Class: Chef::Knife::Core::GenericPresenter

Inherits:
Object
  • Object
show all
Defined in:
lib/chef/knife/core/generic_presenter.rb

Overview

The base presenter class for displaying structured data in knife commands. This is not an abstract base class, and it is suitable for displaying most kinds of objects that knife needs to display.

Direct Known Subclasses

NodePresenter, StatusPresenter

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ui, config) ⇒ GenericPresenter

Instaniates a new GenericPresenter. This is generally handled by the Chef::Knife::UI object, though you need to match the signature of this method if you intend to use your own presenter instead.



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# File 'lib/chef/knife/core/generic_presenter.rb', line 59

def initialize(ui, config)
  @ui, @config = ui, config
end

Instance Attribute Details

#config ⇒ Object (readonly)

Returns the value of attribute config.



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# File 'lib/chef/knife/core/generic_presenter.rb', line 54

def config
  @config
end

#ui ⇒ Object (readonly)

Returns the value of attribute ui.



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# File 'lib/chef/knife/core/generic_presenter.rb', line 53

def ui
  @ui
end

Instance Method Details

#attribute_field_separator ⇒ Object

GenericPresenter is used in contexts where MultiAttributeReturnOption is not, so we need to set the default value here rather than as part of the CLI option.



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# File 'lib/chef/knife/core/generic_presenter.rb', line 185

def attribute_field_separator
  config[:field_separator] || "."
end

#extract_nested_value(data, nested_value_spec) ⇒ Object 



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# File 'lib/chef/knife/core/generic_presenter.rb', line 189

def extract_nested_value(data, nested_value_spec)
  nested_value_spec.split(attribute_field_separator).each do |attr|
    data =
      if data.is_a?(Array)
        data[attr.to_i]
      elsif data.respond_to?(:[], false) && data.respond_to?(:key?) && data.key?(attr)
        data[attr]
      elsif data.respond_to?(attr.to_sym, false)
        # handles -a chef_environment and other things that hang of the node and aren't really attributes
        data.public_send(attr.to_sym)
      else
        nil
      end
  end
  # necessary (?) for coercing objects (the run_list object?) to hashes
  ( !data.is_a?(Array) && data.respond_to?(:to_hash) ) ? data.to_hash : data
end

#format(data) ⇒ Object

Returns a String representation of data that is suitable for output to a terminal or perhaps for data interchange with another program. The representation of the data depends on the value of the ‘config` setting.



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# File 'lib/chef/knife/core/generic_presenter.rb', line 80

def format(data)
  case parse_format_option
  when :summary
    summarize(data)
  when :text
    text_format(data)
  when :json
    Chef::JSONCompat.to_json_pretty(data)
  when :yaml
    require "yaml"
    YAML.dump(data)
  when :pp
    require "stringio" unless defined?(StringIO)
    # If you were looking for some attribute and there is only one match
    # just dump the attribute value
    if config[:attribute] && data.length == 1
      data.values[0]
    else
      out = StringIO.new
      PP.pp(data, out)
      out.string
    end
  end
end

#format_cookbook_list_for_display(item) ⇒ Object 



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# File 'lib/chef/knife/core/generic_presenter.rb', line 207

def format_cookbook_list_for_display(item)
  if config[:with_uri]
    item.inject({}) do |collected, (cookbook, versions)|
      collected[cookbook] = {}
      versions["versions"].each do |ver|
        collected[cookbook][ver["version"]] = ver["url"]
      end
      collected
    end
  else
    versions_by_cookbook = item.inject({}) do |collected, ( cookbook, versions )|
      collected[cookbook] = versions["versions"].map { |v| v["version"] }
      collected
    end
    key_length = versions_by_cookbook.empty? ? 0 : versions_by_cookbook.keys.map(&:size).max + 2
    versions_by_cookbook.sort.map do |cookbook, versions|
      "#{cookbook.ljust(key_length)} #{versions.join("  ")}"
    end
  end
end

#format_data_subset_for_display(data) ⇒ Object 



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# File 'lib/chef/knife/core/generic_presenter.rb', line 157

def format_data_subset_for_display(data)
  subset = if config[:attribute]
             result = {}
             Array(config[:attribute]).each do |nested_value_spec|
               nested_value = extract_nested_value(data, nested_value_spec)
               result[nested_value_spec] = nested_value
             end
             result
           elsif config[:run_list]
             run_list = data.run_list.run_list
             { "run_list" => run_list }
           else
             raise ArgumentError, "format_data_subset_for_display requires attribute, run_list, or id_only config option to be set"
           end
  { name_or_id_for(data) => subset }
end

#format_for_display(data) ⇒ Object 



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# File 'lib/chef/knife/core/generic_presenter.rb', line 145

def format_for_display(data)
  if formatting_subset_of_data?
    format_data_subset_for_display(data)
  elsif config[:id_only]
    name_or_id_for(data)
  elsif config[:environment] && data.respond_to?(:chef_environment)
    { "chef_environment" => data.chef_environment }
  else
    data
  end
end

#format_list_for_display(list) ⇒ Object 



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# File 'lib/chef/knife/core/generic_presenter.rb', line 141

def format_list_for_display(list)
  config[:with_uri] ? list : list.keys.sort { |a, b| a <=> b }
end

#formatting_subset_of_data? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chef/knife/core/generic_presenter.rb', line 178

def formatting_subset_of_data?
  config[:attribute] || config[:run_list]
end

#interchange? ⇒ Boolean

Is the selected output format a data interchange format? Returns true if the selected output format is json or yaml, false otherwise. Knife search uses this to adjust its data output so as not to produce invalid JSON output.

Returns:

  • (Boolean) 


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# File 'lib/chef/knife/core/generic_presenter.rb', line 67

def interchange?
  case parse_format_option
  when :json, :yaml
    true
  else
    false
  end
end

#name_or_id_for(data) ⇒ Object 



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# File 'lib/chef/knife/core/generic_presenter.rb', line 174

def name_or_id_for(data)
  data.respond_to?(:name) ? data.name : data["id"]
end

#parse_format_option ⇒ Object

Converts the user-supplied value of ‘config` to a Symbol representing the desired output format.

Returns

returns one of :summary, :text, :json, :yaml, or :pp

Raises

Raises an ArgumentError if the desired output format could not be determined from the value of ‘config`



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# File 'lib/chef/knife/core/generic_presenter.rb', line 112

def parse_format_option
  case config[:format]
  when "summary", /^s/, nil
    :summary
  when "text", /^t/
    :text
  when "json", /^j/
    :json
  when "yaml", /^y/
    :yaml
  when "pp", /^p/
    :pp
  else
    raise ArgumentError, "Unknown output format #{config[:format]}"
  end
end

#summarize(data) ⇒ Object

Summarize the data. Defaults to text format output, which may not be very summary-like



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# File 'lib/chef/knife/core/generic_presenter.rb', line 131

def summarize(data)
  text_format(data)
end

#text_format(data) ⇒ Object

Converts the data to a String in the text format. Uses Chef::Knife::Core::TextFormatter



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# File 'lib/chef/knife/core/generic_presenter.rb', line 137

def text_format(data)
  TextFormatter.new(data, ui).formatted_data
end