Class: HelpfulERB

Inherits:
Object show all
Defined in:
lib/helpful_erb.rb

Defined Under Namespace

Classes: Error

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(text, filename = nil, opts = {}) ⇒ HelpfulERB

Returns a new instance of HelpfulERB.



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# File 'lib/helpful_erb.rb', line 17

def initialize(text, filename=nil, opts={})
  @text = text
  @filename = filename
  @lines_before = opts[:before] || 5
  @lines_after = opts[:before] || 1

  @erb = ::ERB.new(@text, nil, '-')
  @erb.filename = @filename if @filename
end

Instance Attribute Details

#erb ⇒ Object

ERB object



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# File 'lib/helpful_erb.rb', line 8

def erb
  @erb
end

#filename ⇒ Object

Template filename



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# File 'lib/helpful_erb.rb', line 15

def filename
  @filename
end

#lines_after ⇒ Object

Returns the value of attribute lines_after.



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# File 'lib/helpful_erb.rb', line 12

def lines_after
  @lines_after
end

#lines_before ⇒ Object

Returns the value of attribute lines_before.



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# File 'lib/helpful_erb.rb', line 10

def lines_before
  @lines_before
end

Instance Method Details

#result(binder = nil) ⇒ Object 



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# File 'lib/helpful_erb.rb', line 27

def result(binder=nil)
  begin
    return @erb.result(binder)
  rescue Exception => e
    stack = caller 0
    for i in 0..e.backtrace.size
      l = e.backtrace[i]
      #puts "%s %s" % [i, l];
      break if l =~ /^([^:]+):(\d+):in `(render|result)'$/
    end
    template = $1
    line_number = $2.to_i
    raise Exception.new("Caught ERB error but couldn't find line number in backtrace:\n#{e.backtrace.join("\n")}") unless line_number

    lines = @text.split(/\n/)

    min = line_number - @lines_before
    min = 0 if min < 0

    max = line_number + @lines_after
    max = lines.size if max > lines.size

    width = max.to_s.size

    msg = "Problem with template '#{template}' at line #{line_number}:\n"
    for i in min..max
      n = i+1
      marker = n == line_number ? "*" : ""
      msg << "\n%2s %#{width}i %s" % [marker, n, lines[i]]
    end
    msg << "\n\n(#{e.exception.class}) #{e.message}"


    raise NestedError.new(msg, e)
  end
end