added support for template variants

mojolicious · Mar 12, 2014 · a385e46 · a385e46
1 parent defc52f
commit a385e46
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Showing 6 changed files with 85 additions and 21 deletions.
diff --git a/Changes b/Changes
@@ -1,5 +1,6 @@
 
 4.89  2014-03-12
+  - Added support for template variants.
   - Fixed bug in Mojo::DOM::HTML where non-self-closing elements were not
     handled correctly.
   - Fixed bug in Mojo::DOM::HTML where <image> was not treated as an alias for

diff --git a/lib/Mojolicious/Controller.pm b/lib/Mojolicious/Controller.pm
@@ -21,7 +21,7 @@ has tx => sub { Mojo::Transaction::HTTP->new };
 # Reserved stash values
 my %RESERVED = map { $_ => 1 } (
   qw(action app cb controller data extends format handler json layout),
-  qw(namespace partial path status template text)
+  qw(namespace partial path status template text variant)
 );
 
 sub AUTOLOAD {
@@ -884,8 +884,8 @@ wide default values can be set with L<Mojolicious/"defaults">. Some stash
 values have a special meaning and are reserved, the full list is currently
 C<action>, C<app>, C<cb>, C<controller>, C<data>, C<extends>, C<format>,
 C<handler>, C<json>, C<layout>, C<namespace>, C<partial>, C<path>, C<status>,
-C<template> and C<text>. Note that all stash values with a C<mojo.*> prefix
-are reserved for internal use.
+C<template>, C<text> and C<variant>. Note that all stash values with a
+C<mojo.*> prefix are reserved for internal use.
 
   # Remove value
   my $foo = delete $c->stash->{foo};

diff --git a/lib/Mojolicious/Guides/Rendering.pod b/lib/Mojolicious/Guides/Rendering.pod
@@ -198,6 +198,16 @@ alternatives.
 
   $self->render_maybe('localized/baz') or $self->render('foo/bar/baz');
 
+=head2 Template variants
+
+To make your application look great on many different devices you can also
+select a C<variant> for your templates, it only applies when a template with
+the correct name actually exists and falls back to the generic one otherwise.
+
+  # foo.html+phone.ep
+  # foo.html.ep
+  $self->render('foo', format => 'html', variant => 'phone', handler => 'ep');
+
 =head2 Rendering inline templates
 
 Some renderers such as C<ep> allow templates to be passed inline.

diff --git a/lib/Mojolicious/Renderer.pm b/lib/Mojolicious/Renderer.pm
@@ -84,7 +84,8 @@ sub render {
   my $options = {
     encoding => $self->encoding,
     handler  => $stash->{handler},
-    template => delete $stash->{template}
+    template => delete $stash->{template},
+    variant  => $stash->{variant}
   };
   my $inline = $options->{inline} = delete $stash->{inline};
   $options->{handler} //= $self->default_handler if defined $inline;
@@ -149,30 +150,28 @@ sub template_for {
 
 sub template_handler {
   my ($self, $options) = @_;
-
   return undef unless my $file = $self->template_name($options);
-  unless ($self->{templates}) {
-
-    # Templates
-    s/\.(\w+)$// and $self->{templates}{$_} ||= $1
-      for map { sort @{Mojo::Home->new($_)->list_files} } @{$self->paths};
-
-    # DATA templates
-    my $loader = Mojo::Loader->new;
-    s/\.(\w+)$// and $self->{templates}{$_} ||= $1
-      for map { sort keys %{$loader->data($_)} } @{$self->classes};
-  }
-
-  return $self->{templates}{$file} if exists $self->{templates}{$file};
-  return $self->default_handler;
+  return $self->default_handler unless my $handlers = $self->_handlers($file);
+  return $handlers->[0];
 }
 
 sub template_name {
   my ($self, $options) = @_;
+
   return undef unless my $template = $options->{template};
   return undef unless my $format   = $options->{format};
+  $template .= ".$format";
+
+  # Variants
   my $handler = $options->{handler};
-  return defined $handler ? "$template.$format.$handler" : "$template.$format";
+  if (defined(my $variant = $options->{variant})) {
+    $variant = "$template+$variant";
+    my $handlers = $self->_handlers($variant) // [];
+    $template = $variant
+      if @$handlers && !defined $handler || grep { $_ eq $handler } @$handlers;
+  }
+
+  return defined $handler ? "$template.$handler" : $template;
 }
 
 sub template_path {
@@ -206,6 +205,24 @@ sub _extends {
   return delete $stash->{extends};
 }
 
