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Hildon Event Feed

Latest revision as of 19:54, 4 October 2012

Hildon Event Feed is an event feed application and widget for Maemo5, with the purpose of display events posted by third-party applications and scripts. The event feed provides several DBus methods that can be used for posting events, removing events and adding refresh actions, which can be called using dbus-send or via one of the higher-level DBus APIs using Python, Qt etc.

The Hildon Event Feed DBus object is located at:

• Service: com.maemo.eventFeed
• Path: /
• Interface: com.maemo.eventFeed

[edit] DBus Methods

addEvent

Adds an event to the event feed.

Takes the following arguments:

sourceName (string): The name used to identify the source of the event. Must be unique to the source.

sourceDisplayName (string): The name representing the source for display purposes in the event feed UI.

icon (string): The path to the icon for the source. Can be a path to a local file, or a link to a file on a remote server.

title (string): The title of the event.

body (string): The description/details of the event.

images (array of strings): Images for the event (e.g video thumbnails). Only the first two images will be displayed. As with the icon, HTTP links can be used.

footer (string): Useful for indicating the original source of the event (e.g twitter username).

timestamp (string): The date and time of the event. 

Accepted formats for timestamp:

• Timestamp in msecs since epoch, e.g '1349044868990'
• String in ISO format, e.g '2012-09-30T23:41:08.000Z'
• String in Qt::TextDate format, e.g 'Sun Sep 30 23:41:08 2012'
• String format 'Sun, 30 Sep 2012 23:41:08'

action (string): The action to be called when the user taps on the event in the event feed UI.

Accepted formats for action:

• dbus:session [service] [path] [interface] [method] [argument(s)] For DBus calls on session bus.
• dbus:system [service] [path] [interface] [method] [argument(s)] For DBus calls on system bus.
• exec [command] [argument(s)] For calling an application/script directly.

Returns:

eventId (long) if successful, else -1

removeEvent

Removes the specified event from the event feed.

Takes the following arguments:

eventId (long)

Returns:

success (boolean)

removeEventsBySourceName

Removes all events with sourceName equal to that specified.

Takes the following arguments:

sourceName (string)

Returns:

success (boolean)

addRefreshAction

Adds a refresh action for the specified source. This will be called when the user chooses to refresh the event feed.

Takes the following arguments:

sourceName (string)

refreshAction (string): Accepted formats are the same as for event action.

Returns:

success (boolean)

removeRefreshAction

Removes the refresh action for the specified source, if it exists.

Takes the following arguments:

sourceName (string)

Returns:

success (boolean)

getRefreshAction

Retrieves the refresh action for the specified source, if it exists.

Takes the following arguments:

sourceName (string)

Returns:

action (string) if it exists, else an empty string.

[edit] Examples

Adding an event

dbus-send

dbus-send --print-reply --type=method_call --dest=com.maemo.eventFeed / com.maemo.eventFeed.addEvent string:'my_source' string:'My Source' string:'/path/to/my/icon.png' string:'My Event' string:'This is an event' array:string:'/path/to/image/one.png', '/path/to/image/two.png' string:'Event footer' string:'2012-10-01T16:00:08.000Z' string:'exec /path/to/my/script argument'

Python

import dbus
import datetime

current_date_time = datetime.datetime.now().strftime("%Y-%m-%dT%H:%M:%S")

bus = dbus.SessionBus()
iface = dbus.Interface(bus.get_object("com.maemo.eventFeed", "/"), "com.maemo.eventFeed")

event_id = iface.addEvent('my_source', 'My Source', '/path/to/my/icon.png', 'My Event', 'This is an event', ['/path/to/image/one.png', '/path/to/image/two.png'], 'Event footer', current_date_time, 'exec python /path/to/my/script argument')

if event_id > 0:
    print event_id
else:
    print 'Error adding event'

Example Python script to retrieve YouTube videos and add them to the event feed

#!/usr/bin/env python

from __future__ import with_statement
import urllib2
import simplejson
import dbus
import datetime
import sys

LAST_RUN_DATE_TIME_FILE = '/home/user/Event Feed/examples/YouTube/last_run.txt' # File to read/write serialized date/time when script was last run.
SCRIPT_FILE = '/home/user/Event\ Feed/examples/YouTube/get_youtube_videos' # Path to the script.

