—package
Mojo::Template;
use
Mojo::Base -base;
use
Mojo::ByteStream;
use
Mojo::Exception;
has
[
qw(auto_escape compiled)
];
has
[
qw(append code prepend template)
] =>
''
;
has
capture_end
=>
'end'
;
has
capture_start
=>
'begin'
;
has
comment_mark
=>
'#'
;
has
encoding
=>
'UTF-8'
;
has
escape
=>
sub
{ \
&Mojo::Util::xml_escape
};
has
[
qw(escape_mark expression_mark trim_mark)
] =>
'='
;
has
[
qw(line_start replace_mark)
] =>
'%'
;
has
name
=>
'template'
;
has
namespace
=>
'Mojo::Template::SandBox'
;
has
tag_start
=>
'<%'
;
has
tag_end
=>
'%>'
;
has
tree
=>
sub
{ [] };
sub
build {
my
$self
=
shift
;
my
(
@lines
,
$cpst
,
$multi
);
my
$escape
=
$self
->auto_escape;
for
my
$line
(@{
$self
->tree}) {
push
@lines
,
''
;
for
(
my
$j
= 0;
$j
< @{
$line
};
$j
+= 2) {
my
(
$op
,
$value
) =
@$line
[
$j
,
$j
+ 1];
my
$newline
=
chomp
(
$value
//=
''
);
# Capture end
if
(
$op
eq
'cpen'
) {
$lines
[-1] .=
'return Mojo::ByteStream->new($_M) }'
;
# No following code
my
$next
=
$line
->[
$j
+ 3];
$lines
[-1] .=
';'
if
!
defined
$next
||
$next
=~ /^\s*$/;
}
# Text (quote and fix line ending)
if
(
$op
eq
'text'
) {
$value
=
$newline
?
quotemeta
(
$value
) .
'\n'
:
quotemeta
$value
;
$lines
[-1] .=
"\$_M .= \""
.
$value
.
"\";"
if
length
$value
;
}
# Code or multiline expression
if
(
$op
eq
'code'
||
$multi
) {
$lines
[-1] .=
"$value"
}
# Expression
if
(
$op
eq
'expr'
||
$op
eq
'escp'
) {
# Start
unless
(
$multi
) {
# Escaped
if
((
$op
eq
'escp'
&& !
$escape
) || (
$op
eq
'expr'
&&
$escape
)) {
$lines
[-1] .=
"\$_M .= _escape"
;
$lines
[-1] .=
" scalar $value"
if
length
$value
;
}
# Raw
else
{
$lines
[-1] .=
"\$_M .= scalar $value"
}
}
# Multiline
$multi
= !((
$line
->[
$j
+ 2] //
''
) eq
'text'
&& (
$line
->[
$j
+ 3] //
''
) eq
''
);
# Append semicolon
$lines
[-1] .=
';'
unless
$multi
||
$cpst
;
}
# Capture start
if
(
$cpst
) {
$lines
[-1] .=
$cpst
;
$cpst
=
undef
;
}
$cpst
=
" sub { my \$_M = ''; "
if
$op
eq
'cpst'
;
}
}
return
$self
->code(
$self
->_wrap(\
@lines
))->tree([]);
}
sub
compile {
my
$self
=
shift
;
# Compile with line directive
return
undef
unless
my
$code
=
$self
->code;
my
$name
=
$self
->name;
$name
=~ s/"//g;
my
$compiled
=
eval
qq{#line 1 "$name"\n$code}
;
$self
->compiled(
$compiled
) and
return
undef
unless
$@;
# Use local stacktrace for compile exceptions
return
Mojo::Exception->new($@, [
$self
->template,
$code
])->trace->verbose(1);
}
sub
interpret {
my
$self
=
shift
;
# Stacktrace
local
$SIG
{__DIE__} =
sub
{
CORE::
die
(
$_
[0])
if
ref
$_
[0];
Mojo::Exception->throw(
shift
, [
$self
->template,
$self
->code]);
};
return
undef
unless
my
$compiled
=
$self
->compiled;
my
$output
;
return
$output
if
eval
{
$output
=
$compiled
->(
@_
); 1 };
# Exception with template context
return
Mojo::Exception->new($@, [
$self
->template])->verbose(1);
}
sub
parse {
my
(
$self
,
$template
) =
@_
;
# Clean start
my
$tree
=
$self
->template(
$template
)->tree([])->tree;
my
$tag
=
$self
->tag_start;
my
$replace
=
$self
->replace_mark;
my
$expr
=
$self
->expression_mark;
my
$escp
=
$self
->escape_mark;
my
$cpen
=
$self
->capture_end;
my
$cmnt
=
$self
->comment_mark;
my
$cpst
=
$self
->capture_start;
my
