Class: Renderer

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

Overview

Renderer is the base class for all text renderer plugins

It defines methods for rendering data which will be called from the specialized content methods in the subclasses.

Subclasses can define the output for the ‘show` and `compare` commands using the following `content` methods:

For ‘machinery show`:

content

(required) Defines the output for a scope in ‘machinery show`

For ‘machinery compare`:

compare_content_only_in

Defines the output of the “only in x” sections. The default behavior is to fall back to ‘content`.

compare_content_common

Defines the output of the “in both” section. The default behavior is to fall back to ‘content`.

compare_content_changed

Defines the output of the “in both with changed attributes” section for scopes where this is supported.

The names of the subclasses are 1:1 mappings of the scope areas, e.g. the PackagesRenderer class would be used for rendering when the user specifies “–scope=packages”.

The rendering methods are: def heading(s) - Render a heading def puts(s) - Print one line def list(name) - Start a list. This method takes a block where the items are

created.

def item(s) - Print a list item

Accordingly a simple renderer for the “packages” scope could look like this:

class PackagesRenderer < Renderer

def content(description)
  return if description.packages.empty?

  list "Packages" do
    description.packages.each do |p|
      item "#{p.name} (#{p.version})"
    end
  end
end

end

Defined Under Namespace

Classes: InvalidStructureError

Constant Summary collapse

@@renderers = 
[]

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#buffer ⇒ Object

Returns the value of attribute buffer.



67
68
69
 
# File 'lib/renderer.rb', line 67

def buffer
  @buffer
end

#system_description ⇒ Object

Returns the value of attribute system_description.



66
67
68
 
# File 'lib/renderer.rb', line 66

def system_description
  @system_description
end

Class Method Details

.all ⇒ Object 



79
80
81
 
# File 'lib/renderer.rb', line 79

def all
  @@renderers.map { |renderer| renderer.new }
end

.for(scope) ⇒ Object 



83
84
85
86
87
88
89
 
# File 'lib/renderer.rb', line 83

def for(scope)
  class_name = "#{scope.split("_").map(&:capitalize).join}Renderer"

  if Object.const_defined?(class_name)
    Object.const_get(class_name).new
  end
end

.inherited(klass) ⇒ Object 



75
76
77
 
# File 'lib/renderer.rb', line 75

def inherited(klass)
  @@renderers << klass
end

Instance Method Details

#compare_content_common(description) ⇒ Object 



175
176
177
 
# File 'lib/renderer.rb', line 175

def compare_content_common(description)
  content(description)
end

#compare_content_only_in(description) ⇒ Object 



171
172
173
 
# File 'lib/renderer.rb', line 171

def compare_content_only_in(description)
  content(description)
end

#render(system_description, options = {}) ⇒ Object

Renders one system description using the specialized ‘content` method



100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
 
# File 'lib/renderer.rb', line 100

def render(system_description, options = {})
  @options = options
  @buffer = ""
  @indent = 2
  @stack = []

  if system_description[scope]
    header = display_name
    meta = system_description[scope].meta

    if meta
        header += " [#{meta.hostname}]"
        date = Time.parse(meta.modified).localtime
        date_human = date.strftime "%Y-%m-%d %H:%M:%S"
        header += " (#{date_human})"
    end

    heading(header)
  end

  content(system_description)

  @buffer += "\n" unless @buffer.empty? || @buffer.end_with?("\n\n")

  @buffer
end

#render_comparison(comparison, options = {}) ⇒ Object

Renders the result of a comparison of two system descriptions.



128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
 
# File 'lib/renderer.rb', line 128

def render_comparison(comparison, options = {})
  @options = options
  @buffer = ""
  @indent = 0
  @stack = []

  show_heading = if options[:show_all]
    comparison.only_in1 || comparison.only_in2 || comparison.changed || comparison.common
  else
    comparison.only_in1 || comparison.only_in2 || comparison.changed
  end

  heading(display_name) if show_heading

  render_comparison_only_in(comparison.as_description(:one))
  render_comparison_only_in(comparison.as_description(:two))
  render_comparison_changed(comparison) if comparison.changed
  render_comparison_common(comparison.as_description(:common)) if @options[:show_all]
  @buffer
end

#render_comparison_changed(comparison) ⇒ Object 



157
158
159
160
161
 
# File 'lib/renderer.rb', line 157

def render_comparison_changed(comparison)
  puts "In both with different attributes ('#{comparison.name1}' <> '#{comparison.name2}'):"
  indent { compare_content_changed(comparison.changed) }
  @buffer += "\n" unless @buffer.empty? || @buffer.end_with?("\n\n")
end

#render_comparison_common(description) ⇒ Object 



163
164
165
166
167
168
169
 
# File 'lib/renderer.rb', line 163

def render_comparison_common(description)
  return if !description[scope]

  puts "Common to both systems:"
  indent { compare_content_common(description) }
  @buffer += "\n" unless @buffer.empty? || @buffer.end_with?("\n\n")
end

#render_comparison_missing_scope(description1, description2) ⇒ Object 



179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
 
# File 'lib/renderer.rb', line 179

def render_comparison_missing_scope(description1, description2)
  @buffer = ""
  @indent = 0
  @stack = []
  missing_descriptions = Array.new

  if !description1[scope]
    missing_descriptions << description1.name
  end
  if !description2[scope]
    missing_descriptions << description2.name
  end

  if missing_descriptions.count == 1
    @buffer += "# #{display_name}\n"
    indent { puts "Unable to compare, no data in '#{missing_descriptions.join("', '")}'" }
  end
  @buffer += "\n" unless @buffer.empty? || @buffer.end_with?("\n\n")

  @buffer
end

#render_comparison_only_in(description) ⇒ Object 



149
150
151
152
153
154
155
 
# File 'lib/renderer.rb', line 149

def render_comparison_only_in(description)
  return if !description[scope]

  puts "Only in '#{description.name}':"
  indent { compare_content_only_in(description) }
  @buffer += "\n" unless @buffer.empty? || @buffer.end_with?("\n\n")
end

#scope ⇒ Object 



92
93
94
95
96
97
 
# File 'lib/renderer.rb', line 92

def scope
  # Return the un-camelcased name of the inspector,
  # e.g. "foo_bar" for "FooBarInspector"
  scope = self.class.name.match(/^(.*)Renderer$/)[1]
  scope.gsub(/([^A-Z])([A-Z])/, "\\1_\\2").downcase
end