Chapter 5 example

gistfile1.coffee

class Server
  @http = (method, src, callback) ->
    handler = ->
      if @readyState is 4 and @status is 200
        unless @responseText is null
          callback JSON.parse @responseText

    client = new XMLHttpRequest
    client.onreadystatechange = handler
    client.open method, src
    client.send()

  @get = (src, callback) ->
    http "GET", src, callback

  @post = (src, callback) ->
    http "POST", src, callback

class Mixin
  @:: = null
  constructor: (to) ->
    for key, val of @
      to[key] = val

class View extends Mixin
  constructor: (to) ->
    super
    @node = document.createElement 'div'
    @node.className = "product"
    document.body.appendChild @node
  template = (fn) ->
    @template = fn
  handler: (event, fn) ->
    @node[event] = fn()
  update: ->
    @node.innerHTML = @template()

class Product
  products = []
  @find = (query) ->
    (product for product in products when product.name is query)
  constructor: (@name, @info) ->
    products.push @
    @view = new View @
    @view.template = =>
      display_info = "<div>#{key}: #{val}</div>" for own key, val of @info
      "#{@name} #{display_info}"
    @view.render()
    @view.handler "onclick", @purchase
  purchase: =>
    if @info.stock > 0
      Server.post "/json/purchase/#{@purchase_category}/#{@name}", (res) =>
        if res.status is "success"
          @info = res.update
          @view.render()

class Camera extends Product
  purchase_category: 'camera'
  megapixels: -> @info.megapixels || "Unknown"


class Skateboard extends Product
  purchase_category: 'skateboard'
  length: -> @info.length || "Unknown"


class Shop
  constructor: ->
    @view = document.createElement "input"
    @view.type = "text"
    @view.value = ""
    @view.onchange = ->
      console.log Product.find @value
    document.body.appendChild @view
    Server.get '/json/list', (data) ->
      for own category of data
        for own name, info of data[category]
          switch category
            when 'camera'
              new Camera name, info
            when 'skateboard'
              new Skateboard name, info


shop = new Shop