$trim
=
$self
->trim_mark;
my
$end
=
$self
->tag_end;
my
$start
=
$self
->line_start;
my
$token_re
=
qr/
(
\Q$tag\E(?:\Q$replace\E|\Q$cmnt\E) # Replace
|
\Q$tag$expr\E(?:\Q$escp\E)?(?:\s*\Q$cpen\E(?!\w))? # Expression
|
\Q$tag\E(?:\s*\Q$cpen\E(?!\w))? # Code
|
(?:(?<!\w)\Q$cpst\E\s*)?(?:\Q$trim\E)?\Q$end\E # End
)
/
x;
my
$cpen_re
=
qr/^(\Q$tag\E)(?:\Q$expr\E)?(?:\Q$escp\E)?\s*\Q$cpen\E/
;
my
$end_re
=
qr/^(?:(\Q$cpst\E)\s*)?(\Q$trim\E)?\Q$end\E$/
;
# Split lines
my
$state
=
'text'
;
my
(
$trimming
,
@capture_token
);
for
my
$line
(
split
/\n/,
$template
) {
$trimming
= 0
if
$state
eq
'text'
;
# Turn Perl line into mixed line
if
(
$state
eq
'text'
&&
$line
!~ s/^(\s*)\Q
$start
$replace
\E/$1
$start
/) {
if
(
$line
=~ s/^(\s*)\Q
$start
\E(?:(\Q
$cmnt
\E)|(\Q
$expr
\E))?//) {
# Comment
if
($2) {
$line
=
"$tag$2 $trim$end"
}
# Expression or code
else
{
$line
= $3 ?
"$1$tag$3$line $end"
:
"$tag$line $trim$end"
}
}
}
# Escaped line ending
$line
.=
"\n"
unless
$line
=~ s/\\\\$/\\\n/ ||
$line
=~ s/\\$//;
# Mixed line
my
@token
;
for
my
$token
(
split
$token_re
,
$line
) {
# Capture end
@capture_token
= (
'cpen'
,
undef
)
if
$token
=~ s/
$cpen_re
/$1/;
# End
if
(
$state
ne
'text'
&&
$token
=~
$end_re
) {
$state
=
'text'
;
# Capture start
splice
@token
, -2, 0,
'cpst'
,
undef
if
$1;
# Trim left side
if
($2) {
$trimming
= 1;
$self
->_trim(\
@token
);
}
# Hint at end
push
@token
,
'text'
,
''
;
}
# Code
elsif
(
$token
=~ /^\Q
$tag
\E$/) {
$state
=
'code'
}
# Expression
elsif
(
$token
=~ /^\Q
$tag
$expr
\E$/) {
$state
=
'expr'
}
# Expression that needs to be escaped
elsif
(
$token
=~ /^\Q
$tag
$expr
$escp
\E$/) {
$state
=
'escp'
}
# Comment
elsif
(
$token
=~ /^\Q
$tag
$cmnt
\E$/) {
$state
=
'cmnt'
}
# Text
else
{
# Replace
$token
=
$tag
if
$token
eq
"$tag$replace"
;
# Trim right side (convert whitespace to line noise)
if
(
$trimming
&&
$token
=~ s/^(\s+)//) {
push
@token
,
'code'
, $1;
$trimming
= 0;
}
# Comments are ignored
next
if
$state
eq
'cmnt'
;
push
@token
,
@capture_token
,
$state
,
$token
;
@capture_token
= ();
}
}
push
@$tree
, \
@token
;
}
return
$self
;
}
sub
render {
my
$self
=
shift
;
return
$self
->parse(
shift
)->build->compile ||
$self
->interpret(
@_
);
}
sub
render_file {
my
(
$self
,
$path
) = (
shift
,
shift
);
$self
->name(
$path
)
unless
defined
$self
->{name};
my
$template
= slurp
$path
;
my
$encoding
=
$self
->encoding;
croak
qq{Template "$path" has invalid encoding.}
if
$encoding
&& !
defined
(
$template
= decode
$encoding
,
$template
);
return
$self
->render(
$template
,
@_
);
}
sub
_trim {
my
(
$self
,
$line
) =
@_
;
# Walk line backwards
for
(
my
$j
=
@$line
- 4;
$j
>= 0;
$j
-= 2) {
# Skip captures
next
if
$line
->[
$j
] eq
'cpst'
||
$line
->[
$j
] eq
'cpen'
;
# Only trim text
return
unless
$line
->[
$j
] eq
'text'
;
# Convert whitespace text to line noise
splice
@$line
,
$j
, 0,
'code'
, $1
if
$line
->[
$j
+ 1] =~ s/(\s+)$//;
# Text left
return
if
length
$line
->[
$j
+ 1];
}
}
sub
_wrap {
my
(
$self
,
$lines
) =
@_
;
# Escape function
my
$escape
=
$self
->escape;
monkey_patch
$self
->namespace,
_escape
=>
sub
{
no
warnings
'uninitialized'
;
ref
$_
[0] eq
'Mojo::ByteStream'
?
