use 5.006; use warnings; use strict; #use Smart::Comments; #use Smart::Comments '####'; package Template::Declare::Tags; our $VERSION = '0.43'; use Template::Declare; use base 'Exporter'; use Carp qw(carp croak); use Symbol 'qualify_to_ref'; our $self; our @EXPORT = qw( template private current_template current_base_path show show_page attr with get_current_attr outs outs_raw xml_decl under setting smart_tag_wrapper create_wrapper $self ); our @TAG_SUB_LIST; our @TagSubs; *TagSubs = \@TAG_SUB_LIST; # For backward compatibility only our %ATTRIBUTES = (); our %ELEMENT_ID_CACHE = (); our $TAG_NEST_DEPTH = 0; our $TAG_INDENTATION = 1; our $EOL = "\n"; our @TEMPLATE_STACK = (); our $SKIP_XML_ESCAPING = 0; sub import { my $self = shift; my @set_modules; if (!@_) { push @_, 'HTML'; } ### @_ ### caller: caller() # XXX We can't reset @TAG_SUB_LIST here since # use statements always run at BEGIN time. # A better approach may be install such lists # directly into the caller's namespace... #undef @TAG_SUB_LIST; while (@_) { my $lang = shift; my $opts; if (ref $_[0] and ref $_[0] eq 'HASH') { $opts = shift; $opts->{package} ||= $opts->{namespace}; # XXX TODO: carp if the derived package already exists? } $opts->{package} ||= scalar(caller); my $module = $opts->{from} || "Template::Declare::TagSet::$lang"; ### Loading tag set: $module if (! $module->can('get_tag_list') ) { eval "use $module"; if ($@) { warn $@; croak "Failed to load tagset module $module"; } } ### TagSet options: $opts my $tagset = $module->new($opts); my $tag_list = $tagset->get_tag_list; Template::Declare::Tags::install_tag($_, $tagset) for @$tag_list; } __PACKAGE__->export_to_level(1, $self); } sub _install { my ($override, $package, $subname, $coderef) = @_; my $name = $package . '::' . $subname; my $slot = qualify_to_ref($name); return if !$override and *$slot{CODE}; no warnings 'redefine'; *$slot = $coderef; } =head1 NAME Template::Declare::Tags - Build and install XML Tag subroutines for Template::Declare =head1 SYNOPSIS package MyApp::Templates; use base 'Template::Declare'; use Template::Declare::Tags 'HTML'; template main => sub { link {} table { row { cell { "Hello, world!" } } } img { attr { src => 'cat.gif' } } img { src is 'dog.gif' } }; Produces:
Hello, world!
Using XUL templates with a namespace: package MyApp::Templates; use base 'Template::Declare'; use Template::Declare::Tags 'XUL', HTML => { namespace => 'html' }; template main => sub { groupbox { caption { attr { label => 'Colors' } } html::div { html::p { 'howdy!' } } html::br {} } }; Produces: howdy! =head1 DESCRIPTION C is used to generate templates and install subroutines for tag sets into the calling namespace. You can specify the tag sets to install by providing a list of tag modules in the C statement: use Template::Declare::Tags qw/ HTML XUL /; By default, Template::Declare::Tags uses the tag set provided by L. So use Template::Declare::Tags; is equivalent to use Template::Declare::Tags 'HTML'; Currently L bundles the following tag sets: L, L, L, and L. You can specify your own tag set classes, as long as they subclass L and implement the corresponding methods (e.g. C). If you implement a custom tag set module named C, you can load it into a template module like so: use Template::Declare::Tags 'Foo'; If your tag set module is not under the L namespace, use the C option to load it. Fore example, if you created a tag set named C, then you could load it like so: use Template::Declare::Tags Foo => { from => 'MyTag::Foo' }; XML namespaces are emulated by Perl packages. For example, to embed HTML tags within XUL using the C namespace: package MyApp::Templates; use base 'Template::Declare'; use Template::Declare::Tags 'XUL', HTML => { namespace => 'html' }; template main => sub { groupbox { caption { attr { label => 'Colors' } } html::div { html::p { 'howdy!' } } html::br {} } }; This will output: howdy! Behind the scenes, C generates a Perl package named C and installs the HTML tag subroutines into that package. On the other hand, XUL tag subroutines are installed into the current package, namely, C in the previous example. There may be cases when you want