Exception: StandardError

Inherits:
Exception
  • Object
show all
Defined in:
lib/maveric/extensions.rb

Overview

Extensions to StandardError to enable their usage in Maveric as responses.

Constant Summary collapse

DEFAULT_STATUS = 
500
DEFAULT_HEADERS = 
{'Content-Type'=>'text/plain'}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data = nil) ⇒ StandardError

After a bit of experimenting with Exception and raise I determinee a fun and simple way to generate fast HTTP response error thingies. As long as you’re within a call to dispatch (with no further rescue clauses) the StandardError will propogate up and be returned. As a StandardError has similar accessors as a Controller, they should be compatible with any outputting implimentation.

raise StandardErrpr; # 500 error
raise StandardError, 'Crap!'; # 500 error with message set to 'Crap!'
raise StandardError, [status, headers, body, *other_data] # Magic!

In the final example line an Array is passed to raise as a second argument rather than a String. This is taken as the HTTP status code. The next element is tested to be a Hash, if so then it’s values are merged into the HTTP headers. Then next item is tested to be a String, if so it is appended to the response body. All remaining elements are appended to the response body in inspect format.

A simple way of only including data that might be interpreted to being the status, headers, or body is to place a nil previous to the data you want apended to the response body.



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# File 'lib/maveric/extensions.rb', line 77

def initialize data=nil
  #consider autosettign @status, like 503 for NoMethodError
  if data.is_a? Array and data[0].is_a? Integer
    @body = ''
    @status = data.shift if Integer === data.first
    @headers = DEF_HEADERS.merge data.shift if Hash === data.first
    @body << data.shift if String === data.first
    msg = @body.dup
    @body << "\n\n#{data.compact.map{|e|e.inspect}*"\n"}" unless data.empty?
    data = msg
  end
  old_init data
end

Instance Attribute Details

#body ⇒ Object

Unless @body is defined, a self inspect and backtrace is output.



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# File 'lib/maveric/extensions.rb', line 47

def body; @body or [inspect, *backtrace]*"\n"; end

#headers ⇒ Object 



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# File 'lib/maveric/extensions.rb', line 45

def headers; @headers or DEFAULT_HEADERS; end

#status ⇒ Object 



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# File 'lib/maveric/extensions.rb', line 44

def status; @status or DEFAULT_STATUS; end

Instance Method Details

#old_init ⇒ Object 



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# File 'lib/maveric/extensions.rb', line 54

alias_method :old_init, :initialize

#to_http ⇒ Object

See ::Maveric::Controller#to_http



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# File 'lib/maveric/extensions.rb', line 49

def to_http
  response = "Status: #{status}"+::Maveric::EOL
  response << headers.map{|(k,v)| "#{k}: #{v}" }*::Maveric::EOL
  response << ::Maveric::EOL*2 + body
end