$_
[0] :
$escape
->(
"$_[0]"
);
};
# Wrap lines
my
$first
=
$lines
->[0] ||=
''
;
$lines
->[0] =
"package @{[$self->namespace]}; use Mojo::Base -strict;"
;
$lines
->[0] .=
"sub { my \$_M = ''; @{[$self->prepend]}; do { $first"
;
$lines
->[-1] .=
"@{[$self->append]}; \$_M } };"
;
my
$code
=
join
"\n"
,
@$lines
;
warn
"-- Code for @{[$self->name]}\n@{[encode 'UTF-8', $code]}\n\n"
if
DEBUG;
return
$code
;
}
1;
=encoding utf8
=head1 NAME
Mojo::Template - Perl-ish templates!
=head1 SYNOPSIS
use Mojo::Template;
# Simple
my $mt = Mojo::Template->new;
my $output = $mt->render(<<'EOF');
% use Time::Piece;
<!DOCTYPE html>
<html>
<head><title>Simple</title></head>
% my $now = localtime;
<body>Time: <%= $now->hms %></body>
</html>
EOF
say $output;
# More advanced
my $output = $mt->render(<<'EOF', 23, 'foo bar');
% my ($num, $text) = @_;
%= 5 * 5
<!DOCTYPE html>
<html>
<head><title>More advanced</title></head>
<body>
test 123
foo <% my $i = $num + 2; %>
% for (1 .. 23) {
* some text <%= $i++ %>
% }
</body>
</html>
EOF
say $output;
=head1 DESCRIPTION
L<Mojo::Template> is a minimalistic and very Perl-ish template engine,
designed specifically for all those small tasks that come up during big
projects. Like preprocessing a configuration file, generating text from
heredocs and stuff like that.
See L<Mojolicious::Guides::Rendering> for information on how to generate
content with the L<Mojolicious> renderer.
=head1 SYNTAX
For all templates L<strict>, L<warnings>, L<utf8> and Perl 5.10 features are
automatically enabled.
<% Perl code %>
<%= Perl expression, replaced with result %>
<%== Perl expression, replaced with XML escaped result %>
<%# Comment, useful for debugging %>
<%% Replaced with "<%", useful for generating templates %>
% Perl code line, treated as "<% line =%>"
%= Perl expression line, treated as "<%= line %>"
%== Perl expression line, treated as "<%== line %>"
%# Comment line, useful for debugging
%% Replaced with "%", useful for generating templates
Escaping behavior can be reversed with the L</"auto_escape"> attribute, this
is the default in L<Mojolicious> C<.ep> templates for example.
<%= Perl expression, replaced with XML escaped result %>
<%== Perl expression, replaced with result %>
L<Mojo::ByteStream> objects are always excluded from automatic escaping.
% use Mojo::ByteStream 'b';
<%= b('<div>excluded!</div>') %>
Newline characters can be escaped with a backslash.
This is <%= 1 + 1 %> a\
single line
And a backslash in front of a newline character can be escaped with another
backslash.
This will <%= 1 + 1 %> result\\
in multiple\\
lines
Whitespace characters around tags can be trimmed with a special tag ending.
<%= All whitespace characters around this expression will be trimmed =%>
You can capture whole template blocks for reuse later with the C<begin> and
C<end> keywords.
<% my $block = begin %>
<% my $name = shift; =%>
Hello <%= $name %>.
<% end %>
<%= $block->('Baerbel') %>
<%= $block->('Wolfgang') %>
Perl lines can also be indented freely.
% my $block = begin
% my $name = shift;
Hello <%= $name %>.
% end
%= $block->('Baerbel')
%= $block->('Wolfgang')
L<Mojo::Template> templates get compiled to a Perl subroutine, that means you
can access arguments simply via C<@_>.
% my ($foo, $bar) = @_;
% my $x = shift;
test 123 <%= $foo %>
The compilation of templates to Perl code can make debugging a bit tricky, but
L<Mojo::Template> will return L<Mojo::Exception> objects that stringify to
error messages with context.
Bareword "xx" not allowed while "strict subs" in use at template line 4.
2: </head>
3: <body>
4: % my $i = 2; xx
5: %= $i * 2
6: </body>
=head1 ATTRIBUTES
L<Mojo::Template> implements the following attributes.
=head2 auto_escape
my $bool = $mt->auto_escape;
$mt = $mt->auto_escape($bool);
Activate automatic escaping.
=head2 append
my $code = $mt->append;
$mt = $mt->append('warn "Processed template"');
Append Perl code to compiled template. Note that this code should not contain
newline characters, or line numbers in error messages might end up being
wrong.
=head2 capture_end
my $end = $mt->capture_end;
$mt = $mt->capture_end('end');
Keyword indicating the end of a capture block, defaults to C<end>.