def get_youtube_videos(query):
	""" Retrieve YouTube videos and populate the Hildon Event Feed
	
	    Usage: get_youtube_videos [query]
        """
    
	query = query.strip().replace(' ', '+')
	video_feed = 'http://gdata.youtube.com/feeds/api/videos?v=2.1&max-results=20&alt=json&orderby=published&q='
	video_fields = 'entry(media:group(media:title,media:thumbnail,media:description,media:credit,yt:uploaded,yt:videoid))'
	
	source_name = 'youtube_example' # Identifies the source of the events. Must be unique to the source.
	source_display_name = 'YouTube' # Display name for the source in the event feed UI.
	icon = '/home/user/Event Feed/examples/YouTube/youtube_icon.png' # Icon to be displayed in the event feed UI.
	action = 'dbus:system com.nokia.osso_browser /com/nokia/osso_browser/request com.nokia.osso_browser load_url' # This will be called when the user taps on an item in the event feed. In this example, the video url is opened in the browser.
	refresh_action = 'exec python %s %s' % (SCRIPT_FILE, query) # This will be called when the user presses the 'Refresh' button in the event feed UI.
	
	bus = dbus.SessionBus()
	iface = dbus.Interface(bus.get_object('com.maemo.eventFeed', '/'), 'com.maemo.eventFeed') # Connect to event feed dbus object
	iface.addRefreshAction(source_name, refresh_action) # Add a refresh action to the event feed.
	
	last_run = script_last_run() # Time when script was last run. Will be used to check against the date/time of each video in the feed.
	
	result = urllib2.urlopen('%s%s&fields=%s' % (video_feed, query, video_fields)).read()
	json_result = simplejson.loads(result)
	
	try:
		result = json_result['feed']
		videos = result['entry']
	except:
		videos = []
		print 'Error retrieving video feed'
	
	for video in videos:
		try:
			group = video['media$group']
			video_id = group['yt$videoid']['$t']
			title = group['media$title']['$t']
			description = group['media$description']['$t']
			thumbnail = group['media$thumbnail'][3]['url']
			thumbnail2 = group['media$thumbnail'][4]['url']
			uploader = group['media$credit'][0]['$t']
			upload_date = group['yt$uploaded']['$t']
			
			try:
				item_date_time = datetime.datetime.strptime(upload_date[0: upload_date.find('.')], '%Y-%m-%dT%H:%M:%S')
			except:
				print 'Cannot parse item date/time. Using default'
				item_date_time = datetime.datetime.min
			
			if item_date_time > last_run:
				print iface.addEvent(source_name, source_display_name, icon, title, description, [thumbnail, thumbnail2], uploader, upload_date, '%s http://www.youtube.com/watch?v=%s' % (action, video_id))
		
		except:
			print 'Error processing video item'
			
	set_script_last_run(datetime.datetime.now().strftime('%Y, %m, %d, %H, %M, %S'))

def script_last_run():
	""" Read serialized date/time from last_run.txt. """
	
	date_time_string = 
	last_run = datetime.datetime.min
	
	try:
		with open(LAST_RUN_DATE_TIME_FILE, 'r') as file:
			date_time_string = file.read()
			file.close()
			
		if date_time_string != :
			try:
				last_run = datetime.datetime.strptime(date_time_string, '%Y, %m, %d, %H, %M, %S')
			except:
				print 'Saved date/time in incorrect format. Using default'
				
	except IOError:
		print 'Cannot read date/time from file. Using default.'
					
	return last_run
	
def set_script_last_run(date_time_string):
	""" Serialize the date/time the script was last run to last_run.txt. """

	try:
		with open(LAST_RUN_DATE_TIME_FILE, 'w') as file:
			file.write(unicode(date_time_string))
			file.close()
	except IOError:
		print 'Cannot write date/time to file'

if __name__ == '__main__':
	if len(sys.argv) == 2:
		sys.exit(get_youtube_videos(sys.argv[1]))
	else:
		print 'Usage: get_youtube_videos [query]'

Example Python script to retrieve an RSS feed (default is latest TMO threads) and post new items to the event feed.

