Class: WavefrontDisplay::Base

Inherits:
Object
  • Object
show all
Includes:
WavefrontCli::Constants
Defined in:
lib/wavefront-cli/display/base.rb

Overview

Print human-friendly output. If a command requires a dedicated handler to format its output, define a method with the same name as that which fetches the data, in a WavefrontDisplay class, extending this one.

We provide long_output() and terse_output() methods to solve standard formatting problems. To use them, define a do_() method but rather than printing the output, have it call the method.

Constant Summary

Constants included from WavefrontCli::Constants

WavefrontCli::Constants::DEFAULT_OPTS, WavefrontCli::Constants::HUMAN_TIME_FORMAT, WavefrontCli::Constants::HUMAN_TIME_FORMAT_MS

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data, options = {}) ⇒ Base

Returns a new instance of Base.



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# File 'lib/wavefront-cli/display/base.rb', line 29

def initialize(data, options = {})
  @data = data
  @options = options
  @indent = 0
  @indent_step = options[:indent_step] || 2
  @hide_blank = options[:hide_blank] || true
end

Instance Attribute Details

#data ⇒ Object (readonly)

Returns the value of attribute data.



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# File 'lib/wavefront-cli/display/base.rb', line 17

def data
  @data
end

#hide_blank ⇒ Object (readonly)

Returns the value of attribute hide_blank.



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# File 'lib/wavefront-cli/display/base.rb', line 17

def hide_blank
  @hide_blank
end

#indent ⇒ Object (readonly)

Returns the value of attribute indent.



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# File 'lib/wavefront-cli/display/base.rb', line 17

def indent
  @indent
end

#indent_step ⇒ Object (readonly)

Returns the value of attribute indent_step.



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# File 'lib/wavefront-cli/display/base.rb', line 17

def indent_step
  @indent_step
end

#indent_str ⇒ Object (readonly)

Returns the value of attribute indent_str.



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# File 'lib/wavefront-cli/display/base.rb', line 17

def indent_str
  @indent_str
end

#kw ⇒ Object (readonly)

Returns the value of attribute kw.



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# File 'lib/wavefront-cli/display/base.rb', line 17

def kw
  @kw
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/wavefront-cli/display/base.rb', line 17

def options
  @options
end

Instance Method Details

#_two_columns(data, kw = nil, fields = nil) ⇒ Object

A recursive function which displays a key-value hash in two columns. The key column width is automatically calculated. Multiple-value ‘v’s are printed one per line. Hashes are nested.

Parameters:

  • data (Array) —

    and array of objects to display. Each object should be a hash.

  • indent (Integer) —

    how many characters to indent the current data.



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# File 'lib/wavefront-cli/display/base.rb', line 123

def _two_columns(data, kw = nil, fields = nil)
  [data].flatten.each do |row|
    row.keep_if { |k, _v| fields.include?(k) } unless fields.nil?
    kw = key_width(row) unless kw
    @kw = kw unless @kw
    set_indent(indent)

    row.each do |k, v|
      next if v.respond_to?(:empty?) && v.empty? && hide_blank

      if v.is_a?(String) && v.match(/<.*>/)
        v = v.gsub(%r{<\/?[^>]*>}, '').delete("\n")
      end

      if v.is_a?(Hash)
        print_line(k)
        @indent += indent_step
        @kw -= 2
        _two_columns([v], kw - indent_step)
      elsif v.is_a?(Array)
        print_array(k, v)
      else
        print_line(k, v)
      end
    end
    puts if indent.zero?
  end

  @indent -= indent_step if indent > 0
  @kw += 2
  set_indent(indent)
end

#do_delete ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 226

def do_delete
  puts "Deleted #{friendly_name} '#{options[:'<id>']}'."
end

#do_import ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 221

def do_import
  puts "Imported #{friendly_name}."
  long_output
end

#do_list ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 213

def do_list
  long_output
end

#do_list_brief ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 217

def do_list_brief
  terse_output
end

#do_tag_add ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 234

def do_tag_add
  puts "Tagged #{friendly_name} '#{options[:'<id>']}'."
end

#do_tag_clear ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 242

def do_tag_clear
  puts "Cleared tags on #{friendly_name} '#{options[:'<id>']}'."
end

#do_tag_delete ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 238

def do_tag_delete
  puts "Deleted tag from #{friendly_name} '#{options[:'<id>']}'."
end

#do_tag_set ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 246

def do_tag_set
  puts "Set tags on #{friendly_name} '#{options[:'<id>']}'."
end

#do_tags ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 250

def do_tags
  if data.empty?
    puts "No tags set on #{friendly_name} '#{options[:'<id>']}'."
  else
    data.sort.each { |t| puts t }
  end
end

#do_undelete ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 230

def do_undelete
  puts "Undeleted #{friendly_name} '#{options[:'<id>']}'."
end

#drop_fields(*keys) ⇒ Object

Modify, in-place, the data structure to remove fields which we deem not of interest to the user.

Parameters:

  • keys (Symbol) —

    keys you do not wish to be shown.



