Exception: ActionView::TemplateError

Inherits:
ActionViewError show all
Defined in:
lib/action_view/template_error.rb

Overview

The TemplateError exception is raised when the compilation of the template fails. This exception then gathers a bunch of intimate details and uses it to report a very precise exception message.

Constant Summary collapse

SOURCE_CODE_RADIUS =

:nodoc:

3

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(template, assigns, original_exception) ⇒ TemplateError

Returns a new instance of TemplateError.



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# File 'lib/action_view/template_error.rb', line 9

def initialize(template, assigns, original_exception)
  @template, @assigns, @original_exception = template, assigns.dup, original_exception
  @backtrace = compute_backtrace
end

Instance Attribute Details

#original_exceptionObject (readonly)

Returns the value of attribute original_exception.



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# File 'lib/action_view/template_error.rb', line 7

def original_exception
  @original_exception
end

Instance Method Details

#backtraceObject

don’t do anything nontrivial here. Any raised exception from here becomes fatal (and can’t be rescued).



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# File 'lib/action_view/template_error.rb', line 79

def backtrace
  @backtrace
end

#clean_backtraceObject



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# File 'lib/action_view/template_error.rb', line 22

def clean_backtrace
  if defined?(Rails) && Rails.respond_to?(:backtrace_cleaner)
    Rails.backtrace_cleaner.clean(original_exception.backtrace)
  else
    original_exception.backtrace
  end
end

#file_nameObject



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# File 'lib/action_view/template_error.rb', line 14

def file_name
  @template.relative_path
end

#line_numberObject



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# File 'lib/action_view/template_error.rb', line 63

def line_number
  @line_number ||=
    if file_name
      regexp = /#{Regexp.escape File.basename(file_name)}:(\d+)/

      $1 if message =~ regexp or clean_backtrace.find { |line| line =~ regexp }
    end
end

#messageObject



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# File 'lib/action_view/template_error.rb', line 18

def message
  ActiveSupport::Deprecation.silence { original_exception.message }
end

#source_extract(indentation = 0) ⇒ Object



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# File 'lib/action_view/template_error.rb', line 39

def source_extract(indentation = 0)
  return unless num = line_number
  num = num.to_i

  source_code = @template.source.split("\n")

  start_on_line = [ num - SOURCE_CODE_RADIUS - 1, 0 ].max
  end_on_line   = [ num + SOURCE_CODE_RADIUS - 1, source_code.length].min

  indent = ' ' * indentation
  line_counter = start_on_line
  return unless source_code = source_code[start_on_line..end_on_line]

  source_code.sum do |line|
    line_counter += 1
    "#{indent}#{line_counter}: #{line}\n"
  end
end

#sub_template_messageObject



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# File 'lib/action_view/template_error.rb', line 30

def sub_template_message
  if @sub_templates
    "Trace of template inclusion: " +
    @sub_templates.collect { |template| template.relative_path }.join(", ")
  else
    ""
  end
end

#sub_template_of(template_path) ⇒ Object



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# File 'lib/action_view/template_error.rb', line 58

def sub_template_of(template_path)
  @sub_templates ||= []
  @sub_templates << template_path
end

#to_sObject



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# File 'lib/action_view/template_error.rb', line 72

def to_s
  "\n#{self.class} (#{message}) #{source_location}:\n" + 
  "#{source_extract}\n    #{clean_backtrace.join("\n    ")}\n\n"
end