<@= @desc @>
# ## <@ if @cost < 10 @> # Only <@= @cost @>!!! # <@ else @> # Call for a price, today! # <@ end @> #
# # # # }.gsub(/^ /, '') # # rhtml = CustomERB.new(template) # # # Set up template data. # toy = Product.new( "TZ-1002", # "Rubysapien", # "Geek's Best Friend! Responds to Ruby commands...", # 999.95 ) # toy.add_feature("Listens for verbal commands in the Ruby language!") # toy.add_feature("Ignores Perl, Java, and all C variants.") # toy.add_feature("Karate-Chop Action!!!") # toy.add_feature("Matz signature on left leg.") # toy.add_feature("Gem studded eyes... Rubies, of course!") # # # Produce result. # rhtml.run(toy.get_binding) # # Generates (some blank lines removed): # # #Geek's Best Friend! Responds to Ruby commands...
# ## Call for a price, today! #
# # # # # # == Notes # # There are a variety of templating solutions available in various Ruby projects: # * CustomERB's big brother, eRuby, works the same but is written in C for speed; # * Amrita (smart at producing HTML/XML); # * cs/Template (written in C for speed); # * RDoc, distributed with Ruby, uses its own template engine, which can be reused elsewhere; # * and others; search the RAA. # # Rails, the web application framework, uses CustomERB to create views. # class CustomERB Revision = '$Date: 2007-02-13 08:01:19 +0900 (Tue, 13 Feb 2007) $' #' # Returns revision information for the erb.rb module. def self.version "erb.rb [2.0.4 #{CustomERB::Revision.split[1]}]" end end #-- # CustomERB::Compiler class CustomERB class Compiler # :nodoc: class PercentLine # :nodoc: def initialize(str) @value = str end attr_reader :value alias :to_s :value end class Scanner # :nodoc: SplitRegexp = /(<@@)|(@@>)|(<@=)|(<@#)|(<@)|(@>)|(\n)/ @scanner_map = {} def self.regist_scanner(klass, trim_mode, percent) @scanner_map[[trim_mode, percent]] = klass end def self.default_scanner=(klass) @default_scanner = klass end def self.make_scanner(src, trim_mode, percent) klass = @scanner_map.fetch([trim_mode, percent], @default_scanner) klass.new(src, trim_mode, percent) end def initialize(src, trim_mode, percent) @src = src @stag = nil end attr_accessor :stag def scan; end end class TrimScanner < Scanner # :nodoc: TrimSplitRegexp = /(<@@)|(@@>)|(<@=)|(<@#)|(<@)|(@>\n)|(@>)|(\n)/ def initialize(src, trim_mode, percent) super @trim_mode = trim_mode @percent = percent if @trim_mode == '>' @scan_line = self.method(:trim_line1) elsif @trim_mode == '<>' @scan_line = self.method(:trim_line2) elsif @trim_mode == '-' @scan_line = self.method(:explicit_trim_line) else @scan_line = self.method(:scan_line) end end attr_accessor :stag def scan(&block) @stag = nil if @percent @src.each do |line| percent_line(line, &block) end else @src.each do |line| @scan_line.call(line, &block) end end nil end def percent_line(line, &block) if @stag || line[0] != ?@ return @scan_line.call(line, &block) end line[0] = '' if line[0] == ?@ @scan_line.call(line, &block) else yield(PercentLine.new(line.chomp)) end end def scan_line(line) line.split(SplitRegexp).each do |token| next if token.empty? yield(token) end end def trim_line1(line) line.split(TrimSplitRegexp).each do |token| next if token.empty? if token == "@>\n" yield('@>') yield(:cr) break end yield(token) end end def trim_line2(line) head = nil line.split(TrimSplitRegexp).each do |token| next if token.empty? head = token unless head if token == "@>\n" yield('@>') if is_erb_stag?(head) yield(:cr) else yield("\n") end break end yield(token) end end ExplicitTrimRegexp = /(^[ \t]*<@-)|(-@>\n?\z)|(<@-)|(-@>)|(<@@)|(@@>)|(<@=)|(<@#)|(<@)|(@>)|(\n)/ def explicit_trim_line(line) line.split(ExplicitTrimRegexp).each do |token| next if token.empty? if @stag.nil? && /[ \t]*<@-/ =~ token yield('<@') elsif @stag && /-@>\n/ =~ token yield('@>') yield(:cr) elsif @stag && token == '-@>' yield('@>') else yield(token) end end end CustomERB_STAG = %w(<@= <@# <@) def is_erb_stag?(s) CustomERB_STAG.member?(s) end end Scanner.default_scanner = TrimScanner class SimpleScanner < Scanner # :nodoc: def scan @src.each do |line| line.split(SplitRegexp).each do |token| next if token.empty? yield(token) end end end end Scanner.regist_scanner(SimpleScanner, nil, false) begin require 'strscan' class SimpleScanner2 < Scanner # :nodoc: def scan stag_reg = /(.*?)(<@@|<@=|<@#|<@|\n|\z)/ etag_reg = /(.