NAME
Mustache::Simple - A simple Mustache Renderer
See
http://mustache.github.com/.
VERSION
This document describes Mustache::Simple version 1.3.0
SYNOPSIS
A typical Mustache template:
my $template = <<EOT;
Hello {{name}}
You have just won ${{value}}!
{{#in_ca}}
Well, ${{taxed_value}}, after taxes.
{{/in_ca}}
EOT
Given the following hashref:
my $context = {
name => "Chris",
value => 10000,
taxed_value => 10000 - (10000 * 0.4),
in_ca => 1
};
Will produce the following:
Hello Chris
You have just won $10000!
Well, $6000, after taxes.
using the following code:
my $tache = new Mustache::Simple(
throw => 1
);
my $output = $tache->render($template, $context);
DESCRIPTION
Mustache can be used for HTML, config files, source code - anything. It
works by expanding tags in a template using values provided in a hash or
object.
There are no if statements, else clauses, or for loops. Instead there
are only tags. Some tags are replaced with a value, some nothing, and
others a series of values.
This is a simple perl implementation of the Mustache rendering. It has a
single class method, new() to obtain an object and a single instance
method render() to convert the template and the hashref into the final
output.
As of version 1.2.0, it has support for nested contexts, for the dot
notation and for the implicit iterator.
As of version 1.3.0, it will accept a blessed object. For any `{{item}}'
where the object has a method called item (as returned by
`$object->can'), the value will be the return from the method call (with
no parameters). If `$object->can(item)' returns `undef', the object will
be treated as a hash and the value looked up directly. See MANAGING
OBJECTS below.
Rationale
I wanted a simple rendering tool for Mustache that did not require any
subclassing.
METHODS
Creating a new Mustache::Simple object
new
my $tache = new Mustache::Simple(%options)
Parameters:
path
The path from which to load templates and partials. This may be a
string or a reference to an array of strings. If it is a reference,
each string will be searched in order.
Default: '.'
extension
The extension to add to filenames when reading them off disk. The
'.' should not be included as this will be added automatically.
Default: 'mustache'
throw
If set to a true value, Mustache::Simple will croak when there is no
key in the context hash for a given tag.
Default: undef
partial
This may be set to a subroutine to be called to generate the
filename or the template for a partial. If it is not set, partials
will be loaded using the same parameters as render().
Default: undef
Configuration Methods
The configuration methods match the %options array thay may be passed to
new().
Each option may be called with a non-false value to set the option and
will return the new value. If called without a value, it will return the
current value.
path()
$tache->path('/some/new/template/path');
or
$tache->path([ qw{/some/new/template/path .} ]);
my $path = $tache->path; # defaults to '.'
extension()
$tache->extension('html');
my $extension = $tache->extension; # defaults to 'mustache'
throw()
$tache->throw(1);
my $throwing = $tache->throw; # defaults to undef
partial()
$tache->partial(\&resolve_partials)
my $partial = $tache->partial # defaults to undef
Instance methods
read_file()
my $template = read_file('templatefile');
You will not usually need to call this directly as it's called by
render to load the file. If it is passed a string that looks like a
template (i.e. has {{ in it) it simply returns it. Similarly, if,
after prepending the path and adding the suffix, it cannot load the
file, it simply returns the original string.
render()
my $context = {
"name" => "Chris",
"value" => 10000,
"taxed_value" => 10000 - (10000 * 0.4),
"in_ca" => true
}
my $html = $tache->render('templatefile', $context);
This is the main entry-point for rendering templates. It can be
passed either a full template or path to a template file. See
read_file for details of how the file is loaded. It must also be
passed a hashref containing the main context.
In callbacks (sections like ` {{#this}} ' with a subroutine in the
context), you may call render on the passed string and the current
context will be remembered. For example:
{
name => "Willy",
wrapped => sub {
my $text = shift;
chomp $text;
return "<b>" . $tache->render($text) . "</b>\n";
}
}
Alternatively, you may pass in an entirely new context when calling
render() from a callback.
COMPLIANCE WITH THE STANDARD
The original standard for Mustache was defined at the Mustache Manual
and this version of Mustache::Simple was designed to comply with just
that. Since then, the standard for Mustache seems to be defined by the
Mustache Spec.
The test suite on this version skips a number of tests in the Spec, all
of which relate to Decimals or White Space. It passes all the other
tests. The YAML from the Spec is built into the test suite.
MANAGING OBJECTS
If a blessed object is passed in (at any level) as the context for
rendering a template, Mustache::Simple will check each tag to see if it
can be called as a method on the object. To achieve this, it calls `can'
from UNIVERSAL on the object. If `$object->can(tag)' returns code, this
code will be called (with no parameters). Otherwise, if the object is
based on an underlying HASH, it will be treated as that HASH. This works
well for objects with AUTOLOADed "getters".
For example:
package Test::Mustache;
sub new
{
my $class = shift;
my %params = @_;
bless \%params, $class;
}
sub name # Ensure the name starts with a capital
{
my $self = shift;
(my $name = $self->{name}) =~ s/.*/\L\u$&/;
return $name;
}
sub AUTOLOAD # generic getter / setter
{
my $self = shift;
my $value = shift;
(my $method = our $AUTOLOAD) =~ s/.*:://;
$self->{$method} = $value if defined $value;
return $self->{$method};
}
sub DESTROY { }
Using the above object as `$object', `{{name}}' would call
`$object->can('name')' which would return a reference to the `name'
method and thus that method would be called as a "getter". On a call to
`{{address}}', `$object->can' would return undef and therefore
`$object->{address}' would be used.
This is usually what you want as it avoids the call to
`$object->AUTOLOAD' for each simple lookup. If, however, you want
something different to happen, you either need to declare a "Forward
Declaration" (see perlsub) or you need to override the object's `can'
(see UNIVERSAL).
BUGS
White Space
Much of the more esoteric white-space handling specified in The
Mustache Spec is not strictly adhered to in this version. Most of
this will be addressed in a future version.
Because of this, the following tests from the Mustache Spec are
skipped:
* Indented Inline
* Indented Inline Sections
* Internal Whitespace
* Standalone Indentation
* Standalone Indented Lines
* Standalone Line Endings
* Standalone Without Newline
* Standalone Without Previous Line
Decimal Interpolation
The spec implies that the template `"{{power}} jiggawatts!"' when
passed `{ power: "1.210" }' should return `"1.21 jiggawatts!"'. I
believe this to be wrong and simply a mistake in the YAML of the
relevant tests or possibly in YAML::XS. I am far from being a YAML
expert.
Clearly `{ power : 1.210 }' would have the desired effect.
Because of this, all tests matching `/Decimal/' have been skipped.
We can just assume that Perl will do the right thing.
EXPORTS
Nothing.
SEE ALSO
Template::Mustache - a much more complex module that is designed to be
subclassed for each template.
AUTHOR INFORMATION
Cliff Stanford `<
[email protected]>'
SOURCE REPOSITORY
The source is maintained at a public Github repository at
https://github.com/CliffS/mustache-simple. Feel free to fork it and to
help me fix some of the above issues. Please leave any bugs or issues on
the Issues page and I will be notified.
LICENCE AND COPYRIGHT
Copyright © 2014, Cliff Stanford `<
[email protected]>'. All rights reserved.
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
