Class: ERB
- Inherits:
-
Object
- Object
- ERB
- Defined in:
- lib/erb.rb,
lib/erb.rb,
lib/erb.rb,
lib/erb.rb,
lib/erb.rb
Overview
– ERB::DefMethod
Defined Under Namespace
Modules: DefMethod, Util Classes: Compiler
Constant Summary collapse
- Revision =
:nodoc: #‘
'$Date:: 2015-12-20 15:36:57 +0900#$'
Instance Attribute Summary collapse
-
#encoding ⇒ Object
readonly
The encoding to eval.
-
#filename ⇒ Object
The optional filename argument passed to Kernel#eval when the ERB code is run.
-
#lineno ⇒ Object
The optional lineno argument passed to Kernel#eval when the ERB code is run.
-
#src ⇒ Object
readonly
The Ruby code generated by ERB.
Class Method Summary collapse
-
.version ⇒ Object
Returns revision information for the erb.rb module.
Instance Method Summary collapse
-
#def_class(superklass = Object, methodname = 'result') ⇒ Object
Define unnamed class which has methodname as instance method, and return it.
-
#def_method(mod, methodname, fname = '(ERB)') ⇒ Object
Define methodname as instance method of mod from compiled Ruby source.
-
#def_module(methodname = 'erb') ⇒ Object
Create unnamed module, define methodname as instance method of it, and return it.
-
#initialize(str, safe_level = nil, trim_mode = nil, eoutvar = '_erbout') ⇒ ERB
constructor
Constructs a new ERB object with the template specified in str.
- #location=(filename, lineno) ⇒ Object
-
#make_compiler(trim_mode) ⇒ Object
Creates a new compiler for ERB.
-
#result(b = new_toplevel) ⇒ Object
Executes the generated ERB code to produce a completed template, returning the results of that code.
-
#run(b = new_toplevel) ⇒ Object
Generate results and print them.
-
#set_eoutvar(compiler, eoutvar = '_erbout') ⇒ Object
Can be used to set eoutvar as described in ERB::new.
Constructor Details
#initialize(str, safe_level = nil, trim_mode = nil, eoutvar = '_erbout') ⇒ ERB
Constructs a new ERB object with the template specified in str.
An ERB 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, ERB 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, ERB 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 %>
- omit blank lines ending in -%>
eoutvar can be used to set the name of the variable ERB will build up its output in. This is useful when you need to run multiple ERB 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 variables
ERB.new(<<-'END_PRODUCT'.gsub(/^\s+/, ""), 0, "", "@product").result b
<%= PRODUCT[:name] %>
<%= PRODUCT[:desc] %>
END_PRODUCT
ERB.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.
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# File 'lib/erb.rb', line 797 def initialize(str, safe_level=nil, trim_mode=nil, eoutvar='_erbout') @safe_level = safe_level compiler = make_compiler(trim_mode) set_eoutvar(compiler, eoutvar) @src, @encoding = *compiler.compile(str) @filename = nil @lineno = 0 end |
Instance Attribute Details
#encoding ⇒ Object (readonly)
The encoding to eval
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# File 'lib/erb.rb', line 817 def encoding @encoding end |
#filename ⇒ Object
The optional filename argument passed to Kernel#eval when the ERB code is run
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# File 'lib/erb.rb', line 821 def filename @filename end |
#lineno ⇒ Object
The optional lineno argument passed to Kernel#eval when the ERB code is run
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# File 'lib/erb.rb', line 825 def lineno @lineno end |
#src ⇒ Object (readonly)
The Ruby code generated by ERB
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# File 'lib/erb.rb', line 814 def src @src end |
Class Method Details
Instance Method Details
#def_class(superklass = Object, methodname = 'result') ⇒ Object
Define unnamed class which has methodname as instance method, and return it.
example:
class MyClass_
def initialize(arg1, arg2)
@arg1 = arg1; @arg2 = arg2
end
end
filename = 'example.rhtml' # @arg1 and @arg2 are used in example.rhtml
erb = ERB.new(File.read(filename))
erb.filename = filename
MyClass = erb.def_class(MyClass_, 'render()')
print MyClass.new('foo', 123).render()
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# File 'lib/erb.rb', line 921 def def_class(superklass=Object, methodname='result') cls = Class.new(superklass) def_method(cls, methodname, @filename || '(ERB)') cls end |
#def_method(mod, methodname, fname = '(ERB)') ⇒ Object
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# File 'lib/erb.rb', line 884 def def_method(mod, methodname, fname='(ERB)') src = self.src magic_comment = "#coding:#{@encoding}\n" mod.module_eval do eval(magic_comment + "def #{methodname}\n" + src + "\nend\n", binding, fname, -2) end end |
#def_module(methodname = 'erb') ⇒ Object
Create unnamed module, define methodname as instance method of it, and return it.
example:
filename = 'example.rhtml' # 'arg1' and 'arg2' are used in example.rhtml
erb = ERB.new(File.read(filename))
erb.filename = filename
MyModule = erb.def_module('render(arg1, arg2)')
class MyClass
include MyModule
end
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# File 'lib/erb.rb', line 902 def def_module(methodname='erb') mod = Module.new def_method(mod, methodname, @filename || '(ERB)') mod end |
#location=(filename, lineno) ⇒ Object
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# File 'lib/erb.rb', line 827 def location=((filename, lineno)) @filename = filename @lineno = lineno if lineno end |
#make_compiler(trim_mode) ⇒ Object
Creates a new compiler for ERB. See ERB::Compiler.new for details
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# File 'lib/erb.rb', line 809 def make_compiler(trim_mode) ERB::Compiler.new(trim_mode) end |
#result(b = new_toplevel) ⇒ Object
Executes the generated ERB code to produce a completed template, returning the results of that code. (See ERB::new for details on how this process can be affected by safe_level.)
b accepts a Binding object which is used to set the context of code evaluation.
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# File 'lib/erb.rb', line 857 def result(b=new_toplevel) if @safe_level proc { $SAFE = @safe_level eval(@src, b, (@filename || '(erb)'), @lineno) }.call else eval(@src, b, (@filename || '(erb)'), @lineno) end end |
#run(b = new_toplevel) ⇒ Object
Generate results and print them. (see ERB#result)
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# File 'lib/erb.rb', line 845 def run(b=new_toplevel) print self.result(b) end |
#set_eoutvar(compiler, eoutvar = '_erbout') ⇒ Object
Can be used to set eoutvar as described in ERB::new. It’s probably easier to just use the constructor though, since calling this method requires the setup of an ERB compiler object.
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# File 'lib/erb.rb', line 837 def set_eoutvar(compiler, eoutvar = '_erbout') compiler.put_cmd = "#{eoutvar}.concat" compiler.insert_cmd = "#{eoutvar}.concat" compiler.pre_cmd = ["#{eoutvar} = ''"] compiler.post_cmd = ["#{eoutvar}.force_encoding(__ENCODING__)"] end |