1. Fachpraktikum Graphische Benutzungsoberflächen Sommersemester 2008 Mark Giereth, Steffen Koch, Christoph Müller, Guido Reina, Christiane Taras, Harald Bosch Aufgabe 5: RSS/ATOM Proxy

2. Traditional browser-webserver interaction is form-based On submit content of previous (HTML-)page is dropped According to an http-request including aparameters a new (HTML-)page is recieved and displayed Web Container Institut für Visualisierung und Interaktive Systeme – Universität Stuttgart2 Basic concept of the RSS-Feed-Proxy Feed Proxy News Feeds Iterative Polling Cycle 1 Browser Iterative Polling Cycle 2 http - request http - response http - request http - response Browser AJAX- Handler Using asynchronous JavaScript and XML it is possible to update content partially Advantage of such an approach is reduction of bandwidth and increased usability (may not be true for the visually impaired) by better responsiveness Iterative tasks can be accomplished by polling

3. Institut für Visualisierung und Interaktive Systeme – Universität Stuttgart3 Functionality of the Feed Proxy Three requests allowed Use AJAX to perform requests (test by browser) and handle results Encode parameters in requests (get or post) Web Container Feed Proxy News Feeds Iterative Polling Cycle 1 http - request http - response Browser subscribe_feeds unsubscribe_feeds get_subscribed_feeds xml-response

4. First steps of client development Download Apache Tomcat 6.x http://tomcat.apache.org/download-60.cgi Install it by unzipping it into arbitrary folder Test Tomcat by starting it and browsing to: http://localhost:8080 Checkout the feed proxy project Adapt localconfig.properties file within project Run ANT task deploy on project Try to browse to: http://localhost:8080/FeedServer/feed.server?action=subscribe_feeds&feedUrl= Place your developments under corresponding subfolders of web Institut für Visualisierung und Interaktive Systeme – Universität Stuttgart4

5. 5 Requirements for the client Subscription of new feeds Selection of subscribed feed resulting in display of feed entries Errors have to be presented appropriately Automatic update of all feeds Availability of new articles has to be signaled to the user Feed sites as well as news have to be accessible by click (open in new window) CSS has to be used Loading-bar should be displayed when ajax request is performed

6. Fragen?