Module Hirb::View

  1. lib/hirb/view.rb

This class is responsible for managing all view-related functionality.

Create a View

Let’s create a simple view for Hash objects: 

$ irb -rubygems
>> require 'hirb'
=>true
>> Hirb.enable
=>nil
>> require 'yaml'
=>true

# A view method is the smallest view
>> def yaml(output); output.to_yaml; end
=> nil
# Add the view
>> Hirb.add_view Hash, :method=>:yaml
=> true

# Hashes now appear as yaml
>> {:a=>1, :b=>{:c=>3}}
---
:a : 1
:b :
  :c : 3
=> true

Another way of creating a view is a Helper class: 

# Create yaml view class
>> class Hirb::Helpers::Yaml; def self.render(output, options={}); output.to_yaml; end ;end
=>nil
# Add the view
>> Hirb.add_view Hash, :class=>Hirb::Helpers::Yaml
=>true

# Hashes appear as yaml like above ...

Configure a View

To configure the above Helper class as a view, either pass Hirb.enable a hash: 

# In .irbrc
require 'hirb'
# View class needs to come before enable()
class Hirb::Helpers::Yaml; def self.render(output, options={}); output.to_yaml; end ;end
Hirb.enable :output=>{"Hash"=>{:class=>"Hirb::Helpers::Yaml"}}

Or create a config file at config/hirb.yml or ~/.hirb.yml: 

# The config file for the yaml example would look like:
# ---
# :output :
#   Hash :
#    :class : Hirb::Helpers::Yaml

# In .irbrc
require 'hirb'
# View class needs to come before enable()
class Hirb::Helpers::Yaml; def self.render(output, options={}); output.to_yaml; end ;end
Hirb.enable

For more about configuring Hirb, see the Config Files section in Hirb.

Constants

DEFAULT_WIDTH = 120
DEFAULT_HEIGHT = 40

Attributes

config [R]
render_method [RW]

Public class methods

add (klass, view_config)

Adds a view when View is enabled. See Formatter.add_view for more details.

[show source] 
# File lib/hirb/view.rb, line 166
      def add(klass, view_config)
        if enabled?
          formatter.add_view(klass, view_config)
        else
          puts "View must be enabled to add a view"
        end
      end
capture_and_render (&block)

Captures STDOUT and renders it using render_method(). The main use case is to conditionally page captured stdout.

[show source] 
# File lib/hirb/view.rb, line 134
      def capture_and_render(&block)
        render_method.call Util.capture_stdout(&block)
      end
disable ()

Disable’s Hirb’s output and revert’s irb’s output method if irb exists.

[show source] 
# File lib/hirb/view.rb, line 98
      def disable
        @enabled = false
        unalias_output_method(@output_method) if @output_method
        false
      end
enable (options={}, &block)

This activates view functionality i.e. the formatter, pager and size detection. If irb exists, it overrides irb’s output method with Hirb::View.view_output. When called multiple times, new configs are merged into the existing config. If using Wirble, you should call this after it. The view configuration can be specified in a hash via a config file, or as options to this method. In addition to the config keys mentioned in Hirb, options also take the following keys:

Options:

  • config_file: Name of config file(s) that are merged into existing config
  • output_method: Specify an object’s class and instance method (separated by a period) to be realiased with hirb’s view system. The instance method should take a string to be output. Default is IRB::Irb.output_value if using irb.

Examples: 

Hirb.enable
Hirb.enable :formatter=>false, :output_method=>"Mini.output"
[show source] 
# File lib/hirb/view.rb, line 81
      def enable(options={}, &block)
        Array(options.delete(:config_file)).each {|e|
          @new_config_file = true
          Hirb.config_files << e
        }
        enable_output_method(options.delete(:output_method))
        merge_or_load_config options
        resize(config[:width], config[:height])
        @enabled = true
      end
enabled? ()

Indicates if Hirb::View is enabled.

[show source] 
# File lib/hirb/view.rb, line 93
      def enabled?
        @enabled || false
      end
formatter_config ()

Current formatter config, storing a hash of all static views

[show source] 
# File lib/hirb/view.rb, line 161
      def formatter_config
        formatter.config
      end
height ()

Current console height

[show source] 
# File lib/hirb/view.rb, line 156
      def height
        config ? config[:height] : DEFAULT_HEIGHT
      end
render_method ()

A lambda or proc which handles the final formatted object. Although this pages/puts the object by default, it could be set to do other things i.e. write the formatted object to a file.

[show source] 
# File lib/hirb/view.rb, line 141
      def render_method
        @render_method ||= default_render_method
      end
reset_render_method ()

Resets render_method back to its default.

[show source] 
# File lib/hirb/view.rb, line 146
      def reset_render_method
        @render_method = default_render_method
      end
resize (width=nil, height=nil)

Resizes the console width and height for use with the table and pager i.e. after having resized the console window. *nix users should only have to call this method. Non-*nix users should call this method with explicit width and height. If you don’t know your width and height, in irb play with “a”* width to find width and puts “an“ * height to find height.

[show source] 
# File lib/hirb/view.rb, line 117
      def resize(width=nil, height=nil)
        config[:width], config[:height] = determine_terminal_size(width, height)
        pager.resize(config[:width], config[:height])
      end
toggle_formatter ()

Toggles formatter on or off.

[show source] 
# File lib/hirb/view.rb, line 110
      def toggle_formatter
        config[:formatter] = !config[:formatter]
      end
toggle_pager ()

Toggles pager on or off. The pager only works while Hirb::View is enabled.

[show source] 
# File lib/hirb/view.rb, line 105
      def toggle_pager
        config[:pager] = !config[:pager]
      end
view_output (output, options={})

This is the main method of this class. When view is enabled, this method searches for a formatter it can use for the output and if successful renders it using render_method(). The options this method takes are helper config hashes as described in Hirb::Formatter.format_output(). Returns true if successful and false if no formatting is done or if not enabled.

[show source] 
# File lib/hirb/view.rb, line 125
      def view_output(output, options={})
        enabled? && config[:formatter] && render_output(output, options)
      rescue Exception=>e
        index = (obj = e.backtrace.find {|f| f =~ /^\(eval\)/}) ? e.backtrace.index(obj) : e.backtrace.length
        $stderr.puts "Hirb Error: #{e.message}", e.backtrace.slice(0,index).map {|e| "    " + e }
        true
      end
width ()

Current console width

[show source] 
# File lib/hirb/view.rb, line 151
      def width
        config ? config[:width] : DEFAULT_WIDTH
      end