*?)(@@>|@>|\n|\z)/ scanner = StringScanner.new(@src) while ! scanner.eos? scanner.scan(@stag ? etag_reg : stag_reg) text = scanner[1] elem = scanner[2] yield(text) unless text.empty? yield(elem) unless elem.empty? end end end Scanner.regist_scanner(SimpleScanner2, nil, false) class PercentScanner < Scanner # :nodoc: def scan new_line = true stag_reg = /(.*?)(<@@|<@=|<@#|<@|\n|\z)/ etag_reg = /(.*?)(@@>|@>|\n|\z)/ scanner = StringScanner.new(@src) while ! scanner.eos? if new_line && @stag.nil? if scanner.scan(/@@/) yield('@') new_line = false next elsif scanner.scan(/@/) yield(PercentLine.new(scanner.scan(/.*?(\n|\z)/).chomp)) next end end scanner.scan(@stag ? etag_reg : stag_reg) text = scanner[1] elem = scanner[2] yield(text) unless text.empty? yield(elem) unless elem.empty? new_line = (elem == "\n") end end end Scanner.regist_scanner(PercentScanner, nil, true) class ExplicitScanner < Scanner # :nodoc: def scan new_line = true stag_reg = /(.*?)(<@@|<@=|<@#|<@-|<@|\n|\z)/ etag_reg = /(.*?)(@@>|-@>|@>|\n|\z)/ scanner = StringScanner.new(@src) while ! scanner.eos? if new_line && @stag.nil? && scanner.scan(/[ \t]*<@-/) yield('<@') new_line = false next end scanner.scan(@stag ? etag_reg : stag_reg) text = scanner[1] elem = scanner[2] new_line = (elem == "\n") yield(text) unless text.empty? if elem == '-@>' yield('@>') if scanner.scan(/(\n|\z)/) yield(:cr) new_line = true end elsif elem == '<@-' yield('<@') else yield(elem) unless elem.empty? end end end end Scanner.regist_scanner(ExplicitScanner, '-', false) rescue LoadError end class Buffer # :nodoc: def initialize(compiler) @compiler = compiler @line = [] @script = "" @compiler.pre_cmd.each do |x| push(x) end end attr_reader :script def push(cmd) @line << cmd end def cr @script << (@line.join('; ')) @line = [] @script << "\n" end def close return unless @line @compiler.post_cmd.each do |x| push(x) end @script << (@line.join('; ')) @line = nil end end def compile(s) out = Buffer.new(self) content = '' scanner = make_scanner(s) scanner.scan do |token| if scanner.stag.nil? case token when PercentLine out.push("#{@put_cmd} #{content.dump}") if content.size > 0 content = '' out.push(token.to_s) out.cr when :cr out.cr when '<@', '<@=', '<@#' scanner.stag = token out.push("#{@put_cmd} #{content.dump}") if content.size > 0 content = '' when "\n" content << "\n" out.push("#{@put_cmd} #{content.dump}") out.cr content = '' when '<@@' content << '<@' else content << token end else case token when '@>' case scanner.stag when '<@' if content[-1] == ?\n content.chop! out.push(content) out.cr else out.push(content) end when '<@=' out.push("#{@insert_cmd}((#{content}).to_s)") when '<@#' # out.push("# #{content.dump}") end scanner.stag = nil content = '' when '@@>' content << '@>' else content << token end end end out.push("#{@put_cmd} #{content.dump}") if content.size > 0 out.close out.script end def prepare_trim_mode(mode) case mode when 1 return [false, '>'] when 2 return [false, '<>'] when 0 return [false, nil] when String perc = mode.include?('@') if mode.include?('-') return [perc, '-'] elsif mode.include?('<>') return [perc, '<>'] elsif mode.include?('>') return [perc, '>'] else [perc, nil] end else return [false, nil] end end def make_scanner(src) Scanner.make_scanner(src, @trim_mode, @percent) end def initialize(trim_mode) @percent, @trim_mode = prepare_trim_mode(trim_mode) @put_cmd = 'print' @insert_cmd = @put_cmd @pre_cmd = [] @post_cmd = [] end attr_reader :percent, :trim_mode attr_accessor :put_cmd, :insert_cmd, :pre_cmd, :post_cmd end end #-- # CustomERB class CustomERB # # Constructs a new CustomERB object with the template specified in _str_. # # An CustomERB object works by building a chunk of Ruby code that will output # the completed template when run. If _safe_level_ is set to a non-nil value, # CustomERB code will be run in a separate thread with $SAFE set to the # provided level. # # If _trim_mode_ is passed a String containing one or more of the following # modifiers, CustomERB will adjust its code generation as listed: # # @ enables Ruby code processing for lines beginning with @ # <> omit newline for lines starting with <@ and ending in @> # > omit newline for lines ending in @> # # _eoutvar_ can be used to set the name of the variable CustomERB will