Class: Booster::Template

Inherits:
Tilt::Template
  • Object
show all
Defined in:
lib/booster/template.rb

Overview

Tilt integration which pre-processes ‘.booster` files by wrapping them in a CommonJS-like closure and converts inline templates to JavaScript functions using the Handlebars compiler. While it is at it, it also does string interpolation on regular JavaScript strings.

Constant Summary collapse

TEMPLATE_SECTION =

Regex for capturing sections of template code to be compiled to JavaScript

/@@\s*([A-Za-z0-9]*)\n(((?!@@).)*)/m
STRING_INTERPOLATION =

Regex for capturing string interpolations STRING_INTERPOLATION = /(‘|“)(.*)#([sS]+?)/

/#\{([\s\S]+?)\}/

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.default_mime_type ⇒ Object

Processing Booster files result in plain JavaScript.



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# File 'lib/booster/template.rb', line 20

def self.default_mime_type
  'application/javascript'
end

Instance Method Details

#evaluate(scope, locals, &block) ⇒ Object 



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# File 'lib/booster/template.rb', line 24

def evaluate(scope, locals, &block)
  # Replace template code with compiled JavaScript
  data.gsub!(TEMPLATE_SECTION) do
    "var #{$1} = Handlebars.template(#{Handlebars.precompile($2.strip!)});\n\n"
  end

  # Convert string interpolation to string concatenation with rudimentary
  # guessing of quote type ($1). Since the template functions compiled in the
  # previous step are just functions it is possible to use interpolations there
  # as well, even if Handlebars does not support them by default. This is not
  # recommended though although it works.
  data.gsub!(STRING_INTERPOLATION, '\' + (\1) + \'')

  # Indent the module content if in development mode for increased readability
  if (Rails.env == 'development')
    data.gsub!(/^(.)/, '  \1')
  end

  # Wrap the whole thing in a closure and register it as a module (https://gist.github.com/1153919)
  @output ||= "require.define({'#{ module_name(scope) }': function(exports, require, module) {#{data}}});\n"
end