NAME

SYNOPSIS

    BeerDB->config->view("Maypole::View::TT"); # The default anyway

    # Set some Template Toolkit options
    BeerDB->config->view_options( {
        TRIM        => 1,
        COMPILE_DIR => '/var/tmp/mysite/templates',
    } );

    .....

    [% PROCESS macros %]

    [% pager %]

    [% link %]

    [% maybe_link_view %]

DESCRIPTION

The underlying Template toolkit object is configured through "$r->config->view_options". See Template for available options.

template

Processes the template and sets the output. See Maypole::View::Base

report_error

Reports the details of an error, current state and parameters

TEMPLATE TOOLKIT INTRODUCTION

A simple example would be :

TT uses '[%' and '%]' (by default) to delimit directives within a template, and the simple directives above just display the value of variable named within those delimiters -- [% title %] will be replaced inline with the value of the 'title' variable passed in the 'stash' to the template when it is processed.

You can access nested data through the dot ('.') operator, which will dereference array or hash elements, but can also be used to call methods on objects, i.e. '[% name.salutation("Dear %s,") %]'. The other main operator is underscore ('_'), which will concatonate strings or variables.

The value returned by a directive replaces the directive inline when the template is processes, you can also SET a value which will not return anything, or CALL a method or operation which will also not return anything.

You can specify expressions using the logical (and, or, not, ?:) and mathematic operators (+ - * / % mod div).

Results of TT commands are interpolated in the place of the template tags, unless using SET or CALL, i.e. [% SET foo = 1 %], [% GET foo.bar('quz'); %]

TT allows you to include or re-use templates through it's INCLUDE, PROCESS and INSERT directives, which are fairly self explainatory. You can also re-use parts of template with the BLOCK or MACRO directives.

Conditional and Looping constructs are simple and powerful, and TT provides an inbuilt iterator and helper functions and classes that make life sweet.

Conditional directives are IF, UNLESS, ELSIF, ELSE and behave as they would in perl :

Looping directives are FOREACH, LAST and BREAK.

FOREACH loops through a HASH or ARRAY processing the enclosed block for each element.

Looping through an array

 [% FOREACH i = items %]
 [% i %]
 [% END %]

Looping through a hash

 [% FOREACH u IN users %]
 * [% u.key %] : [% u.value %]
 [% END %]

Looping through an array of hashes

 [% FOREACH user IN userlist %]
 * [% user.id %] [% user.name %]
 [% END %]

The LAST and BREAK directive can be used to exit the loop.

The FOREACH directive is implemented using the Template::Iterator module. A reference to the iterator object for a FOREACH directive is implicitly available in the 'loop' variable. The loop iterator object provides a selection of methods including size(), max(), first(), last(), count(), etc

  [% FOREACH item IN [ 'foo', 'bar', 'baz' ] -%]
    [%- "<ul>\n" IF loop.first %]
      <li>[% loop.count %]/[% loop.size %]: [% item %]
    [%- "</ul>\n" IF loop.last %]
  [% END %]

See Template::Iterator for further details on looping and the Iterator.

You might notice the minus ('-') operator in the example above, it is used to remove a newline before or after a directive so that you can layout the Template logic as above but the resulting output will look exactly how you require it.

You will also frequently see comments and multi-line directives, # at the start of a directive marks it as a comment, i.e. '[%# this is a comment %]'. A multiline directive looks like :

 [% do.this;
    do.that;
    do.the_other %]

You can see that lines are terminated with a semi-colon (';') unless the delimter ('%]') closes the directive.

For full details of the Template Toolkit see Template::Manual and Template::Manual::Directives, you can also check the website, mailing list or the Template Toolkit book published by O Reilly.

TEMPLATE PLUGINS, FILTERS AND MACROS

TT Plugins provide additional functionality within Templates, from accessing CGI and databases directly, handling paging or simple integration with Class::DBI (for those rare occasions where you don't actually need Maypole). See Template::Manual::Plugins.

One plugin that is indispensible when using Maypole and the Template View is "Template::Plugin::Class" -- This allows you to import and use any class installed within a template. For example :

Would do the equivilent of 'use Foo; Foo->bar;' in perl. See Template::Plugin::Class for details.

TT Filters process strings or blocks within a template, allowing you to truncate, format, escape or encode trivially. A useful selection is included with Template Toolkit and they can also be found on CPAN or can be written easily. See Template::Manual::Filters.

TT provides stderr and stdout filters, which allow you to write handy macros like this one to output debug information to your web server log, etc :

TT Macros allow you to reuse small blocks of content, directives, etc. The MACRO directive allows you to define a directive or directive block which is then evaluated each time the macro is called. Macros can be passed named parameters when called.

Once a MACRO is defined within a template or 'include'd template it can be used as if it were a native TT directive. Maypole provides a selection of powerful and useful macros in the templates/ directory of the package and these are used in the beerdb and default templates. See the MACRO section of the Template::Manual::Directives documentation.

ACCESSING MAYPOLE VALUES

MAYPOLE MACROS AND FILTERS

AUTHOR