テンプレートの静的解析とリファクタリング

Talk at テンプレートエンジン Night

1. ςϯϓϨʔτͷ! ੩తղੳͱ! ϦϑΝΫλϦϯά! ! id:aereal
2. ࣗݾ঺հ • id:aereal • aereal.org • Hatena • Web
3. ΞδΣϯμ •Web ΞϓϦέʔγϣϯͱςϯϓϨʔτ Τϯδϯ •Text::Xslate ͱ੩తղੳ •՝୊ͱల๬
4. ςϯϓϨʔτΤϯδϯ •Template::Toolkit •Text::MicroMason •HTML::Template • Text::Xslate
5. Web ΞϓϦέʔγϣϯ ͱςϯϓϨʔτΤϯδϯ
6. ౤ߘΛදࣔ͢Δ! ૉ๿ͳςϯϓϨʔτ
7. post.tt <h1>[% post.title %]</h1> <div class="body">[% post.body %]</div>
8. ίϯτϩʔϥ $c->render('post.tt', { post => $post });
9. ʮ౤ߘΛҰཡදࣔ͠Α͏ʯ
10. •ςϯϓϨʔτΛϞδϡʔϧԽ •post.tt → _post.tt •posts/index.tt → _post.tt •posts/show.tt → _post.tt
11. ʮҰཡͰ͸ຊจΛ! লུ͍ͨ͠ʯ
12. _post.tt [%- SET formatted = with_ellipsis ? (post.body | truncate) : post.body %] <h1>[% post.title %]</h1> <div class="body">[% formatted %]</div>
13. ਺िؒޙ……
14. index.tt [% INCLUDE "_post.tt" WITH with_ellipsis = 1, show_social_buttons = 1, ... ... show_category = 1, %]
15. INCLUDE ͢Δͱ͖ʹ! ԿΛ౉ͤ͹Α͍ͷ͔! Θ͔Βͳ͍
16. ʮίϝϯτʹॻ͜͏ʯ
17. _post.tt [%# post, show_social_buttons, show_category, ... %] ...
18. ΍΍ॿ͔ͬͨ
19. ࣌͸ྲྀΕͨɺ͋Δ೔
20. ίϝϯτ่յ •_post.tt Ͱ blog ͕ඞཁʹͳͬͨ •index.tt Ͱ͸ blog ͕ఆٛࡁΈͩͬͨ •_post.tt ʹίϝϯτ͕௥ه͞Εͳ͔ͬͨ
21. _post.tt <div class="post" data-blog-id="[% blog.id %]"> ... </div>
22. index.tt [%# blog %] ... [% FOR post IN posts %] [% INCLUDE "_post.tt" WITH blog = blog, ... %] [% END %]
23. ΋͏μϝͩ
24. ͦΕ੩తղੳͰ
25. ͳͥ੩తղੳ •نଇ͕͋ΔͷͰϓϩάϥϜͷಘҙ෼໺ •Text::Xslate ʹ͸Ϧονͳ API ͕͋Δ
26. ొ৔ਓ෺ •Text::Xslate::Parser •(Text::Xslate::Syntax::*) •Text::Xslate::Symbol •Text::Xslate::AST::Walker ˑ
27. Text::Xslate::Parser •࣮ࡍʹ࢖͏ͷ͸αϒΫϥε •e.g. Text::Xslate::Syntax::TTerse •Text::Xslate::Parser#parse •AST ͕ಘΒΕΔ •AST = [ Text::Xslate::Symbol ]
28. T::X::Parser my $template = "my name is [% name %]"; my $parser = Text::Xslate::Syntax::TTerse->new; my $ast = $parser->parse($template);
29. Text::Xslate::Symbol •#arity •ࣜͷछྨ(?) •e.g. print, literal
30. Text::Xslate::Symbol •#id •ࣝผࢠ •e.g. name
31. Text::Xslate::Symbol •#first #second •Φϖϥϯυ͕ฦΔ •#is_value ͳͲ
32. ม਺Ͱ͋ΔτʔΫϯ grep { $_->arity eq 'variable' } @$ast
33. ΋͏ͪΐͬͱஸೡʹ •໦ߏ଄ͳͷͰ࠶ؼతʹ୳͞ͳ͍ͱ͍͚ͳ ͍ •#first #second
34. Text::Xslate::AST::Walker https://github.com/aereal/Text-Xslate-AST-Walker
35. ະఆٛͷม਺͕ͳ͍ ͜ͱΛظ଴͢ΔσϞ
36. ՝୊ •INCLUDE ͢Δ࣌ʹ౉͢ύϥϝʔλͷ໊લ΋ະ ఆٛʹݟ͑ͯ͠·͏ •અ͕୅ೖ (assign) ͩͬͨΒεΩοϓ͢Ε͹Α ͦ͞͏ •#traverse Έ͍ͨͳϝιουΛ࣮૷͍ͯ͠· ͢ •(inspired by Path::Class::Dir#traverse)
37. ύϥϝʔλͷ໊લ [% INCLUDE "..." WITH post = post %] ~~~~
38. ՝୊ •ϦϑΝΫλϦϯά΋ࣗಈԽ͍ͨ͠ •→ ந৅తͰ͸ͳ͍ߏจ໦͕ཉ͍͠
39. ׬