+sub _handlers {
+  my ($self, $file) = @_;
+
+  unless ($self->{templates}) {
+
+    # Templates
+    s/\.(\w+)$// and push @{$self->{templates}{$_}}, $1
+      for map { sort @{Mojo::Home->new($_)->list_files} } @{$self->paths};
+
+    # DATA templates
+    my $loader = Mojo::Loader->new;
+    s/\.(\w+)$// and push @{$self->{templates}{$_}}, $1
+      for map { sort keys %{$loader->data($_)} } @{$self->classes};
+  }
+
+  return $self->{templates}{$file};
+}
+
 sub _render_template {
   my ($self, $c, $output, $options) = @_;
 

diff --git a/t/mojolicious/dispatch.t b/t/mojolicious/dispatch.t
@@ -96,7 +96,8 @@ is $c->param(path    => 'test')->param('path'),    undef, 'value is reserved';
 is $c->param(status  => 'test')->param('status'),  undef, 'value is reserved';
 is $c->param(template => 'test')->param('template'), undef,
   'value is reserved';
-is $c->param(text => 'test')->param('text'), undef, 'value is reserved';
+is $c->param(text    => 'test')->param('text'),    undef, 'value is reserved';
+is $c->param(variant => 'test')->param('variant'), undef, 'value is reserved';
 is_deeply [$c->param], [], 'values are hidden';
 
 # Controller with application and routes

diff --git a/t/mojolicious/layouted_lite_app.t b/t/mojolicious/layouted_lite_app.t
@@ -106,6 +106,12 @@ get '/inline/again' => {inline => 0};
 
 get '/data' => {data => 0};
 
+get '/variants' => {layout => 'variants'} => sub {
+  my $self = shift;
+  $self->stash->{variant} = $self->param('device');
+  $self->render('variants');
+};
+
 my $t = Test::Mojo->new;
 
 # "0" content reassignment
@@ -245,6 +251,23 @@ $t->get_ok('/inline/again')->status_is(200)
 $t->get_ok('/data')->status_is(200)->header_is(Server => 'Mojolicious (Perl)')
   ->content_is(0);
 
+# Variants (desktop)
+$t->get_ok('/variants')->status_is(200)
+  ->header_is(Server => 'Mojolicious (Perl)')->content_is('Variant: Desktop!');
+
+# Variants (tablet)
+$t->get_ok('/variants?device=tablet')->status_is(200)
+  ->header_is(Server => 'Mojolicious (Perl)')->content_is('Variant: Tablet!');
+
+# Variants (desktop fallback)
+$t->get_ok('/variants?device=phone')->status_is(200)
+  ->header_is(Server => 'Mojolicious (Perl)')->content_is('Variant: Desktop!');
+
+# Variants ("0")
+$t->get_ok('/variants?device=0')->status_is(200)
+  ->header_is(Server => 'Mojolicious (Perl)')
+  ->content_is('Another variant: Desktop!');
+
 done_testing();
 
 __DATA__
@@ -375,3 +398,15 @@ seems
 to
 <%= content_for 'message' %>
 work!
+
+@@ layouts/variants.html.ep
+Variant: <%= content %>\
+
+@@ layouts/variants.html+0.ep
+Another variant: <%= content %>\
+
+@@ variants.html.ep
+Desktop!\
+
+@@ variants.html+tablet.epl
+Tablet!\