Class: Utopia::Redirection::Errors

Inherits:
Protocol::HTTP::Middleware
  • Object
show all
Defined in:
lib/utopia/redirection/errors.rb

Overview

A middleware which performs internal redirects based on error status codes.

Place this middleware after client-visible redirection middleware in the application configuration. Internal error-document requests invoke the delegate directly, bypassing middleware configured before this one.

Instance Method Summary collapse

Constructor Details

#initialize(app, codes = {}) ⇒ Errors

Returns a new instance of Errors.

Parameters:

  • codes (Hash<Integer,String>) (defaults to: {}) —

    The redirection path for a given error code.



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# File 'lib/utopia/redirection/errors.rb', line 20

def initialize(app, codes = {})
	super(app)
	
	@codes = codes
end

Instance Method Details

#call(request) ⇒ Object

Replace an unhandled error response with its configured error document.



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# File 'lib/utopia/redirection/errors.rb', line 47

def call(request)
	response = Response.wrap(@delegate.call(request))
	
	if unhandled_error?(response) && location = @codes[response.status]
		resource_status = response.status
		
		# The original response is replaced by the configured error document:
		response.close
		
		error_request = request.with(method: "GET", path: location)
		
		error_response = Response.wrap(@delegate.call(error_request))
		
		if error_response.status >= 400
			error = RequestFailure.new(request.url.path.encoded, resource_status, location, error_response.status)
			
			# The failed error document will not be returned to the server:
			error_response.close(error)
			
			raise error
		else
			# Feed the error code back with the error document:
			error_response.status = resource_status
			return error_response
		end
	else
		return response
	end
end

#freeze ⇒ Object

Freeze this object and its internal state.



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# File 'lib/utopia/redirection/errors.rb', line 28

def freeze
	return self if frozen?
	
	@codes.freeze
	
	super
end

#unhandled_error?(response) ⇒ Boolean

Check whether the response status requires error handling.

Returns:

  • (Boolean) 


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# File 'lib/utopia/redirection/errors.rb', line 39

def unhandled_error?(response)
	response.status >= 400 && response.headers.empty?
end