class ActionView::Template

Action View Template

Attributes

format[R]
handler[R]
identifier[R]
locals[R]
original_encoding[R]
updated_at[R]
variable[R]
variant[R]
virtual_path[R]

Public Class Methods

finalize_compiled_template_methods() click to toggle source
# File lib/action_view/template.rb, line 13
def self.finalize_compiled_template_methods
  ActiveSupport::Deprecation.warn "ActionView::Template.finalize_compiled_template_methods is deprecated and has no effect"
end
finalize_compiled_template_methods=(_) click to toggle source
# File lib/action_view/template.rb, line 17
def self.finalize_compiled_template_methods=(_)
  ActiveSupport::Deprecation.warn "ActionView::Template.finalize_compiled_template_methods= is deprecated and has no effect"
end
new(source, identifier, handler, format: nil, variant: nil, locals: nil, virtual_path: nil, updated_at: nil) click to toggle source
# File lib/action_view/template.rb, line 129
def initialize(source, identifier, handler, format: nil, variant: nil, locals: nil, virtual_path: nil, updated_at: nil)
  unless locals
    ActiveSupport::Deprecation.warn "ActionView::Template#initialize requires a locals parameter"
    locals = []
  end

  @source            = source
  @identifier        = identifier
  @handler           = handler
  @compiled          = false
  @locals            = locals
  @virtual_path      = virtual_path

  @variable = if @virtual_path
    base = @virtual_path[-1] == "/" ? "" : ::File.basename(@virtual_path)
    base =~ /\A_?(.*?)(?:\.\w+)*\z/
    $1.to_sym
  end

  if updated_at
    ActiveSupport::Deprecation.warn "ActionView::Template#updated_at is deprecated"
    @updated_at        = updated_at
  else
    @updated_at        = Time.now
  end
  @format            = format
  @variant           = variant
  @compile_mutex     = Mutex.new
end

Public Instance Methods

encode!() click to toggle source

This method is responsible for properly setting the encoding of the source. Until this point, we assume that the source is BINARY data. If no additional information is supplied, we assume the encoding is the same as Encoding.default_external.

The user can also specify the encoding via a comment on the first line of the template (# encoding: NAME-OF-ENCODING). This will work with any template engine, as we process out the encoding comment before passing the source on to the template engine, leaving a blank line in its stead.

# File lib/action_view/template.rb, line 216
def encode!
  source = self.source

  return source unless source.encoding == Encoding::BINARY

  # Look for # encoding: *. If we find one, we'll encode the
  # String in that encoding, otherwise, we'll use the
  # default external encoding.
  if source.sub!(/\A#{ENCODING_FLAG}/, "")
    encoding = magic_encoding = $1
  else
    encoding = Encoding.default_external
  end

  # Tag the source with the default external encoding
  # or the encoding specified in the file
  source.force_encoding(encoding)

  # If the user didn't specify an encoding, and the handler
  # handles encodings, we simply pass the String as is to
  # the handler (with the default_external tag)
  if !magic_encoding && @handler.respond_to?(:handles_encoding?) && @handler.handles_encoding?
    source
  # Otherwise, if the String is valid in the encoding,
  # encode immediately to default_internal. This means
  # that if a handler doesn't handle encodings, it will
  # always get Strings in the default_internal
  elsif source.valid_encoding?
    source.encode!
  # Otherwise, since the String is invalid in the encoding
  # specified, raise an exception
  else
    raise WrongEncodingError.new(source, encoding)
  end
end
formats() click to toggle source
# File lib/action_view/template.rb, line 164
def formats; Array(format); end
formats=(_) click to toggle source
# File lib/action_view/template.rb, line 163
def formats=(_); end
inspect() click to toggle source
# File lib/action_view/template.rb, line 198
def inspect
  "#<#{self.class.name} #{short_identifier} locals=#{@locals.inspect}>"
end
local_assigns() click to toggle source

Returns a hash with the defined local variables.

Given this sub template rendering:

<%= render "shared/header", { headline: "Welcome", person: person } %>

You can use local_assigns in the sub templates to access the local variables:

local_assigns[:headline] # => "Welcome"
# File lib/action_view/template.rb, line 113
eager_autoload do
  autoload :Error
  autoload :RawFile
  autoload :Handlers
  autoload :HTML
  autoload :Inline
  autoload :Sources
  autoload :Text
  autoload :Types
end
locals=(_) click to toggle source
# File lib/action_view/template.rb, line 162
def locals=(_); end
refresh(_) click to toggle source
# File lib/action_view/template.rb, line 167
def refresh(_); self; end
render(view, locals, buffer = ActionView::OutputBuffer.new, &block) click to toggle source

Render a template. If the template was not compiled yet, it is done exactly before rendering.

This method is instrumented as “!render_template.action_view”. Notice that we use a bang in this instrumentation because you don't want to consume this in production. This is only slow if it's being listened to.

# File lib/action_view/template.rb, line 181
def render(view, locals, buffer = ActionView::OutputBuffer.new, &block)
  instrument_render_template do
    compile!(view)
    view._run(method_name, self, locals, buffer, &block)
  end
rescue => e
  handle_render_error(view, e)
end
short_identifier() click to toggle source
# File lib/action_view/template.rb, line 194
def short_identifier
  @short_identifier ||= defined?(Rails.root) ? identifier.sub("#{Rails.root}/", "") : identifier
end
source() click to toggle source
# File lib/action_view/template.rb, line 202
def source
  @source.to_s
end
supports_streaming?() click to toggle source

Returns whether the underlying handler supports streaming. If so, a streaming buffer may be passed when it starts rendering.

# File lib/action_view/template.rb, line 171
def supports_streaming?
  handler.respond_to?(:supports_streaming?) && handler.supports_streaming?
end
type() click to toggle source
# File lib/action_view/template.rb, line 190
def type
  @type ||= Types[format]
end
variants() click to toggle source
# File lib/action_view/template.rb, line 166
def variants; [variant]; end
variants=(_) click to toggle source
# File lib/action_view/template.rb, line 165
def variants=(_); end
virtual_path=(_) click to toggle source
# File lib/action_view/template.rb, line 161
def virtual_path=(_); end

Private Instance Methods

compile(mod) click to toggle source

Among other things, this method is responsible for properly setting the encoding of the compiled template.

If the template engine handles encodings, we send the encoded String to the engine without further processing. This allows the template engine to support additional mechanisms for specifying the encoding. For instance, ERB supports <%# encoding: %>

Otherwise, after we figure out the correct encoding, we then encode the source into Encoding.default_internal. In general, this means that templates will be UTF-8 inside of Rails, regardless of the original source encoding.

# File lib/action_view/template.rb, line 311
def compile(mod)
  source = encode!
  code = @handler.call(self, source)

  # Make sure that the resulting String to be eval'd is in the
  # encoding of the code
  original_source = source
  source = +<<-end_src
compile!(view) click to toggle source

Compile a template. This method ensures a template is compiled just once and removes the source after it is compiled.

# File lib/action_view/template.rb, line 268
def compile!(view)
  return if @compiled

  # Templates can be used concurrently in threaded environments
  # so compilation and any instance variable modification must
  # be synchronized
  @compile_mutex.synchronize do
    # Any thread holding this lock will be compiling the template needed
    # by the threads waiting. So re-check the @compiled flag to avoid
    # re-compilation
    return if @compiled

    mod = view.compiled_method_container

    instrument("!compile_template") do
      compile(mod)
    end

    @compiled = true
  end
end