rss_class.py

#!/usr/bin/python
# -*- coding: latin-1 -*-
#
# $Id: rss_class.py,v 1.23 2016/06/28 06:40:51 bob Exp $
# Raspberry Pi RSS feed class
#
# Author : Bob Rathbone
# Site   : http://www.bobrathbone.com
#
# License: GNU V3, See https://www.gnu.org/copyleft/gpl.html
#
# Disclaimer: Software is provided as is and absolutly no warranties are implied or given.
#             The authors shall not be liable for any loss or damage however caused.
#


import os
import time
import urllib2
from xml.dom.minidom import parseString
from log_class import Log
from translate_class import Translate

log = Log()
translate = Translate()

url = "/var/lib/radiod/rss"

# Tags to strip out
tags = ['<h1>', '</h1>',
	'<h2>', '</h2>',
	'<h3>', '</h3>',
	'<h4>', '</h4>',
	'<p>', '</p>', '<p/>',
	'<br>', '</br>','<br/>',
	'<strong>', '</strong>',
	'<title>', '</title>',
	'<description>', '</description>',
	]

class Rss:
        rss = []	# Array for the RSS feed
        length = 0	# Number of RSS news items
	feed_available = False
	rss_error = False # RSS Error (prevents repetitive error logging)

	def __init__(self):
		log.init('radio')
                if os.path.isfile(url):
			self.feed_available = True
		return    

	# Gets the next RSS entry from the rss array
	def getFeed(self):
		self.feed_available = False
		line = "No RSS feed"
		if self.length < 1:
			self.rss = self.get_new_feed(url)    
			self.length = self.rss.__len__()

		feed = "No RSS feed"
		if self.length > 0:
			self.feed_available = True
			line = self.rss.pop()
			self.length -= 1
			feed = translate.all(line)
			feed = feed.lstrip('"')
			feed = feed.lstrip('<')
			if not self.rss_error:
				log.message(feed,log.DEBUG)
		return feed

	# Is an RSS news feed available
	def isAvailable(self):
		return self.feed_available

	# Get a new feed and put it into the rss array
	def get_new_feed(self,url):
		rss = []
                if os.path.isfile(url):
			rss_feed = self.exec_cmd("cat " + url)
			try:
				file = urllib2.urlopen(rss_feed)
				data = file.read()
				file.close()
				dom = parseString(data)
				dom.normalize()
				rss = self.parse_feed(dom)
				self.rss_error = False # Clear RSS Error
				log.message("Getting RSS feed: " + rss_feed,log.INFO)
			except:
				if not self.rss_error:
					log.message("Invalid RSS feed: " + rss_feed,log.ERROR)
					self.rss_error = True  # Set RSS error
				rss.append("No RSS feed found")
		return rss
		
	def parse_feed(self,dom):	
		rss = []
		for news in dom.getElementsByTagName('*'):
			display = False
			line = news.toxml()
			line = line.replace("&lt;", "<")	# Replace special string
			line = line.replace("&gt;", ">")
			
			msg =  "LINE:" + line
			line = line.lstrip(' ')
			if (line.find("VIDEO:") != -1):
				continue
			if (line.find("AUDIO:") != -1):
				continue
			if (line.find("<rss") != -1):
				continue
			if (line.find("<item") != -1):
				continue
			if (line.find("<image") == 0):
				continue
			if (line.find("<title>") >= 0):
				display= True
			if (line.find("<description>") >= 0):
				display= True

			if display:
				title = ''
				description = ''
				line = line.rstrip(' ')
				line = line.replace("![CDATA[", "")
				line = line.replace("]]>", "")

				if (line.find("<description>") == 0):
					description = line.split("</description>", 2)[0]
					description = self._strip_string(description, "<img", "</img>")
					description = self._strip_string(description, "<a href", "</a>")
					description = self._strip_string(description, "<br ", "</br>")

				if (line.find("<title>") >= 0):
					title = line.split("</title>", 2)[0]

				if len(title) > 0:
					for tag in tags:	# Strip out HTML tags
						title = title.replace(tag, "")
					rss.append(title)

				if len(description) > 0:
					for tag in tags:	# Strip out HTML tags
						description = description.replace(tag, "")
					rss.append(description)

				self.feed_available = True
		rss.reverse()
		return rss

	# Execute system command
	def exec_cmd(self,cmd):
		p = os.popen(cmd)
		result = p.readline().rstrip('\n')
		return result

	# Strip string (between tags)
	def _strip_string(self, text, s_start, s_end):
		new_text = text
		
		try:
			while new_text.find(s_start) > 0:
				idx_start = new_text.find(s_start)
				replace_str = new_text[idx_start:]
				idx_end = replace_str.find(s_end)
				if idx_end < 0:
					idx_end = replace_str.find("/>")
					len2 = 2	
				else:
					len2 = len(s_end)
				replace_str = replace_str[0:idx_end + len2]
				new_text =  new_text.replace(replace_str,'')
		except:
			new_text = text
		return new_text

# End of class