to specify a different Perl package for a particular XML namespace. For instance, if the C Perl package has already been used for other purposes in your application and you don't want to install subs there and mess things up, use the C option to install them elsewhere: package MyApp::Templates; use base 'Template::Declare'; use Template::Declare::Tags 'XUL', HTML => { namespace => 'htm', package => 'MyHtml' }; template main => sub { groupbox { caption { attr { label => 'Colors' } } MyHtml::div { MyHtml::p { 'howdy!' } } MyHtml::br {} } }; This code will generate something like the following: howdy! =head1 METHODS AND SUBROUTINES =head2 Declaring templates =head3 template TEMPLATENAME => sub { 'Implementation' }; template select_list => sub { my $self = shift; select { option { $_ } for @_; } }; Declares a template in the current package. The first argument to the template subroutine will always be a C object. Subsequent arguments will be all those passed to C. For example, to use the above example to output a select list of colors, you'd call it like so: Template::Declare->show('select_list', qw(red yellow green purple)); You can use any URL-legal characters in the template name; C will encode the template as a Perl subroutine and stash it where C can find it. (Did you know that you can have characters like ":" and "/" in your Perl subroutine names? The easy way to get at them is with C). =cut sub template ($$) { my $template_name = shift; my $coderef = shift; my $template_class = ( caller(0) )[0]; no warnings qw( uninitialized redefine ); # template "foo" ==> CallerPkg::_jifty_template_foo; # template "foo/bar" ==> CallerPkg::_jifty_template_foo/bar; my $codesub = sub { local $self = shift || $self || $template_class; unshift @_, $self, $coderef; goto $self->can('_dispatch_template'); }; if (wantarray) { # We're being called by something like private that doesn't want us to register ourselves return ( $template_class, $template_name, $codesub ); } else { # We've been called in a void context and should register this template Template::Declare::register_template( $template_class, $template_name, $codesub, ); } } =head3 private template TEMPLATENAME => sub { 'Implementation' }; private template select_list => sub { my $self = shift; select { option { $_ } for @_; } }; Declares that a template isn't available to be called directly from client code. The resulting template can instead only be called from the package in which it's created. =cut sub private (@) { my $class = shift; my $subname = shift; my $code = shift; Template::Declare::register_private_template( $class, $subname, $code ); } =head2 Showing templates =head3 show [$template_name or $template_coderef], args show( main => { user => 'Bob' } ); Displays templates. The first argument is the name of the template to be displayed. Any additional arguments will be passed directly to the template. C can either be called with a template name or a package/object and a template. (It's both functional and OO.) If called from within a Template::Declare subclass, then private templates are accessible and visible. If called from something that isn't a Template::Declare, only public templates will be visible. From the outside world, users can either call C<< Template::Declare->show() >>, C<< show() >> exported from Template::Declare::Tags or C directly to render a publicly visible template. Private templates may only be called from within the C package. =cut sub show { my $template = shift; # if we're inside a template, we should show private templates if ( caller->isa('Template::Declare') ) { _show_template( $template, 1, \@_ ); return Template::Declare->buffer->data; } else { show_page( $template, @_); } } =head3 show_page show_page( main => { user => 'Bob' } ); Like C, but does not dispatch to private templates. It's used internally by C when when that method is called from outside a template class. =cut sub show_page { my $template = shift; my $args = \@_; Template::Declare->buffer->push( private => defined wantarray, from => "T::D path $template", ); _show_template( $template, 0, $args ); %ELEMENT_ID_CACHE = (); return