Amazon Scraper

Lib.hs

{-# LANGUAGE OverloadedStrings #-}

module Lib where

import Text.HTML.Scalpel
import Data.Maybe (fromMaybe)
import Data.Char
import Control.Applicative
import Text.Read (readMaybe)

searchUrl :: String -> String
searchUrl query = "http://www.amazon.com/s/?field-keywords=" ++ query

data Result = Result {
    title :: String,
    rating :: (Maybe Float)
  }
  deriving Show

allResults :: String -> IO [Result]
allResults query = fromMaybe [] <$> scrapeURL (searchUrl query) results
   where
       results :: Scraper String [Result]
       results = chroots ("li" @: [hasClass "s-result-item"]) result

       result :: Scraper String Result
       result = do
           title  <- text $ "h2"
           rating <- optional $ text $ "i" @: [hasClass "a-icon-star"] // "span"
           return $ Result title $ rating >>= parseRating

parseRating :: String -> Maybe Float
parseRating = readMaybe . (takeWhile $ not . isSpace) . (dropWhile $ isAlpha)

Main.hs

module Main where

import Lib

main :: IO ()
main = do
  putStrLn "Enter your Amazon query:"
  results <- allResults =<< getLine
  mapM_ printResult results

printResult :: Result -> IO ()
printResult (Result item rating) = do
  putStrLn item
  putStrLn $ maybe "N/A" show rating
  putStrLn ""