NAME
Catalyst::View::ByCode - Templating using pure Perl code
SYNOPSIS
# 1) use the helper to create your View
myapp_create.pl view ByCode ByCode
# 2) inside your Controllers do business as usual:
sub index :Path :Args(0) {
my ($self, $c) = @_;
# unless defined as default_view in your config, specify:
$c->stash->{current_view} = 'ByCode';
$c->stash->{title} = 'Hello ByCode';
# if omitted, would default to
# controller_namespace / action_namespace .pl
$c->stash->{template} = 'hello.pl';
}
# 3) create a simple template eg 'root/bycode/hello.pl
# REMARK:
# use 'c' instead of '$c'
# prefer 'stash->{...}' to 'c->stash->{...}'
template {
html {
head {
title { stash->{title} };
load Js => 'site.js';
load Css => 'site.css';
};
body {
div header.noprint {
ul.topnav {
li {'home'};
li {'surprise'};
};
};
div content {
h1 { stash->{title} };
div { 'hello.pl is running!' };
img(src => '/static/images/catalyst_logo.png');
};
};
};
};
# 274 characters without white space
# 4) expect to get this HTML generated:
<html>
<head>
<title>Hello ByCode!</title>
<script src="http://localhost:3000/js/site.js" type="text/javascript">
</script>
<link rel="stylesheet" href="http://localhost:3000/css/site.css" type="text/css" />
</head>
<body>
<div id="header" style="noprint">
<ul class="topnav">
<li>home</li>
<li>surprise</li>
</ul>
</div>
<div class="content">
<h1>Hello ByCode!</h1>
<div>hello.pl is running!</div>
<img src="/static/images/catalyst_logo.png" />
</div>
</body>
</html>
# 453 characters without white space
DESCRIPTION
`Catalyst::View::ByCode' tries to offer an efficient, fast and robust
solution for generating HTML and XHTML markup using standard perl code
encapsulating all nesting into code blocks.
Instead of typing opening and closing HTML-Tags we simply call a sub
named like the tag we want to generate:
div { 'hello' }
generates:
<div>hello</div>
There is no templating language you will have to learn, no quirks with
different syntax rules your editor might not correctly follow and no
indentation problems.
The whole markup is initially constructed as a huge tree-like structure
in memory keeping every reference as long as possible to allow greatest
flexibility and enable deferred construction of every building block
until the markup is actially requested.
Every part of the markup can use almost every type of data with some
reasonable behavior during markup generation.
Tags
Every tag known in HTML (or defined in HTML::Tagset to be precise) gets
exported to a template's namespace during its compilation and can be
used as expected. However, there are some exceptions which would collide
with CORE subs or operators
choice generates a <select> tag
link_tag generates a <link> tag
trow generates a <tr> tag
tcol generates a <td> tag
subscript generates a <sub> tag
superscript generates a <sup> tag
meta_tag generates a <meta> tag
quote generates a <q> tag
strike generates a <s<gt> tag
map_tag generates a <map> tag
Internally, every tag subroutine is defined with a prototype like
sub div(;&@) { ... }
Thus, the first argument of this sub is expected to be a coderef, which
allows to write code like the examples above. Nesting tags is just a
matter of nesting calls into blocks.
Content
There are several ways to generate content which is inserted between the
opening and the closing tag:
The return value of the last expression of a code block will get
appended to the content inside the tag. The content will get escaped
when needed.
To append any content (getting escaped) at any point of the markup
generation, the `OUT' glob can be used:
print OUT 'some content here.';
To append unescaped content eg JavaScript or the content of another
markup-generating subsystem like `HTML::FormFu' simple use the <RAW>
glob:
print RAW '<?xxx must be here for internal reasons ?>';
Attributes
As usual for Perl, there is always more than one way to do it:
old-school perl
# appending attributes after tag
div { ... content ... } id => 'top',
class => 'noprint silver',
style => 'display: none';
the content goes into the curly-braced code block immediately
following the tag. Every extra argument after the code block is
converted into the tag's attributes.
special content
# using special methods
div {
id 'top';
class 'noprint silver';
attr style => 'display: none';
'content'
};
Every attribute may be added to the latest opened tag using the
`attr' sub. However, there are some shortcuts:
id 'name'
is equivalent to `attr id =' 'name'>
class 'class'
is the same as `attr class =' 'class'>
However, the `class' method is special. It allows to specify
a space-separated string, a list of names or a combination
of both. Class names prefixed with `-' or `+' are treated
special. After a minus prefixed class name every following
name is subtracted from the previous list of class names.
After a plus prefixed name all following names are added to
the class list. A list of class names without a plus/minus
prefix will start with an empty class list and then append
all subsequentially following names.
div.foo { class 'abc def ghi' }; will yield 'abc def ghi'
div.foo { class '+def xyz' }; will yield 'foo def xyz'
div.foo { class '-foo +bar' }; will yield 'bar'
on handler => 'some javascript code'
produces the same result as `attr onhandler =' 'some
javascript code'>
div {
on click => q{alert('you clicked me')};
};
tricky arguments
div top.noprint.silver(style => 'display: none') {'content'};
even more tricky arguments
div top.noprint.silver(style => {display => 'none'}) {'content'};
tricky arguments and CamelCase
div top.noprint.silver(style => {marginTop => '20px'}) {'content'};
`marginTop' or `margin_top' will get converted to `margin-top'.
Every attribute may have almost any datatype you might think of:
scalar
Scalar values are taken verbatim.
hashref
Hash references are converted to semicolon-delimited pairs of the
key, a colon and a value. The perfect solution for building inline
CSS. Well, I know, nobody should do something, but sometimes...
Keys consisting of underscore characters and CAPITAL letters are
converted to dash-separated names. `dataTarget' or `data_target'
both become `data-target'.
arrayref
Array references are converted to space separated things.
coderef -- FIXME: do we like this?
no idea if we like this
other refs
all other references simply are stringified. This allows the various
objects to forward stringification to their class-defined code.
Special Methods
doctype
load
Building Reusable blocks
You might build a reusable block line the following calls:
block 'block_name' => sub { ... };
# or shorter:
block block_name { ... };
The block might get used like a tag:
block_name { ... some content ... };
If a block-call contains a content it can get rendered inside the block
using the special sub `block_content'. A simple example makes this
clearer:
# define a block:
block infobox {
my $headline = attr('headline') || 'untitled';
my $id = attr('id');
my $class = attr('class');
div.infobox {
id $id if ($id);
class $class if ($class);
div.head { $headline };
div.info { block_content };
};
};
# later we use the block:
infobox some_id.someclass(headline => 'Our Info') { 'just my 2 cents' };
# this HTML will get generated:
<div class="someclass" id="some_id">
<div class="head">Our Info</div>
<div class="info">just my 2 cents</div>
</div>
every block defined in a package is auto-added to the packages `@EXPORT'
array and mangled in a special way to make the magic calling syntax work
after importing it into another package.
CONFIGURATION
A simple configuration of a derived Controller could look like this:
__PACKAGE__->config(
# Change extension (default: .pl)
extension => '.pl',
# Set the location for .pl files (default: root/bycode)
root_dir => cat_app->path_to( 'root', 'bycode' ),
# This is your wrapper template located in root_dir (default: wrapper.pl)
wrapper => 'wrapper.pl',
# all these modules are use()'d automatically
include => [Some::Module Another::Package],
);
METHODS
process
fulfill the request (called from Catalyst)
AUTHOR
Wolfgang Kinkeldei, <wolfgang@kinkeldei.de>
LICENSE
This library is free software, you can redistribute it and/or modify it
under the same terms as Perl itself.