How to include Template::Toolkit- Macros?

Question

This question is about the usage of macros from Template::Toolkit (Perl)

I`m failing to write macros and putting them into a separate file to use them within several other template files.

My macros are located in a separate template file named macros.tt:

----- file macros.tt ------
[% MACRO decorateStatus(status) BLOCK -%]
    [% ico = 'status_unknown' -%]
    [% IF status == "New" -%][% ico = 'status_waiting' -%]
    [% ELSIF status == "Working" -%][% ico = 'status_work' -%]
    [% ELSIF status == "Deleted" -%][% ico = 'status_deleted' -%]
    [% END -%]
    [% status %] <img src="[% c.uri_for('/images/ico/' _ ico _ '.png') %]" text="[% status %]">
[% END-%]

Now I’m trying to use this macro within another template – but this fails as the macro is not expanded:

----- file demo.tt -------
[% INCLUDE macros.tt %]
….
[% status = ‘New’ %]
<td>[% decorateStatus(status) %]</td>
….

Putting the macro directly in the file where I want to use it, everything works as expected.

What’s the “correct” way to include macros from a different file?

Answer 1

Using INCLUDE, all variable definitions (and a macro is really just a fancy variable) are localised to the included file. Which means the macros definitions aren't visible outside of the included file.

To make the macros visible in the calling file, you need PROCESS instead of INCLUDE. As the documentation says:

The PROCESS directive is similar to INCLUDE but does not perform any localisation of variables before processing the template. Any changes made to variables within the included template will be visible in the including template.

Answer 2

If you are using more than 1 template file with macros shared among them, try this:

Easier and cleaner than including [% PROCESS 'macros.tt' %] in every template is to make TT process your macros file before every call with PRE_PROCESS.

use Template;

my $tt = Template->new({
    INCLUDE_PATH => '/usr/local/templates',
    PRE_PROCESS  => 'macros.tt',
})