Module: ActionDispatch::Http::MimeNegotiation

Extended by:
ActiveSupport::Concern
Included in:
Request
Defined in:
actionpack/lib/action_dispatch/http/mime_negotiation.rb

Constant Summary collapse

RESCUABLE_MIME_FORMAT_ERRORS =
[
  ActionController::BadRequest,
  ActionDispatch::Http::Parameters::ParseError,
]

Instance Method Summary collapse

Methods included from ActiveSupport::Concern

append_features, class_methods, extended, included, prepend_features, prepended

Instance Method Details

#acceptsObject

Returns the accepted MIME type for the request.


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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 40

def accepts
  fetch_header("action_dispatch.request.accepts") do |k|
    header = get_header("HTTP_ACCEPT").to_s.strip

    v = if header.empty?
      [content_mime_type]
    else
      Mime::Type.parse(header)
    end
    set_header k, v
  end
end

#content_mime_typeObject

The MIME type of the HTTP request, such as Mime.


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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 20

def content_mime_type
  fetch_header("action_dispatch.request.content_type") do |k|
    v = if get_header("CONTENT_TYPE") =~ /^([^,\;]*)/
      Mime::Type.lookup($1.strip.downcase)
    else
      nil
    end
    set_header k, v
  end
end

#content_typeObject


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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 31

def content_type
  content_mime_type && content_mime_type.to_s
end

#format(view_path = []) ⇒ Object

Returns the MIME type for the format used in the request.

GET /posts/5.xml   | request.format => Mime[:xml]
GET /posts/5.xhtml | request.format => Mime[:html]
GET /posts/5       | request.format => Mime[:html] or Mime[:js], or request.accepts.first

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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 59

def format(view_path = [])
  formats.first || Mime::NullType.instance
end

#format=(extension) ⇒ Object

Sets the format by string extension, which can be used to force custom formats that are not controlled by the extension.

class ApplicationController < ActionController::Base
  before_action :adjust_format_for_iphone

  private
    def adjust_format_for_iphone
      request.format = :iphone if request.env["HTTP_USER_AGENT"][/iPhone/]
    end
end

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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 111

def format=(extension)
  parameters[:format] = extension.to_s
  set_header "action_dispatch.request.formats", [Mime::Type.lookup_by_extension(parameters[:format])]
end

#formatsObject


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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 63

def formats
  fetch_header("action_dispatch.request.formats") do |k|
    v = if params_readable?
      Array(Mime[parameters[:format]])
    elsif use_accept_header && valid_accept_header
      accepts
    elsif extension_format = format_from_path_extension
      [extension_format]
    elsif xhr?
      [Mime[:js]]
    else
      [Mime[:html]]
    end

    v = v.select do |format|
      format.symbol || format.ref == "*/*"
    end

    set_header k, v
  end
end

#formats=(extensions) ⇒ Object

Sets the formats by string extensions. This differs from #format= by allowing you to set multiple, ordered formats, which is useful when you want to have a fallback.

In this example, the :iphone format will be used if it's available, otherwise it'll fallback to the :html format.

class ApplicationController < ActionController::Base
  before_action :adjust_format_for_iphone_with_html_fallback

  private
    def adjust_format_for_iphone_with_html_fallback
      request.formats = [ :iphone, :html ] if request.env["HTTP_USER_AGENT"][/iPhone/]
    end
end

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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 130

def formats=(extensions)
  parameters[:format] = extensions.first.to_s
  set_header "action_dispatch.request.formats", extensions.collect { |extension|
    Mime::Type.lookup_by_extension(extension)
  }
end

#has_content_type?Boolean

:nodoc:

Returns:

  • (Boolean)

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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 35

def has_content_type? # :nodoc:
  get_header "CONTENT_TYPE"
end

#negotiate_mime(order) ⇒ Object

Returns the first MIME type that matches the provided array of MIME types.


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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 138

def negotiate_mime(order)
  formats.each do |priority|
    if priority == Mime::ALL
      return order.first
    elsif order.include?(priority)
      return priority
    end
  end

  order.include?(Mime::ALL) ? format : nil
end

#should_apply_vary_header?Boolean

Returns:

  • (Boolean)

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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 150

def should_apply_vary_header?
  !params_readable? && use_accept_header && valid_accept_header
end

#variantObject


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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 96

def variant
  @variant ||= ActiveSupport::ArrayInquirer.new
end

#variant=(variant) ⇒ Object

Sets the variant for template.


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# File 'actionpack/lib/action_dispatch/http/mime_negotiation.rb', line 86

def variant=(variant)
  variant = Array(variant)

  if variant.all? { |v| v.is_a?(Symbol) }
    @variant = ActiveSupport::ArrayInquirer.new(variant)
  else
    raise ArgumentError, "request.variant must be set to a Symbol or an Array of Symbols."
  end
end