Template::Declare->buffer->pop; } =head2 Attributes =head3 attr HASH attr { src => 'logo.png' }; Specifies attributes for the element tag in which it appears. For example, to add a class and ID to an HTML paragraph: p { attr { class => 'greeting text', id => 'welcome', }; 'This is a welcoming paragraph'; } =cut sub attr (&;@) { my $code = shift; my @rv = $code->(); while ( my ( $field, $val ) = splice( @rv, 0, 2 ) ) { # only defined whle in a tag context append_attr( $field, $val ); } return @_; } =head3 ATTR is VALUE Attributes can also be specified by using C, as in p { class is 'greeting text'; id is 'welcome'; 'This is a welcoming paragraph'; } A few tricks work for 'is': http_equiv is 'foo'; # => http-equiv="foo" xml__lang is 'foo'; # => xml:lang="foo" So double underscore replaced with colon and single underscore with dash. =cut # 'is' is declared later, when needed, using 'local *is::AUTOLOAD = sub {};' =head3 with with ( id => 'greeting', class => 'foo' ), p { 'Hello, World wide web' }; An alternative way to specify attributes for a tag, just for variation. The standard way to do the same as this example using C is: p { attr { id => 'greeting', class => 'foo' } 'Hello, World wide web' }; =cut sub with (@) { %ATTRIBUTES = (); while ( my ( $key, $val ) = splice( @_, 0, 2 ) ) { no warnings 'uninitialized'; $ATTRIBUTES{$key} = $val; if ( lc($key) eq 'id' ) { if ( $ELEMENT_ID_CACHE{$val}++ ) { my $msg = "HTML appears to contain illegal duplicate element id: $val"; die $msg if Template::Declare->strict; warn $msg; } } } wantarray ? () : ''; } =head2 Displaying text and raw data =head3 outs STUFF p { outs 'Grettings & welcome pyoonie hyoomon.' } HTML-encodes its arguments and appends them to C's output buffer. This is similar to simply returning a string from a tag function call, but is occasionally useful when you need to output a mix of things, as in: p { outs 'hello'; em { 'world' } } =head3 outs_raw STUFF p { outs_raw "That's what I'm talking about!' } Appends its arguments to C's output buffer without HTML escaping. =cut sub outs { _outs( 0, @_ ); } sub outs_raw { _outs( 1, @_ ); } =head2 Installing tags and wrapping stuff =head3 install_tag TAGNAME, TAGSET install_tag video => 'Template::Declare::TagSet::HTML'; Sets up TAGNAME as a tag that can be used in user templates. TAGSET is an instance of a subclass for L. =cut sub install_tag { my $tag = $_[0]; # we should not do lc($tag) here :) my $name = $tag; my $tagset = $_[1]; my $alternative = $tagset->get_alternate_spelling($tag); if ( defined $alternative ) { _install( 0, # do not override scalar(caller), $tag, sub (&) { die "$tag {...} is invalid; use $alternative {...} instead.\n"; } ); ### Exporting place-holder sub: $name # XXX TODO: more checking here if ($name !~ /^(?:base|tr|time)$/) { push @EXPORT, $name; push @TAG_SUB_LIST, $name; } $name = $alternative or return; } # We don't need this since we directly install # subs into the target package. #push @EXPORT, $name; push @TAG_SUB_LIST, $name; no strict 'refs'; no warnings 'redefine'; #### Installing tag: $name # XXX TODO: use sub _install to insert subs into the caller's package so as to support XML packages my $code = sub (&;$) { local *__ANON__ = $tag; if ( defined wantarray and not wantarray ) { # Scalar context - return a coderef that represents ourselves. my @__ = @_; my $_self = $self; my $sub = sub { local $self = $_self; local *__ANON__ = $tag; _tag($tagset, $tag, @__); }; bless $sub, 'Template::Declare::Tag'; return $sub; } else { _tag($tagset, $tag, @_); } }; _install( 1, # do override the existing sub with the same name $tagset->package => $name => $code ); } =head3 smart_tag_wrapper # create a tag that has access to the arguments set with L. sub sample_smart_tag (&) { my $code = shift; smart_tag_wrapper { my %args = @_; # set using 'with' outs( 'keys: ' . join( ', ', sort keys %args) . "\n" ); $code->(); }; } # use it with ( foo => 'bar', baz => 'bundy' ), sample_smart_tag { outs( "Hello, World!