build up # its output in. This is useful when you need to run multiple CustomERB # templates through the same binding and/or when you want to control where # output ends up. Pass the name of the variable to be used inside a String. # # === Example # # require "erb" # # # build data class # class Listings # PRODUCT = { :name => "Chicken Fried Steak", # :desc => "A well messages pattie, breaded and fried.", # :cost => 9.95 } # # attr_reader :product, :price # # def initialize( product = "", price = "" ) # @product = product # @price = price # end # # def build # b = binding # # create and run templates, filling member data variebles # CustomERB.new(<<-'END_PRODUCT'.gsub(/^\s+/, ""), 0, "", "@product").result b # <@= PRODUCT[:name] @> # <@= PRODUCT[:desc] @> # END_PRODUCT # CustomERB.new(<<-'END_PRICE'.gsub(/^\s+/, ""), 0, "", "@price").result b # <@= PRODUCT[:name] @> -- <@= PRODUCT[:cost] @> # <@= PRODUCT[:desc] @> # END_PRICE # end # end # # # setup template data # listings = Listings.new # listings.build # # puts listings.product + "\n" + listings.price # # _Generates_ # # Chicken Fried Steak # A well messages pattie, breaded and fried. # # Chicken Fried Steak -- 9.95 # A well messages pattie, breaded and fried. # def initialize(str, safe_level=nil, trim_mode=nil, eoutvar='_erbout') @safe_level = safe_level compiler = CustomERB::Compiler.new(trim_mode) set_eoutvar(compiler, eoutvar) @src = compiler.compile(str) @filename = nil end # The Ruby code generated by CustomERB attr_reader :src # The optional _filename_ argument passed to Kernel#eval when the CustomERB code # is run attr_accessor :filename # # Can be used to set _eoutvar_ as described in CustomERB#new. It's probably easier # to just use the constructor though, since calling this method requires the # setup of an CustomERB _compiler_ object. # def set_eoutvar(compiler, eoutvar = '_erbout') compiler.put_cmd = "#{eoutvar}.concat" compiler.insert_cmd = "#{eoutvar}.concat" cmd = [] cmd.push "#{eoutvar} = ''" compiler.pre_cmd = cmd cmd = [] cmd.push(eoutvar) compiler.post_cmd = cmd end # Generate results and print them. (see CustomERB#result) def run(b=TOPLEVEL_BINDING) print self.result(b) end # # Executes the generated CustomERB code to produce a completed template, returning # the results of that code. (See CustomERB#new for details on how this process can # be affected by _safe_level_.) # # _b_ accepts a Binding or Proc object which is used to set the context of # code evaluation. # def result(b=TOPLEVEL_BINDING) if @safe_level th = Thread.start { $SAFE = @safe_level eval(@src, b, (@filename || '(erb)'), 1) } return th.value else return eval(@src, b, (@filename || '(erb)'), 1) end end def def_method(mod, methodname, fname='(CustomERB)') # :nodoc: mod.module_eval("def #{methodname}\n" + self.src + "\nend\n", fname, 0) end def def_module(methodname='erb') # :nodoc: mod = Module.new def_method(mod, methodname) mod end def def_class(superklass=Object, methodname='result') # :nodoc: cls = Class.new(superklass) def_method(cls, methodname) cls end end #-- # CustomERB::Util class CustomERB # A utility module for conversion routines, often handy in HTML generation. module Util public # # A utility method for escaping HTML tag characters in _s_. # # require "erb" # include CustomERB::Util # # puts html_escape("is a > 0 & a < 10?") # # _Generates_ # # is a > 0 & a < 10? # def html_escape(s) s.to_s.gsub(/&/, "&").gsub(/\"/, """).gsub(/>/, ">").gsub(/, "<") end alias h html_escape module_function :h module_function :html_escape # # A utility method for encoding the String _s_ as a URL. # # require "erb" # include CustomERB::Util # # puts url_encode("Programming Ruby: The Pragmatic Programmer's Guide") # # _Generates_ # # Programming@20Ruby@3A@20@20The@20Pragmatic@20Programmer@27s@20Guide # def url_encode(s) s.to_s.gsub(/[^a-zA-Z0-9_\-.]/n){ sprintf("@@@02X", $&.unpack("C")[0]) } end alias u url_encode module_function :u module_function :url_encode end end #-- # CustomERB::DefMethod class CustomERB module DefMethod # :nodoc: public def def_erb_method(methodname, erb) if erb.kind_of? String fname = erb File.open(fname) {|f| erb = CustomERB.new(f.read) } erb.def_method(self, methodname, fname) else erb.def_method(self, methodname) end end module_function :def_erb_method end end