Exception: Exception

Defined in:
lib/nitro/compiler/errors.rb

Overview

This supports source code extraction from a full backtrace from any exception and also exposes class methods incase you wish to harness them from elsewhere. – TODO: Cache source code? Memory vs Speed - Is it worth it? FIXME: Don’t change the Exception class, use NitroException or something. ++

Direct Known Subclasses

Nitro::ActionExit, Nitro::RenderExit

Constant Summary collapse

SOURCE_RADIUS =

Radius of the source code to display arround the error line.

5

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.file_and_line_no(step) ⇒ Object

Extracts the filename and line from the given line (step) of the backtrace.



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# File 'lib/nitro/compiler/errors.rb', line 24

def file_and_line_no(step)
  file = no = nil
  if res = step.match(/^(.+):(\d+)$/)
    file = res[1]
    no = res[2]
  elsif res = step.match(/^(.+):(\d+):in `.+'$/)
    file = res[1]
    no = res[2]
  end
  if file and no
    [file,no.to_i]
  else
    nil
  end
end

.source_extract(step, indent = 0) ⇒ Object

Extract the source arround the error line.



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# File 'lib/nitro/compiler/errors.rb', line 42

def source_extract(step, indent = 0)
  begin
    file, no = file_and_line_no(step)        
    source = File.read(file)

    if file =~ /\.xhtml$/
      source = Compiler.new(Nitro::Controller).transform_template(:action, source)
      no -= 2
    end

    source = source.split("\n")
    start = (no-1) - SOURCE_RADIUS
    finish = (no-1) + SOURCE_RADIUS
    start = 0 if start < 0
    finish = source.size if finish > source.size
  
    number = start
    extract = source[start..finish].collect do |line| 
      number += 1
      line = line.gsub(/; @out #{Nitro::TemplateMixin::START_DELIM}/, ' ?>').gsub(/#{Nitro::TemplateMixin::END_DELIM}/, '<?r ')
      "#{' ' * indent}#{number}: #{line}"
    end  

    return extract.join("\n")
  rescue Object => ex
    ''
  end
end

Instance Method Details

#file_and_line_no(step) ⇒ Object 



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# File 'lib/nitro/compiler/errors.rb', line 96

def file_and_line_no(step)
  self.class.file_and_line_no(step)
end

#hot_file ⇒ Object

Returns the ‘hot’ backtrace file.



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# File 'lib/nitro/compiler/errors.rb', line 92

def hot_file
  file_and_line_no(hot_trace_step).first
end

#hot_trace_index ⇒ Object

Identifies the ‘hot’ index in the backtrace, where the error actually happened.



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# File 'lib/nitro/compiler/errors.rb', line 76

def hot_trace_index
  index = 0
  while backtrace[index] =~ /controller\.rb(.*)method_missing/ 
    index += 1
  end
  return index
end

#hot_trace_step ⇒ Object

Returns the ‘hot’ backtrace line.



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# File 'lib/nitro/compiler/errors.rb', line 86

def hot_trace_step
  backtrace[hot_trace_index]
end

#source_extract(step = hot_trace_step, indent = 0) ⇒ Object 



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# File 'lib/nitro/compiler/errors.rb', line 100

def source_extract(step = hot_trace_step, indent = 0)
  self.class.source_extract(step,indent)
end

#source_for_backtrace(indent = 0) ⇒ Object

Extract source for backtrace.



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# File 'lib/nitro/compiler/errors.rb', line 106

def source_for_backtrace(indent = 0)
  backtrace.inject([]) do |sources, step| 
    sources << source_extract(step, indent)
  end
end