template::declare::tagset(3pm) [debian man page]
Template::Declare::TagSet(3pm) User Contributed Perl Documentation Template::Declare::TagSet(3pm) NAME
Template::Declare::TagSet - Base class for tag sets used by Template::Declare::Tags SYNOPSIS
package My::TagSet; use base 'Template::Declare::TagSet'; # returns an array ref for the tag names sub get_tag_list { [ qw( html body tr td table base meta link hr )] } # prevents potential naming conflicts: sub get_alternate_spelling { my ($self, $tag) = @_; return 'row' if $tag eq 'tr'; return 'cell' if $tag eq 'td'; } # Specifies whether "<tag></tag>" can be # combined to "<tag />": sub can_combine_empty_tags { my ($self, $tag) = @_; $tag =~ /^ (?: base | meta | link | hr ) $/x; } DESCRIPTION
Template::Declare::TagSet is the base class for declaring packages of Template::Delcare tags. If you need to create new tags for use in your templates, this is the base class for you! Review the source code of Template::Declare::TagSet::HTML for a useful example. METHODS
new( PARAMS ) my $tag_set = Template::Declare::TagSet->new({ package => 'Foo::Bar', namespace => undef, }); Constructor created by "Class::Accessor::Fast", accepting an optional hash reference of parameters. get_tag_list my $list = $tag_set->get_tag_list(); Returns an array ref for the tag names offered by a tag set. get_alternate_spelling( TAG ) $bool = $obj->get_alternate_spelling($tag); Returns true if a tag has an alternative spelling. Basically it provides a way to work around naming conflicts. For example, the "tr" tag in HTML conflicts with Perl's "tr" operator, and the "template" tag in XUL conflicts with the "template" sub exported by "Template::Declare::Tags". can_combine_empty_tags( TAG ) $bool = $obj->can_combine_empty_tags($tag); Specifies whether "<tag></tag>" can be combined into a single token, "<tag />". By default, all tags can be combined into a single token; override in a subclass to change this value where appropriate. For example, "Template::Declare::TagSet::HTML->can_combine_empty_tags('img')" returns true since "<img src="..." />" is always required for HTML pages. "Template::Declare::TagSet::HTML->can_combine_empty_tags('script')", on the other hand, returns false, since some browsers can't handle a single script token. ACCESSORS
This class has two read-only accessors: package my $package = $obj->package(); Retrieves the value of the "package" option set via the constructor. namespace my $namespace = $obj->namespace(); Retrieves the value of the "namespace" option set via the constructor. AUTHOR
Agent Zhang <agentzh@yahoo.cn>. SEE ALSO
Template::Declare::TagSet::HTML, Template::Declare::TagSet::XUL, Template::Declare::Tags, Template::Declare. perl v5.10.1 2010-12-08 Template::Declare::TagSet(3pm)
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Template::Declare::Tags(3pm) User Contributed Perl Documentation Template::Declare::Tags(3pm) NAME
Template::Declare::Tags - Build and install XML Tag subroutines for Template::Declare 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: <link /> <table> <tr> <td>Hello, world!</td> </tr> </table> <img src="cat.gif" /> <img src="dog.gif" /> 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: <groupbox> <caption label="Colors" /> <html:div> <html:p>howdy!</html:p> </html:div> <html:br></html:br> </groupbox> DESCRIPTION
"Template::Declare::Tags" 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 "use" statement: use Template::Declare::Tags qw/ HTML XUL /; By default, Template::Declare::Tags uses the tag set provided by Template::Declare::TagSet::HTML. So use Template::Declare::Tags; is equivalent to use Template::Declare::Tags 'HTML'; Currently Template::Declare bundles the following tag sets: Template::Declare::TagSet::HTML, Template::Declare::TagSet::XUL, Template::Declare::TagSet::RDF, and Template::Declare::TagSet::RDF::EM. You can specify your own tag set classes, as long as they subclass Template::Declare::TagSet and implement the corresponding methods (e.g. "get_tag_list"). If you implement a custom tag set module named "Template::Declare::TagSet::Foo", you can load it into a template module like so: use Template::Declare::Tags 'Foo'; If your tag set module is not under the Template::Declare::TagSet namespace, use the "from" option to load it. Fore example, if you created a tag set named "MyTag::Foo", 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 "html" 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: <groupbox> <caption label="Colors" /> <html:div> <html:p>howdy!</html:p> </html:div> <html:br></html:br> </groupbox> Behind the scenes, "Template::Declare::Tags" generates a Perl package named "html" and installs the HTML tag subroutines into that package. On the other hand, XUL tag subroutines are installed into the current package, namely, "MyApp::Templates" 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 "html" 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 "package" 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: <groupbox> <caption label="Colors" /> <htm:div> <htm:p>howdy!</htm:p> </htm:div> <htm:br></htm:br> </groupbox> METHODS AND SUBROUTINES