\n" ); }; The output would be keys: baz, foo Hello, World! The smart tag wrapper allows you to create code that has access to the attribute arguments specified via C. It passes those arguments in to the wrapped code in C<@_>. It also takes care of putting the output in the right place and tidying up after itself. This might be useful to change the behavior of a template based on attributes passed to C. =cut sub smart_tag_wrapper (&) { my $coderef = shift; Template::Declare->buffer->append($EOL); Template::Declare->buffer->push( from => "T::D tag wrapper", private => 1 ); my %attr = %ATTRIBUTES; %ATTRIBUTES = (); # prevent leakage my $last = join '', map { ref($_) ? $_ : _postprocess($_) } $coderef->(%attr); my $content = Template::Declare->buffer->pop; $content .= "$last" if not length $content and length $last; Template::Declare->buffer->append( $content ); return ''; } =head3 create_wrapper WRAPPERNAME => sub { 'Implementation' }; create_wrapper basics => sub { my $code = shift; html { head { title { 'Welcome' } }; body { $code->() } } }; C declares a wrapper subroutine that can be called like a tag sub, but can optionally take arguments to be passed to the wrapper sub. For example, if you wanted to wrap all of the output of a template in the usual HTML headers and footers, you can do something like this: package MyApp::Templates; use Template::Declare::Tags; use base 'Template::Declare'; BEGIN { create_wrapper wrap => sub { my $code = shift; my %params = @_; html { head { title { outs "Hello, $params{user}!"} }; body { $code->(); div { outs 'This is the end, my friend' }; }; } }; } template inner => sub { wrap { h1 { outs "Hello, Jesse, s'up?" }; } user => 'Jesse'; }; Note how the C wrapper function is available for calling after it has been declared in a C block. Also note how you can pass arguments to the function after the closing brace (you don't need a comma there!). The output from the "inner" template will look something like this: Hello, Jesse!

Hello, Jesse, s'up?

This is the end, my friend
=cut sub create_wrapper ($$) { my $wrapper_name = shift; my $coderef = shift; my $template_class = caller; # Shove the code ref into the calling class. no strict 'refs'; *{"$template_class\::$wrapper_name"} = sub (&;@) { goto $coderef }; } =head2 Helpers =head3 xml_decl HASH xml_decl { 'xml', version => '1.0' }; Emits an XML declaration. For example: xml_decl { 'xml', version => '1.0' }; xml_decl { 'xml-stylesheet', href => "chrome://global/skin/", type => "text/css" }; Produces: =cut sub xml_decl (&;$) { my $code = shift; my @rv = $code->(); my $name = shift @rv; outs_raw("$EOL"); return @_; } =head3 current_template my $path = current_template(); Returns the absolute path of the current template =cut sub current_template { return $TEMPLATE_STACK[-1] || ''; } =head3 current_base_path my $path = current_base_path(); Returns the absolute base path of the current template =cut sub current_base_path { # Rip it apart my @parts = split('/', current_template()); # Remove the last element pop @parts; # Put it back together again my $path = join('/', @parts); # And serve return $path; } =head3 under C is a helper function providing semantic sugar for the C method of L. =cut sub under ($) { return shift } =head3 setting C is a helper function providing semantic sugar for the C method of L. =cut sub setting ($) { return shift } =begin comment =head2 get_current_attr Deprecated. =end comment =cut sub get_current_attr ($) { $ATTRIBUTES{ $_[0] }; } sub _tag { my $tagset = shift; my $tag = shift; my $code = shift; my $more_code = shift; $tag = $tagset->namespace . ":$tag" if defined $tagset->namespace; Template::Declare->buffer->append( $EOL . ( " " x $TAG_NEST_DEPTH ) . "<$tag" . join( '', map { qq{ $_="} . ( $ATTRIBUTES{$_} || '' ) . qq{"} } sort keys %ATTRIBUTES ) ); my $attrs = ""; my $last; { no warnings qw( uninitialized redefine once ); local *is::AUTOLOAD = sub { shift; my $field = our $AUTOLOAD; $field =~ s/.*:://; $field =~ s/__/:/g; # xml__lang is 'foo' ====> xml:lang="foo" $field =~ s/_/-/g; # http_equiv is 'bar' ====> http-equiv="bar" # Squash empty values, but not '0' values my $val = join ' ', grep { defined $_ && $_ ne '' } @_; append_attr( $field, $val ); }; local *append_attr = sub { my $field = shift; my $val = shift; $attrs .