LIQUID MARKUP - Meetupfiles.meetup.com/1397868/Liquid-Markup.pdf · When Should I use Liquid When...

LIQUID MARKUPA story by Dane Harrigan

Friday, March 11, 2011

I’m Dane Harrigan

@daneharrigan

What is Liquid

When Should I use Liquid

What is Liquid

How do I use Liquid

What is Liquid

How do I use Liquid

Liquify: Liquid Simplified

What is Liquid

•Template Language

What is Liquid

•Written in Ruby

What is Liquid

•Written in Ruby

•Similar to ERb

What is Liquid

<%= %>

ERb Liquid

What is Liquid

<%= %>

ERb Liquid

<% %> {% %}

What is Liquid

<%= %>

ERb Liquid

<% %> {% %}

<%= helper(val) %> {{ val | helper }}

What is Liquid

•Secure

What is Liquid

•Secure

•Does Not Evaluate Ruby

What is Liquid

•Secure

•Does Not Evaluate Ruby

•Is a Pain in The Ass to Use

“Ok, so why would I use it?”

When to use Liquid

When NOT to use Liquid

“1%? Now I’m interested!”

When you’re sharing your view code

•Shopping Carts (Shopify)

•Newsletter Services (MailChimp)

•CMS (Magnetism, Mephisto, Jekyll)

When you need a limited feature set

•Only allow access to specific objects

•Specify which methods of an object can be executed

•Allow usage of predefined helper methods

“Huh?”

How do I use Liquid

•Drops (Classes, Models)

How do I use Liquid

•Filters (View Helpers)

How do I use Liquid

•Filters (View Helpers)

•Tags (Single Purpose Classes)

“Show me some code already!”

# person_drop.rbclass PersonDrop < Liquid::Drop def first_name "Dane" end def last_name "Harrigan" endend

# app/models/person.rbclass Person < ActiveRecord::Baseliquid_methods :first_name, :last_name

# rendering a liquid templatetemplate = Liquid::Template.parse(tmpl_code)template.render(:person => PersonDrop.new)

<body> <h1>{{ person.first_name }} {{ person.last_name }}</h1></body>

“Ok, what about filters?”

# my_filters.rbmodule MyFilters def greet(name) "Hello #{name}!" end def goodbye(name) "Goodbye #{name}!" endend

# rendering a liquid templateLiquid::Template.register_filter MyFilters

template = Liquid::Template.parse(tmpl_code)template.render(:person => PersonDrop.new)

# rendering a liquid templateLiquid::Template.register_filter MyFilters

<body> <h1>{{ person.first_name | greet }}</h1></body>

“Way easy. Tags please.”

<body> {% foo "bar", "cux" %} <h1>{{ person.first_name | greet }}</h1></body>

# rendering a liquid templateLiquid::Template.register_tag 'foo', FooTag

# foo_tag.rbclass FooTag < Liquid::Tag def render(context) @markup # => '"bar", "cux"' context # => {'person' => PersonDrop.new}

# logic for your foo tag endend

# foo_tag.rbclass FooTag < Liquid::Tag def render(context) @markup # => '"bar", "cux"' context # => {'person' => PersonDrop.new}

# logic for your foo tag endend

“Ok, real example please?”

<!DOCTYPE HTML><html> <body> {% snippet 'header' %} <h1>{{ person.first_name | greet }}</h1> {% snippet 'footer' %} </body></html>

# rendering a liquid templateLiquid::Template.register_tag 'snippet', SnippetTag

# snippet_tag.rbclass SnippetTag < Liquid::Tag def render(context) name = @markup.gsub(/("|')/,'').strip

tmpl = Template.snippets.first_by_name(name) content = tmpl.content

template = Liquid::Template.parse(content) template.render(:person => PersonDrop.new) endend

“Can this actually get easier?”

•Register Drops, Filters and Tags in one Place

•Improvements to liquid_methods

•Auto-parsed Parameters

# register tagLiquid::Template.register_tag 'foo', FooTag

# register filtersLiquid::Template.register_filter BarFilters

# register droptmpl = Liquid::Template.parse(template_code)tmpl.render(:person => PersonDrop.new)

“I’m dying to see Liquify!”

Liquify.setup do |config| config.register_tag :foo, FooTag config.register_filter BarFilters config.register_drop :person, PersonDrop

# need access to stuff later? config.register_drop :person, lambda { PersonDrop.first }end

Liquify.invoke(template_code)

“Sweet!”

class Person < ActiveRecord::Base liquify_methods :first_name, :last_name, :full_name => lambda { |p| "#{p.first_name} #{p.last_name}" }end

“I approve.”

<body> <h1>{{ person.first_name | greet }}</h1> {% snippet 'profile', item: person, class: 'active' %}</body>

class SnippetTag < Liquify::Tag def invoke(params) params # => ['profile', { # 'item' => PersonDrop.new, # 'class' => 'active'} # ] endend

class SnippetTag < Liquify::Tag def invoke # don't need params? endend

“You’ve changed my life.”

I’m Dane Harrigan

Thanks

Twitter: @daneharrigan

Github: daneharrigan

gem install liquify

LIQUID MARKUP - Meetupfiles.meetup.com/1397868/Liquid-Markup.pdf · When Should I use Liquid When...

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