<% my $block = begin %>
Some data!
<% end %>
=head2 capture_start
my $start = $mt->capture_start;
$mt = $mt->capture_start('begin');
Keyword indicating the start of a capture block, defaults to C<begin>.
<% my $block = begin %>
Some data!
<% end %>
=head2 code
my $code = $mt->code;
$mt = $mt->code($code);
Perl code for template.
=head2 comment_mark
my $mark = $mt->comment_mark;
$mt = $mt->comment_mark('#');
Character indicating the start of a comment, defaults to C<#>.
<%# This is a comment %>
=head2 compiled
my $compiled = $mt->compiled;
$mt = $mt->compiled($compiled);
Compiled template code.
=head2 encoding
my $encoding = $mt->encoding;
$mt = $mt->encoding('UTF-8');
Encoding used for template files.
=head2 escape
my $cb = $mt->escape;
$mt = $mt->escape(sub { reverse $_[0] });
A callback used to escape the results of escaped expressions, defaults to
L<Mojo::Util/"xml_escape">.
=head2 escape_mark
my $mark = $mt->escape_mark;
$mt = $mt->escape_mark('=');
Character indicating the start of an escaped expression, defaults to C<=>.
<%== $foo %>
=head2 expression_mark
my $mark = $mt->expression_mark;
$mt = $mt->expression_mark('=');
Character indicating the start of an expression, defaults to C<=>.
<%= $foo %>
=head2 line_start
my $start = $mt->line_start;
$mt = $mt->line_start('%');
Character indicating the start of a code line, defaults to C<%>.
% $foo = 23;
=head2 name
my $name = $mt->name;
$mt = $mt->name('foo.mt');
Name of template currently being processed, defaults to C<template>. Note that
this value should not contain quotes or newline characters, or error messages
might end up being wrong.
=head2 namespace
my $namespace = $mt->namespace;
$mt = $mt->namespace('main');
Namespace used to compile templates, defaults to C<Mojo::Template::SandBox>.
Note that namespaces should only be shared very carefully between templates,
since functions and global variables will not be cleared automatically.
=head2 prepend
my $code = $mt->prepend;
$mt = $mt->prepend('my $self = shift;');
Prepend Perl code to compiled template. Note that this code should not contain
newline characters, or line numbers in error messages might end up being
wrong.
=head2 replace_mark
my $mark = $mt->replace_mark;
$mt = $mt->replace_mark('%');
Character used for escaping the start of a tag or line, defaults to C<%>.
<%% my $foo = 23; %>
=head2 tag_start
my $start = $mt->tag_start;
$mt = $mt->tag_start('<%');
Characters indicating the start of a tag, defaults to C<E<lt>%>.
<% $foo = 23; %>
=head2 tag_end
my $end = $mt->tag_end;
$mt = $mt->tag_end('%>');
Characters indicating the end of a tag, defaults to C<%E<gt>>.
<%= $foo %>
=head2 template
my $template = $mt->template;
$mt = $mt->template($template);
Raw unparsed template.
=head2 tree
my $tree = $mt->tree;
$mt = $mt->tree([['text', 'foo']]);
Template in parsed form. Note that this structure should only be used very
carefully since it is very dynamic.
=head2 trim_mark
my $mark = $mt->trim_mark;
$mt = $mt->trim_mark('-');
Character activating automatic whitespace trimming, defaults to C<=>.
<%= $foo =%>
=head1 METHODS
L<Mojo::Template> inherits all methods from L<Mojo::Base> and implements the
following new ones.
=head2 build
$mt = $mt->build;
Build Perl L</"code"> from L</"tree">.
=head2 compile
my $exception = $mt->compile;
Compile Perl L</"code"> for template.
=head2 interpret
my $output = $mt->interpret;
my $output = $mt->interpret(@args);
Interpret L</"compiled"> template code.
# Reuse template
say $mt->render('Hello <%= $_[0] %>!', 'Bender');
say $mt->interpret('Fry');
say $mt->interpret('Leela');
=head2 parse
$mt = $mt->parse($template);
Parse template into L</"tree">.
=head2 render
my $output = $mt->render($template);
my $output = $mt->render($template, @args);
Render template.
say $mt->render('Hello <%= $_[0] %>!', 'Bender');
=head2 render_file
my $output = $mt->render_file('/tmp/foo.mt');
my $output = $mt->render_file('/tmp/foo.mt', @args);
Render template file.
=head1 DEBUGGING
You can set the MOJO_TEMPLATE_DEBUG environment variable to get some advanced
diagnostics information printed to C<STDERR>.
MOJO_TEMPLATE_DEBUG=1
=head1 SEE ALSO
L<Mojolicious>, L<Mojolicious::Guides>, L<http://mojolicio.us>.
=cut