#!/usr/bin/env python

from __future__ import with_statement
import xml.dom.minidom as DOM
import urllib2
import dbus
import re
import datetime
import sys

LAST_RUN_DATE_TIME_FILE = '/home/user/Event Feed/examples/RSS Feed/last_run.txt' # File to read/write serialized date/time when script was last run.
SCRIPT_FILE = '/home/user/Event\ Feed/examples/RSS\ Feed/get_rss_feed' # Path to the script.

def get_rss_feed(feed = 'http://talk.maemo.org/external.php?type=RSS2'):
	""" Retrieve the RSS feed (default is latest TMO threads) and post events to the Hildon Event Feed. """
	
	source_name = 'rss_feed_example' # Source of the events
	display_name = 'RSS Feed' # Source name displayed in the event feed UI
	icon = '/usr/share/icons/hicolor/64x64/hildon/general_rss.png' # Icon for the events in the UI
	action = 'dbus:system com.nokia.osso_browser /com/nokia/osso_browser/request com.nokia.osso_browser load_url' # This will be called when the user taps on an item in the event feed. In this example, the link is opened in the browser.
	refresh_action = 'exec python %s %s' % (SCRIPT_FILE, feed) # When this refresh action is added, the script will be called again (with same feed) when the 'Refresh' button is pressed in the event feed UI.
	
	bus = dbus.SessionBus()
	iface = dbus.Interface(bus.get_object('com.maemo.eventFeed', '/'), 'com.maemo.eventFeed') # Get the event feed dbus object
	iface.addRefreshAction(source_name, refresh_action) # Add the refresh action to the event feed.
	
	last_run = script_last_run() # Time when script was last run. Will be used to check against the date/time of each item in the feed.
	
	rss = urllib2.urlopen(feed).read()
	doc = DOM.parseString(rss)
	items = doc.getElementsByTagName('item')
		
	link = 
	title = 
	body = 
	images = []
	footer = 
	timestamp = 
		
	for item in items:
		for node in item.childNodes:
			nodeName = node.nodeName
			
			if nodeName == 'link':
				link = node.firstChild.data
			elif nodeName == 'title':
				title = node.firstChild.data
			elif nodeName == 'description':
				body = node.firstChild.data
			elif nodeName == 'dc:creator':
				footer = node.firstChild.data
			elif nodeName == 'pubDate':
				timestamp = node.firstChild.data
			elif nodeName == 'content:encoded':
				images = get_images(node.firstChild.data)
		
		try:
			item_date_time = datetime.datetime.strptime(timestamp[0:timestamp.rfind(' ')], '%a, %d %b %Y %H:%M:%S')
		except:
			print 'Cannot parse item date/time. Using default'
			item_date_time = datetime.datetime.min
		
		if item_date_time > last_run:
			print iface.addEvent(source_name, display_name, icon, title, body, images, footer, timestamp, '%s %s' % (action, link)) # If item is new, add an event to the event feed and print the reply.
		
	set_script_last_run(datetime.datetime.now().strftime('%Y, %m, %d, %H, %M, %S'))
	
def script_last_run():
	""" Read serialized date/time from last_run.txt. """
	
	date_time_string = 
	last_run = datetime.datetime.min
	
	try:
		with open(LAST_RUN_DATE_TIME_FILE, 'r') as file:
			date_time_string = file.read()
			file.close()
			
		if date_time_string != :
			try:
				last_run = datetime.datetime.strptime(date_time_string, '%Y, %m, %d, %H, %M, %S')
			except:
				print 'Saved date/time in incorrect format. Using default'
				
	except IOError:
		print 'Cannot read date/time from file. Using default.'
					
	return last_run
	
def set_script_last_run(date_time_string):
	""" Serialize the date/time the script was last run to last_run.txt. """

	try:
		with open(LAST_RUN_DATE_TIME_FILE, 'w') as file:
			file.write(unicode(date_time_string))
			file.close()
	except IOError:
		print 'Cannot write date/time to file'
	
def get_images(content):
	""" Try to extract image links from the content:encoded node. """
	
	images = re.findall('http://[^\s]+jpg|http://[^\s]+png', content)
	
	if len(images) > 2:
		images = images[0:2]
	
	return images
	
if __name__ == '__main__':
	if len(sys.argv) > 1:
		sys.exit(get_rss_feed(sys.argv[1]))
	else:
		sys.exit(get_rss_feed())

marxian 15:09, 4 October 2012 (UTC)