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# File 'lib/wavefront-cli/display/base.rb', line 263

def drop_fields(*keys)
  data.delete_if { |k, _v| keys.include?(k.to_sym) }
end

#friendly_name ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 208

def friendly_name
  self.class.name.split('::').last.gsub(/([a-z])([A-Z])/, '\\1 \\2')
      .downcase
end

#human_time(t) ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 278

def human_time(t)
  str = t.to_s

  if str.length == 13
    fmt = '%Q'
    out_fmt = HUMAN_TIME_FORMAT_MS
  else
    fmt = '%s'
    out_fmt = HUMAN_TIME_FORMAT
  end

  DateTime.strptime(str, fmt).strftime(out_fmt)
end

#indent_wrap(line, cols = 78, offset = 22) ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 199

def indent_wrap(line, cols = 78, offset = 22)
  #
  # hanging indent long lines to fit in an 80-column terminal
  #
  return unless line
  line.gsub(/(.{1,#{cols - offset}})(\s+|\Z)/, "\\1\n#{' ' *
          offset}").rstrip
end

#key_width(hash, pad = 2) ⇒ Integer

Give it a key-value hash, and it will return the size of the first column to use when formatting that data.

Parameters:

  • hash (Hash) —

    the data for which you need a column width

  • pad (Integer) (defaults to: 2) —

    the number of spaces you want between columns

Returns:

  • (Integer) —

    length of longest key + pad



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# File 'lib/wavefront-cli/display/base.rb', line 194

def key_width(hash, pad = 2)
  return 0 if hash.keys.empty?
  hash.keys.map(&:size).max + pad
end

#long_output(fields = nil, modified_data = nil) ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 57

def long_output(fields = nil, modified_data = nil)
  _two_columns(modified_data || data, nil, fields)
end

#multicolumn(*keys) ⇒ Object

Print multiple column output. Currently this method does no word wrapping.

Parameters:

  • keys (Symbol) —

    the keys you want in the output. They will be printed in the order given.



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# File 'lib/wavefront-cli/display/base.rb', line 86

def multicolumn(*keys)
  len = Hash[*keys.map {|k| [k, 0]}.flatten]

  keys.each do |k|
    data.each do |obj|
      val = obj[k]
      val = val.join(', ') if val.is_a?(Array)
      len[k] = val.size if val.size > len[k]
    end
  end

  fmt = keys.each_with_object('') { |k, out| out.<< "%-#{len[k]}s  " }

  data.each do |obj|
    args = keys.map do |k|
      obj[k].is_a?(Array) ? obj[k].join(', ') : obj[k]
    end

    puts format(fmt, *args)
  end
end

#print_array(k, v) ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 156

def print_array(k, v)
  v.each_with_index do |w, i|
    if w.is_a?(Hash)
      print_line(k) if i.zero?
      @indent += indent_step
      @kw -= 2
      _two_columns([w], kw - indent_step)
      print_line('', '---') unless i == v.size - 1
    else
      if i.zero?
        print_line(k, v.shift)
      else
        print_line('', w)
      end
    end
  end
end

#print_line(key, value = '') ⇒ Object

Print a single line of output

Parameters:

  • key (String) —

    what to print in the first (key) column

  • val (String, Numeric) —

    what to print in the second column

  • indent (Integer) —

    number of leading spaces on line



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# File 'lib/wavefront-cli/display/base.rb', line 179

def print_line(key, value = '')
  if key.empty?
    puts ' ' * kw + value
  else
    puts indent_str + format("%-#{kw}s%s", key, value).fold(TW, kw)
  end
end

#readable_time(*keys) ⇒ Object

Modify, in-place, the data structure to make times human-readable. Automatically handles second and millisecond epoch times.



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# File 'lib/wavefront-cli/display/base.rb', line 271

def readable_time(*keys)
  keys.each do |k|
    next unless data.key?(k)
    data[k] = human_time(data[k])
  end
end

#run(method) ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 37

def run(method)
  if method == 'do_list'
    if options[:long]
      do_list
    else
      do_list_brief
    end

    return
  end

  if respond_to?("#{method}_brief")
    send("#{method}_brief")
  elsif respond_to?(method)
    send(method)
  else
    long_output
  end
end

#run_error(method) ⇒ Object

Display classes can provide a do_method_code() method, which handles <code> errors when running do_method()



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# File 'lib/wavefront-cli/display/base.rb', line 23

def run_error(method)
  return unless respond_to?(method)
  send(method)
  exit 1
end

#set_indent(indent) ⇒ Object 



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# File 'lib/wavefront-cli/display/base.rb', line 108

def set_indent(indent)
  @indent_str = ' ' * indent
end

#terse_output(col1 = :id, col2 = :name, modified_data = nil) ⇒ Nil

Extract two fields from a hash and print a list of them as pairs.

Parameters:

  • col1 (String) (defaults to: :id) —

    the field to use in the first column

  • col2 (String) (defaults to: :name) —

    the field to use in the second column

Returns:

  • (Nil) 


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# File 'lib/wavefront-cli/display/base.rb', line 68

def terse_output(col1 = :id, col2 = :name, modified_data = nil)
  d = modified_data || data
  want = d.each_with_object({}) { |r, a| a[r[col1]] = r[col2] }
  @indent_str = ''
  @kw = key_width(want)

  want.each do |k, v|
    v = v.join(', ') if v.is_a?(Array)
    print_line(k, v)
  end
end