snippetsmania.com
Post and share your code snippets

# lib/widgets/widget.rb
# Superclass for our form element "widgets"
class Widget
include Merb::GlobalHelpers

# This is necessary to include Merb::GlobalHelpers
class_inheritable_accessor :_default_builder

# These are for convenience
attr_accessor :params
attr_accessor :session

def initialize(params = {}, session = {})
self.params = params
self.session = session
end

def value
end
end

# lib/widgets/weight_input_switcher.rb
class WeightInputSwitcher < Widget
attr_accessor :attribute_name, :weight_in_kg, :unit_preference

# View methods
def setup(attribute_name, weight_in_kg = nil, unit_preference = session[:unit_preference])
self.attribute_name = attribute_name
self.weight_in_kg = weight_in_kg
self.unit_preference = unit_preference
self
end

def switcher
html = "<div class='weight_input_switcher'>"
html += weight_input("lbs")
html += weight_input("kg")
html += weight_input("st")
html += "</div>"
html
end

def weight_input
html = "<span class='weight_input #{unit_preference}'>"
html += weight_input_field
html += "</span>"
end

def weight_input_field
if unit_preference == "st"
stone, lbs = if weight_in_kg.to_i == 0
["",""]
else
weight_input_value(weight_in_kg, unit_preference).split(" st ")
end

html = text_field attribute_name, :value => stone, :name => "weight_input[stone]", :class => "weight_input_field stone"
html += "<span class='weight_unit'>stone</span>"
html += text_field attribute_name, :value => lbs, :name => "weight_input[lbs]", :class => "weight_input_field stone lbs"
html += "<span class='weight_unit'>lbs</span>"
else
value = weight_input_value(weight_in_kg, unit_preference)

html = text_field attribute_name, :value => value, :name => "weight_input", :class => "weight_input_field"
html += "<span class='weight_unit'>" + unit_preference.to_s + "</span>"
end
html
end

# Parse methods
# We kinda cheat here and use params. Need to figure out a better way to do this.
def value
if params["weight_input"]["stone"]
"#{params["weight_input"]["stone"]} st #{params["weight_input"]["lbs"]} lbs"
else
"#{params["weight_input"]} #{Units.weight_full_to_abbreviation_map[unit_preference]}"
end
end

private
def weight_input_value(weight_in_kg, unit_preference)
begin
weight_in_kg.to_display_weight_without_unit(unit_preference)
rescue
""
end
end
end

# The following is added to global_helpers.rb
def widget(klass, *args)
klass.new(params, session).setup(*args)
end

# An example of using the "Widget" to display form elements
widget(WeightInputSwitcher, :weight, @current_user.current_weight).switcher

# An example of using the "Widget" to get the value of form elements
weight_widget = widget(WeightInputSwitcher, :weight, 0, "", user[:unit_preference])
weight = weight_widget.value

source