= ' ' . $field . q{="} . _postprocess($val, 1) . q{"}; wantarray ? () : ''; }; local $TAG_NEST_DEPTH = $TAG_NEST_DEPTH + $TAG_INDENTATION; %ATTRIBUTES = (); Template::Declare->buffer->push( private => 1, from => "T::D tag $tag" ); $last = join '', map { ref($_) && $_->isa('Template::Declare::Tag') ? $_ : _postprocess($_) } $code->(); } my $content = Template::Declare->buffer->pop; $content .= "$last" if not length $content and length $last; Template::Declare->buffer->append($attrs) if length $attrs; if (length $content) { Template::Declare->buffer->append(">$content"); Template::Declare->buffer->append( $EOL . ( " " x $TAG_NEST_DEPTH )) if $content =~ /\buffer->append(""); } elsif ( $tagset->can_combine_empty_tags($tag) ) { Template::Declare->buffer->append(" />"); } else { # Otherwise we supply a closing tag. Template::Declare->buffer->append(">"); } return ( ref($more_code) && $more_code->isa('CODE') ) ? $more_code->() : ''; } sub _resolve_template_path { my $template = shift; my @parts; if ( substr($template, 0, 1) ne '/' ) { # relative @parts = split '/', current_template(); # Get rid of the parent's template name pop @parts; } foreach ( split '/', $template ) { if ( $_ eq '..' ) { pop @parts; } # Get rid of "." and empty entries by the way elsif ( $_ ne '.' && $_ ne '' ) { push @parts, $_; } } return join '/', @parts; } sub _show_template { my $template = shift; my $inside_template = shift; my $args = shift; $template = _resolve_template_path($template); local @TEMPLATE_STACK = (@TEMPLATE_STACK, $template); my $callable = ( ref($template) && $template->isa('Template::Declare::Tag') ) ? $template : Template::Declare->resolve_template( $template, $inside_template ); # If the template was not found let the user know. unless ($callable) { my $msg = "The template '$template' could not be found"; $msg .= " (it might be private)" if !$inside_template; croak $msg if Template::Declare->strict; carp $msg; return ''; } if (my $instrumentation = Template::Declare->around_template) { $instrumentation->( sub { &$callable($self, @$args) }, $template, $args, $callable, ); } else { &$callable($self, @$args); } return; } sub _outs { my $raw = shift; my @phrases = (@_); Template::Declare->buffer->push( private => (defined wantarray and not wantarray), from => "T::D outs" ); foreach my $item ( grep {defined} @phrases ) { my $returned = ref($item) eq 'CODE' ? $item->() : $raw ? $item : _postprocess($item); Template::Declare->buffer->append( $returned ); } return Template::Declare->buffer->pop; } sub _postprocess { my $val = shift; my $skip_postprocess = shift; return $val unless defined $val; # stringify in case $val is object with overloaded "" $val = "$val"; if ( ! $SKIP_XML_ESCAPING ) { no warnings 'uninitialized'; $val =~ s/&/&/g; $val =~ s//>/g; $val =~ s/\(/(/g; $val =~ s/\)/)/g; $val =~ s/"/"/g; $val =~ s/'/'/g; } $val = Template::Declare->postprocessor->($val) unless $skip_postprocess; return $val; } =begin comment =head2 append_attr C is a helper function providing an interface for setting attributes from within tags. But it's better to use C or C to set your attributes. Nohting to see here, really. Move along. =end comment =cut sub append_attr { die "Subroutine attr failed: $_[0] => '$_[1]'\n\t". "(Perhaps you're using an unknown tag in the outer container?)"; } =head1 VARIABLES =over 4 =item C<@Template::Declare::Tags::EXPORT> Holds the names of the static subroutines exported by this class. Tag subroutines generated by tag sets, however, are not included here. =item C<@Template::Declare::Tags::TAG_SUB_LIST> Contains the names of the tag subroutines generated from a tag set. Note that this array won't get cleared automatically before another C<< use Template::Decalre::Tags >> statement. C<@Template::Declare::Tags::TagSubs> is aliased to this variable for backward-compatibility. =item C<$Template::Declare::Tags::TAG_NEST_DEPTH> Controls the indentation of the XML tags in the final outputs. For example, you can temporarily disable a tag's indentation by the following lines of code: body { pre { local $Template::Declare::Tags::TAG_NEST_DEPTH = 0; script { attr { src => 'foo.js' } } } } It generates
 
  
Note that now the C