=head1 Templates

Each template is split into two sections. A block of headers and a body. These
sections are separated by a blank line.

Templates are processed by the L<Text::Template> module. This module
allows you to embed arbitrary Perl code into your templates. Text wrapped
in curly braces, C<{...}> is interpreted as Perl. See L<Text::Template>
for more information.

=head2 Headers

Your template may specify arbitrary email headers. Each header is a name, a
colon, then a value. So, for example, to specify a subject, you can use:

    Subject: Thanks for your bug report.

=head3 Special Headers

=over

=item Content-Type: text/html

The special header "Content-Type: text/html" tells RT that the template should
be parsed as HTML. RT will automatically make the outgoing message multipart.
That way, recipients who can read only plaintext email will receive something
readable, while users with clients which can display HTML will receive the full
experience. Please be aware that HTML support in mail clients varies greatly,
much more so than different web browsers.

We welcome contributions of HTML-ization of builtin templates.

=back

=head2 Template Types

Templates have a Type which dictates which level of code execution is
allowed.

Templates of type C<Perl> are evaluated using L<Text::Template>
which allows arbitrary code execution. Only users which have the global
C<ExecuteCode> privilege may write templates of type C<Perl>. Prior to
RT 4.0, this was the only type of Template available.

Templates of type C<Simple> permit only simple variable interpolation.
No special privilege beyond C<ModifyTemplate> is needed to write C<Simple>
templates.

For both types of templates, text between curly braces C<{ ... }> is
interpolated. For C<Perl> templates, this text can be any code (see
L<Text::Template/Details>). For C<Simple> templates, only simple variables
are permitted; for example C<{ $TicketSubject }>.

=head2 Variables

=head3 Perl templates

The variables that your templates may use include:

=over 4

=item C<$Transaction>

The transaction object.

=item C<$rtname>

The value of the "rtname" config variable.

=item C<$Ticket>

The ticket object. This is only set during a ticket transaction.

=item C<$Requestor>

This is not an object, but the name of the first requestor on the ticket.
If this is not what you need, inspect C<< $Ticket->Requestors >>.

=item C<loc("text")>

A localization function. See L<Locale::Maketext>.

=back

=head3 Selected Simple template variables

Since method calls are not allowed in simple templates, many common
method results have been placed into scalar variables for the template's
use.  Among them:

=over 4

=item $TicketId

=item $TicketSubject

=item $TicketStatus

=item $TicketQueueName

=item $TicketOwnerName

=item $TicketOwnerEmailAddress

=item $TicketCF(Name)

For example, C<$TicketCFDepartment>.

=item $TransactionType

=item $TransactionField

=item $TransactionOldValue

=item $TransactionNewValue

=item $TransactionData

=item $TransactionContent

=item $TransactionDescription

=item $TransactionBriefDescription

=item $TransactionCF(Name)

For example, C<$TransactionCFLocation>.

=back

=cut