First pass at Craigslist data model

Author: tannerwelsh

session-notes/2015-02-14/craigslist/Gemfile

@@ -0,0 +1,42 @@
+# 1. Define our objects and object relationships (no DB)
+# 2. Add some hard-coded dummy data
+# 3. Replace dummy data with database and DataMapper
+
+module Craigslist
+  ALL_POSTINGS = []
+
+  def self.all
+    ALL_POSTINGS
+  end
+
+  # bikes = Craigslist.bikes(make: 'Santa Cruz', max_price: 400.00)
+  def self.bikes(search_opts)
+    make = search_opts[:make]
+    max_price = search_opts[:max_price]
+
+    results = self.all.select do |posting|
+      posting.category == 'bikes' &&
+        posting.make == make &&
+        posting.price < max_price
+    end
+
+    return results
+  end
+
+  Craigslist.bikes({})
+
+  class Posting
+    attr_reader :category, :title, :price, :make
+
+    def initialize(fields)
+      @category = fields[:category]
+      @title = fields[:title]
+      @price = fields[:price]
+      @make = fields[:make]
+    end
+
+    def save
+      ALL_POSTINGS << self
+    end
+  end
+end

session-notes/2015-02-14/craigslist/craigslist.rb

@@ -0,0 +1,40 @@
+require_relative './craigslist.rb'
+
+# TESTS ---------------------------------------
+
+my_bike = Craigslist::Posting.new(
+            category: 'bikes',
+            title: 'My Mountain Bike for Sale',
+            price: 350.00,
+            make: 'Santa Cruz'
+          )
+
+# Test Craigslist::Posting attributes
+
+p my_bike.category == 'bikes'
+p my_bike.title == 'My Mountain Bike for Sale'
+p my_bike.price == 350.00
+p my_bike.make == 'Santa Cruz'
+
+# Test Craigslist::Posting persistence
+
+p Craigslist.all.count == 0
+my_bike.save
+p Craigslist.all.count == 1
+
+# Test Craigslist.all returns all postings
+
+bike_two = Craigslist::Posting.new(category: 'bikes', title: 'Carbon Fibre Racing Bike', price: 500.00, make: 'Raleigh')
+bike_two.save
+
+p Craigslist.all.count == 2
+p Craigslist.all.all? { |item| item.class == Craigslist::Posting }
+
+# Search for a bike by make and price
+car = Craigslist::Posting.new(category: 'cars', title: 'Volkswagen Rabbit', price: 1000.00, make: 'Volkswagen')
+car.save
+
+bikes = Craigslist.bikes(make: 'Santa Cruz', max_price: 400.00)
+# => return an array of Craigslist::Posting objects
+
+bikes.first.title == 'My Mountain Bike for Sale'