Cart Example

package Template::Flute; use strict; use warnings; use Template::Flute::Utils; use Template::Flute::Specification::XML; use Template::Flute::HTML; =head1 NAME Template::Flute - Modern HTML Engine =head1 VERSION Version 0.0001 =cut our $VERSION = '0.0001'; =head1 SYNOPSIS use Template::Flute; my ($cart, $flute, %values); $cart = [{...},{...}]; $values{cost} = ... $flute = new Template::Flute(specification_file => 'cart.xml', template_file => 'cart.html', iterators => {cart => $cart}, values => \%values, ); print $flute->process(); =head1 DESCRIPTION Template::Flute enables you to completely separate web design and programming tasks for dynamic web applications. Templates are plain HTML files without inline code or mini language, thus making it easy to maintain them for web designers and to preview them with a browser. The CSS selectors in the template are tied to your data structures or objects by a specification, which relieves the programmer from changing his code for mere changes of class names. =head2 Workflow The easiest way to use Template::Flute is to pass all necessary parameters to the constructor and call the process method to generate the HTML. You can also break it down in separate steps: =over 4 =item 1. Parse specification Parse specification based on your specification format (e.g with L or L.). $xml_spec = new Template::Flute::Specification::XML; $spec = $xml_spec->parse(q{ }); =item 2. Parse template Parse template with L object. $template = new Template::Flute::HTML; $template->parse(q{ Cart Example