Declaring templates 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 "Template::Declare" object. Subsequent arguments will be all those passed to "show()". 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; "Template::Declare" will encode the template as a Perl subroutine and stash it where "show()" 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 "can"). private template TEMPLATENAME => sub { 'Implementation' }; private template select_list => sub { my $self = shift; select { option { $_ } for @_; } }; Declares that a template isn't available to be called directly from client code. The resulting template can instead only be called from the package in which it's created. Showing templates show [$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. "show" 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 "Template::Declare->show()", "show()" exported from Template::Declare::Tags or "Template::Declare::Tags::show()" directly to render a publicly visible template. Private templates may only be called from within the "Template::Declare" package. show_page show_page( main => { user => 'Bob' } ); Like "show()", but does not dispatch to private templates. It's used internally by "show()" when when that method is called from outside a template class. Attributes 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'; } ATTR is VALUE Attributes can also be specified by using "is", 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. 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 "attr" is: p { attr { id => 'greeting', class => 'foo' } 'Hello, World wide web' }; Displaying text and raw data outs STUFF p { outs 'Grettings & welcome pyoonie hyoomon.' } HTML-encodes its arguments and appends them to "Template::Declare"'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' } } outs_raw STUFF p { outs_raw "That's what <em>I'm</em> talking about!' } Appends its arguments to "Template::Declare"'s output buffer without HTML escaping. Installing tags and wrapping stuff 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 Template::Declare::TagSet. smart_tag_wrapper # create a tag that has access to the arguments set with L</with>. sub sample_smart_tag (&) { my $code = shift; smart_tag_wrapper { my %args = @_; # set using 'with' outs( 'keys: ' . join( ', ', sort keys %args) . " " ); $code->(); }; } # use it with ( foo => 'bar', baz => 'bundy' ), sample_smart_tag { outs( "Hello, World! " ); }; 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 "with". It passes those arguments in to the wrapped code in @_. 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 "with". create_wrapper WRAPPERNAME => sub { 'Implementation' }; create_wrapper basics => sub { my $code = shift; html { head { title { 'Welcome' } }; body { $code->() } } }; "create_wrapper" 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 "wrap" wrapper function is available for calling after it has been declared in a "BEGIN" 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: <html> <head> <title>Hello, Jesse!</title> </head> <body> <h1>Hello, Jesse, s'up?</h1> <div>This is the end, my friend</div> </body> </html> Helpers 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: <?xml version="1.0"?> <?xml-stylesheet href="chrome://global/skin/" type="text/css"?> current_template my $path = current_template(); Returns the absolute path of the current template current_base_path my $path = current_base_path(); Returns the absolute base path of the current template under "under" is a helper function providing semantic sugar for the "mix" method of Template::Declare. setting "setting" is a helper function providing semantic sugar for the "mix" method of Template::Declare. VARIABLES
@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. @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 "use Template::Decalre::Tags" statement. @Template::Declare::Tags::TagSubs is aliased to this variable for backward-compatibility. $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 <body> <pre> <script src="foo.js"></script> </pre> </body> Note that now the "script" tag has no indentation and we've got what we want. ;) $Template::Declare::Tags::SKIP_XML_ESCAPING Disables XML escape postprocessing entirely. Use at your own risk. SEE ALSO
Template::Declare::TagSet::HTML, Template::Declare::TagSet::XUL, Template::Declare. AUTHORS
Jesse Vincent <jesse@bestpractical.com> Agent Zhang <agentzh@yahoo.cn> COPYRIGHT
Copyright 2006-2009 Best Practical Solutions, LLC. perl v5.10.1 2011-04-15 Template::Declare::Tags(3pm)