to the individual or the group, is more often a sign of deeper thought than of cantankerous belligerence. Do not mistake your goals as the only goals; your opinion as the only opinion; your confidence as correctness. Saying you know better is not the same as explaining you know better.
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|