Name	Quantity	Price
Sample Book		$1
		Total
		$10

}, $spec); =item 3. Produce HTML output $zoom = new Template::Zoom(template => $template, iterators => {cart => $cart}, values => {cost => '84.94'}); $zoom->process(); =back =head1 CONSTRUCTOR =head2 new Create a Template::Flute object with the following parameters: =over 4 =item specification_file Specification file name. =item specification_parser Select specification parser. This can be either the full class name like L or the last part for classes residing in the Template::Flute::Specification namespace. =item template_file HTML template file. =item database L object. =item filters Hash reference of filter functions. =item i18n L object. =item values Hash reference of values to be used by the process method. =back =cut # Constructor sub new { my ($class, $self); $class = shift; $self = {@_}; bless $self; } sub _bootstrap { my ($self) = @_; my ($parser_name, $parser_spec, $spec_file, $spec, $template_file, $template_object); unless ($self->{specification}) { unless ($self->{specification_file}) { # try to derive specification file name from template file name $self->{specification_file} = Template::Flute::Utils::derive_filename($self->{template_file}, '.xml'); unless (-f $self->{specification_file}) { die "Missing Template::Flute specification for template $self->{template_file}\n"; } } if ($parser_name = $self->{specification_parser}) { # load parser class my $class; if ($parser_name =~ /::/) { $class = $parser_name; } else { $class = "Template::Flute::Specification::$parser_name"; } eval "require $class"; if ($@) { die "Failed to load class $class as specification parser: $@\n"; } eval { $parser_spec = $class->new(); }; if ($@) { die "Failed to instantiate class $class as specification parser: $@\n"; } } else { $parser_spec = new Template::Flute::Specification::XML; } if ($spec_file = $self->{specification_file}) { unless ($self->{specification} = $parser_spec->parse_file($spec_file)) { die "$0: error parsing $spec_file: " . $parser_spec->error() . "\n"; } } else { die "$0: Missing Template::Flute specification, template: $self->{template_file}.\n"; } } my ($name, $iter); while (($name, $iter) = each %{$self->{iterators}}) { $self->{specification}->set_iterator($name, $iter); } if ($template_file = $self->{template_file}) { $template_object = new Template::Flute::HTML; $template_object->parse_file($template_file, $self->{specification}); $self->{template} = $template_object; } else { die "$0: Missing Template::Flute template.\n"; } } =head1 METHODS =head2 process [HASHREF] Processes HTML template and returns HTML output. =cut sub process { my ($self, $params) = @_; my ($dbobj, $iter, $sth, $row, $lel, %paste_pos, $query); unless ($self->{template}) { $self->_bootstrap(); } if ($self->{i18n}) { # translate static text first $self->{template}->translate($self->{i18n}); } # replace simple values $self->_replace_values(); for my $container ($self->{template}->containers()) { if (exists $self->{values}) { $container->set_values($self->{values}); } unless ($container->visible()) { $container->elt()->cut(); } } # determine database queries for my $list ($self->{template}->lists()) { # check for (required) input unless ($list->input($params)) { die "Input missing for " . $list->name . "\n"; } unless ($iter = $list->iterator()) { if ($self->{database}) { if ($query = $list->query()) { $iter = $self->{database}->build($query); $iter->run(); } else { die "$0: List " . $list->name . " without iterator and database query.\n"; } } else { die "$0: List " . $list->name . " without iterator and database object.\n"; } } # process template $lel = $list->elt(); if ($lel->is_last_child()) { %paste_pos = (last_child => $lel->parent()); } elsif ($lel->next_sibling()) { %paste_pos = (before => $lel->next_sibling()); } else { # list is root element in the template %paste_pos = (last_child => $self->{template}->{xml}); } $lel->cut(); my ($row,); my $row_pos = 0; while ($row = $iter->next()) { if ($row = $list->filter($self, $row)) { $self->_replace_record($list, 'list', $lel, \%paste_pos, $row, $row_pos); $row_pos++; $list->increment(); } } } for my $form ($self->{template}->forms()) { $lel = $form->elt(); if ($lel->is_last_child()) { %paste_pos = (last_child => $lel->parent()); } elsif ($lel->next_sibling()) { %paste_pos = (before => $lel->next_sibling()); } else { # list is root element in the template %paste_pos = (last_child => $self->{template}->{xml}); } $lel->cut(); if (keys(%{$form->inputs()}) && $form->input()) { $iter = $dbobj->build($form->query()); $self->_replace_record($form, 'form', $lel, \%paste_pos, $iter->next()); } else { $self->_replace_record($form, 'form', $lel, \%paste_pos, {}); } } return $self->{template}->{xml}->sprint; } sub _replace_within_elts { my ($self, $param, $rep_str) = @_; my ($name, $zref); for my $elt (@{$param->{elts}}) { $name = $param->{name}; $zref = $elt->{"flute_$name"}; if ($zref->{rep_sub}) { # call subroutine to handle this element $zref->{rep_sub}->($elt, $rep_str); } elsif ($zref->{rep_att}) { # replace attribute instead of embedded text (e.g. for ) if (exists $param->{op} && $param->{op} eq 'append') { $elt->set_att($zref->{rep_att}, $zref->{rep_att_orig} . $rep_str); } elsif (exists $param->{op} && $param->{op} eq 'toggle') { if ($rep_str) { $elt->set_att($zref->{rep_att}, $rep_str); } else { $elt->del_att($zref->{rep_att}); } } else { $elt->set_att($zref->{rep_att}, $rep_str); } } elsif ($zref->{rep_elt}) { # use provided text element for replacement $zref->{rep_elt}->set_text($rep_str); } else { $elt->set_text($rep_str); } } } sub _replace_record { my ($self, $container, $type, $lel, $paste_pos, $record, $row_pos) = @_; my ($param, $key, $filter, $rep_str, $att_name, $att_spec, $att_tag_name, $att_tag_spec, %att_tags, $att_val, $class_alt); # now fill in params for $param (@{$container->params}) { $key = $param->{name}; $rep_str = $record->{$param->{field} || $key}; if ($param->{increment}) { $rep_str = $param->{increment}->value(); } if ($param->{subref}) { $rep_str = $param->{subref}->($record); } if ($param->{filter}) { $rep_str = $self->filter($param->{filter}, $rep_str); } $self->_replace_within_elts($param, $rep_str); } # now add to the template my $subtree = $lel->copy(); # alternate classes? if ($type eq 'list' && ($class_alt = $container->static_class($row_pos))) { $subtree->set_att('class', $class_alt); } $subtree->paste(%$paste_pos); } =head2 filter FILTER VALUE Runs the filter named FILTER on VALUE and returns the result. =cut sub filter { my ($self, $filter, $value) = @_; my ($rep_str); if (exists $self->{filters}->{$filter}) { $filter = $self->{filters}->{$filter}; $rep_str = $filter->($value); } else { die "Missing filter $filter\n"; } return $rep_str; } =head2 value NAME Returns the value for NAME. =cut sub value { my ($self, $value) = @_; my ($raw_value, $rep_str); if ($self->{scopes}) { if (exists $value->{scope}) { $raw_value = $self->{values}->{$value->{scope}}->{$value->{name}}; } else { $raw_value = $self->{values}->{$value->{name}}; } } else { $raw_value = $self->{values}->{$value->{name}}; } if ($value->{filter}) { $rep_str = $self->filter($value->{filter}, $raw_value); } else { $rep_str = $raw_value; } if (wantarray) { return ($raw_value, $rep_str); } return $rep_str; } sub _replace_values { my ($self) = @_; my ($value, $rep_str, @elts); for my $value ($self->{template}->values()) { @elts = @{$value->{elts}}; if (exists $value->{op} && $value->{op} eq 'toggle') { my $raw; ($raw, $rep_str) = $self->value($value); if (exists $value->{args} && $value->{args} eq 'static') { if ($rep_str) { # preserve static text next; } } unless ($raw) { # remove corresponding HTML elements from tree for my $elt (@elts) { $elt->cut(); } next; } } else { $rep_str = $self->value($value); } $self->_replace_within_elts($value, $rep_str); } } =head2 set_values HASHREF Sets hash reference of values to be used by the process method. Same as passing the hash reference as values argument to the constructor. =cut sub set_values { my ($self, $values) = @_; $self->{values} = $values; } =head2 template Returns HTML template object. =cut sub template { my $self = shift; return $self->{template}; } =head1 SPECIFICATION The specification ties the elements in the HTML template to the data (variables, lists, forms) which is added to the template. The default format for the specification is XML implemented by the L module. You can use the Config::Scoped format implemented by L module or write your own specification parser class. Possible elements in the specification are: =over 4 =item container This container is only shown in the output if the value billing_address is set: =item list =item param =item value =item input =item filter =item sort =item i18n =back =head1 ITERATORS Template::Flute uses iterators to retrieve list elements and insert them into the document tree. This abstraction relieves us from worrying about where the data actually comes from. We basically just need an array of hash references and an iterator class with a next and a count method. For your convenience you can create an iterator from L class very easily. =head1 LIST L =head1 FORMS L =head1 AUTHOR Stefan Hornburg (Racke), =head1 BUGS Please report any bugs or feature requests to C, or through the web interface at L. =head1 SUPPORT You can find documentation for this module with the perldoc command. perldoc Template::Flute You can also look for information at: =over 4 =item * RT: CPAN's request tracker L =item * AnnoCPAN: Annotated CPAN documentation L =item * CPAN Ratings L =item * Search CPAN L =back =head1 HISTORY Template::Flute was initially named Template::Zoom. I renamed the module because of a request from Matt S. Trout, author of the L module. =head1 LICENSE AND COPYRIGHT Copyright 2010-2011 Stefan Hornburg (Racke) . This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License. See http://dev.perl.org/licenses/ for more information. =cut 1;