[cgiapp] proposal for new cgiapp hook: loaded_html_tmpl

[Michael Graham]

Here's a new proposal for solving the multiple template parsing problem
when die_on_bad_params is enabled.  Add another callback to
CGI::Application:  

    loaded_html_tmpl

This gets called with the newly created template object before it gets
returned to the user.  CAP::AnyTemplate and CAP::TT would not call this
hook.

Plugins wishing to automatically pass variables to templates would do
the following:

  * hook the 'load_tmpl' callback
    - if html_tmpl_class isa 'HTML::Template' then return.  
    - Otherwise, add parameters to $tmpl_params

  * hook the 'loaded_html_template' callback
    - return unless html_tmpl_class isa 'HTML::Template' 
    - check $ht_params for die_on_bad_params (default to 1)
    - if die_on_bad_params is enabled, use HTML::Template's query method
      to determine whether or not it is safe to add the parameter.
    - if it is safe, add the parameter via $tmpl->param();

I don't know how many people use die_on_bad_params, so I don't
know how worth it it is to modify the core.

However, this hook would improve performance for users of
die_on_bad_params when using plugins that automatically add
template values, and it would greatly simplify the code required in
each of these plugins.


Michael


-- 
Michael Graham <magog at the-wire.com>