From f5a6d16466fd528171002a137440e9d99eb9129a Mon Sep 17 00:00:00 2001
From: Jesse Luehrs <doy@tozt.net>
Date: Tue, 2 Oct 2012 17:33:57 -0500
Subject: implement ../

---
 lib/Text/Handlebars.pm               |  8 +++++++-
 lib/Text/Xslate/Syntax/Handlebars.pm | 16 ++++++++++++++++
 t/expressions.t                      | 16 ++++++++++++++--
 3 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/lib/Text/Handlebars.pm b/lib/Text/Handlebars.pm
index aa239a0..c58ae86 100644
--- a/lib/Text/Handlebars.pm
+++ b/lib/Text/Handlebars.pm
@@ -4,6 +4,8 @@ use warnings;
 
 use base 'Text::Xslate';
 
+use Scalar::Util 'weaken';
+
 sub default_functions {
     my $class = shift;
     return {
@@ -35,7 +37,11 @@ sub default_functions {
                 die "invalid value: $value"
                     if !defined($ref) || $ref ne 'HASH';
 
-                return $value;
+                weaken(my $vars_copy = $vars);
+                return {
+                    %$value,
+                    '..' => $vars_copy,
+                };
             }
             else {
                 return $vars;
diff --git a/lib/Text/Xslate/Syntax/Handlebars.pm b/lib/Text/Xslate/Syntax/Handlebars.pm
index 3537952..9bd1366 100644
--- a/lib/Text/Xslate/Syntax/Handlebars.pm
+++ b/lib/Text/Xslate/Syntax/Handlebars.pm
@@ -148,6 +148,7 @@ sub init_symbols {
     $self->prefix('/', 0)->is_block_end(1);
 
     $self->prefix('&', 0)->set_nud($self->can('nud_mark_raw'));
+    $self->prefix('..', 0)->set_nud($self->can('nud_uplevel'));
 }
 
 sub nud_name {
@@ -290,6 +291,13 @@ sub nud_mark_raw {
     return $self->call('mark_raw', $self->expression(0));
 }
 
+sub nud_uplevel {
+    my $self = shift;
+    my ($symbol) = @_;
+
+    return $symbol->clone(arity => 'variable');
+}
+
 sub make_field_lookup {
     my $self = shift;
     my ($var, $field, $dot) = @_;
@@ -307,6 +315,14 @@ sub make_field_lookup {
     );
 }
 
+sub is_valid_field {
+    my $self = shift;
+    my ($field) = @_;
+
+    return 1 if $field->id eq '..';
+    return $self->SUPER::is_valid_field(@_);
+}
+
 sub make_ternary {
     my $self = shift;
     my ($if, $then, $else) = @_;
diff --git a/t/expressions.t b/t/expressions.t
index 02b1b3a..c2e928c 100644
--- a/t/expressions.t
+++ b/t/expressions.t
@@ -26,7 +26,18 @@ render_ok(
     "/ separator"
 );
 
-{ local $TODO = "unimplemented";
+render_ok(
+    '<h1>{{page.article.title}}</h1> - {{date}}',
+    {
+        page => {
+            article => { title => 'Multilevel field access' },
+        },
+        date => '2012-10-01',
+    },
+    '<h1>Multilevel field access</h1> - 2012-10-01',
+    "multilevel field access with ."
+);
+
 render_ok(
     '{{#article}}<h1>{{title}}</h1> - {{../date}}{{/article}}',
     { article => { title => 'Backtracking' }, date => '2012-10-01' },
@@ -34,6 +45,7 @@ render_ok(
     "backtracking with ../"
 );
 
+{ local $TODO = "autochomping issues";
 render_ok(
     <<'TEMPLATE',
 {{#page}}
@@ -51,6 +63,7 @@ TEMPLATE
 RENDERED
     "multilevel backtracking with ../"
 );
+}
 
 render_ok(
     '{{#article}}<h1>{{title}}</h1> - {{../metadata.date}}{{/article}}',
@@ -61,6 +74,5 @@ render_ok(
     '<h1>Backtracking</h1> - 2012-10-01',
     "backtracking into other hash variables with ../ and ."
 );
-}
 
 done_testing;
-- 
cgit v1.2.3-54-g00ecf