class Mustache::Generator
The Generator is in charge of taking an array of Mustache tokens, usually assembled by the Parser, and generating an interpolatable Ruby string. This string is considered the “compiled” template because at that point we're relying on Ruby to do the parsing and run our code.
For example, let's take this template:
Hi {{thing}}!
If we run this through the Parser we'll get these tokens:
[:multi, [:static, "Hi "], [:mustache, :etag, "thing"], [:static, "!\n"]]
Now let's hand that to the Generator:
>> puts ::new.compile(tokens) “Hi #{CGI.escapeHTML(ctx.to_s)}!n”
You can see the generated Ruby string for any template with the mustache(1) command line tool:
$ mustache --compile test.mustache "Hi #{CGI.escapeHTML(ctx[:thing].to_s)}!\n"
Public Class Methods
Options are unused for now but may become useful in the future.
# File lib/mustache/generator.rb, line 31 def initialize(options = {}) @options = options end
Public Instance Methods
Given an array of tokens, returns an interpolatable Ruby string.
# File lib/mustache/generator.rb, line 36 def compile(exp) "\"#{compile!(exp)}\"" end
Private Instance Methods
Given an array of tokens, converts them into Ruby code. In particular there are three types of expressions we are concerned with:
:multi Mixed bag of :static, :mustache, and whatever. :static Normal HTML, the stuff outside of {{mustaches}}. :mustache Any Mustache tag, from sections to partials.
To give you an idea of what you'll be dealing with take this template:
Hello {{name}} You have just won ${{value}}! {{#in_ca}} Well, ${{taxed_value}}, after taxes. {{/in_ca}}
If we run this through the Parser, we'll get back this array of tokens:
[:multi, [:static, "Hello "], [:mustache, :etag, [:mustache, :fetch, ["name"]]], [:static, "\nYou have just won $"], [:mustache, :etag, [:mustache, :fetch, ["value"]]], [:static, "!\n"], [:mustache, :section, [:mustache, :fetch, ["in_ca"]], [:multi, [:static, "Well, $"], [:mustache, :etag, [:mustache, :fetch, ["taxed_value"]]], [:static, ", after taxes.\n"]], "Well, ${{taxed_value}}, after taxes.\n", ["{{", "}}"]]]
# File lib/mustache/generator.rb, line 87 def compile!(exp) case exp.first when :multi exp[1..-1].reduce("") { |sum, e| sum << compile!(e) } when :static str(exp[1]) when :mustache send("on_#{exp[1]}", *exp[2..-1]) else raise "Unhandled exp: #{exp.first}" end end
An interpolation-friendly version of a string, for use within a Ruby string.
# File lib/mustache/generator.rb, line 192 def ev(s) "#\{#{s}}" end
An escaped tag.
# File lib/mustache/generator.rb, line 167 def on_etag(name, offset) ev(<<-compiled) v = #{compile!(name)} if v.is_a?(Proc) v = Mustache::Template.new(v.call.to_s).render(ctx.dup) end ctx.escapeHTML(v.to_s) compiled end
# File lib/mustache/generator.rb, line 177 def on_fetch(names) return "ctx.current" if names.empty? names = names.map { |n| n.to_sym } initial, *rest = names <<-compiled #{rest.inspect}.reduce(ctx[#{initial.inspect}]) { |value, key| value && ctx.find(value, key) } compiled end
Fired when we find an inverted section. Just like `on_section`, we're passed the inverted section name and the array of tokens.
# File lib/mustache/generator.rb, line 133 def on_inverted_section(name, offset, content, raw, delims) # Convert the tokenized content of this section into a Ruby # string we can use. code = compile(content) # Compile the Ruby for this inverted section now that we know # what's inside. ev(<<-compiled) v = #{compile!(name)} if v.nil? || v == false || v.respond_to?(:empty?) && v.empty? #{code} end compiled end
Fired when the compiler finds a partial. We want to return code which calls a partial at runtime instead of expanding and including the partial's body to allow for recursive partials.
# File lib/mustache/generator.rb, line 151 def on_partial(name, offset, indentation) ev("ctx.partial(#{name.to_sym.inspect}, #{indentation.inspect})") end
Callback fired when the compiler finds a section token. We're passed the section name and the array of tokens.
# File lib/mustache/generator.rb, line 102 def on_section(name, offset, content, raw, delims) # Convert the tokenized content of this section into a Ruby # string we can use. code = compile(content) # Compile the Ruby for this section now that we know what's # inside the section. ev(<<-compiled) if v = #{compile!(name)} if v == true #{code} elsif v.is_a?(Proc) t = Mustache::Template.new(v.call(#{raw.inspect}).to_s) def t.tokens(src=@source) p = Parser.new p.otag, p.ctag = #{delims.inspect} p.compile(src) end t.render(ctx.dup) else # Shortcut when passed non-array v = [v] unless v.is_a?(Array) || v.is_a?(Mustache::Enumerable) || defined?(Enumerator) && v.is_a?(Enumerator) v.map { |h| ctx.push(h); r = #{code}; ctx.pop; r }.join end end compiled end
An unescaped tag.
# File lib/mustache/generator.rb, line 156 def on_utag(name, offset) ev(<<-compiled) v = #{compile!(name)} if v.is_a?(Proc) v = Mustache::Template.new(v.call.to_s).render(ctx.dup) end v.to_s compiled end
# File lib/mustache/generator.rb, line 196 def str(s) s.inspect[1..-2] end