FachpraktikumGraphische BenutzungsoberflächenSommersemester 2008

Mark Giereth, Steffen Koch, Christoph Müller, Guido Reina, Christiane Taras, Harald Bosch

Aufgabe 5: RSS/ATOM Proxy

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 Stuttgart 2

Basic concept of the RSS-Feed-Proxy

Feed Proxy NewsFeeds

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

Institut für Visualisierung und Interaktive Systeme – Universität Stuttgart 3

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 NewsFeeds

Iterative Polling Cycle 1

http - request

http - responseBrowser

subscribe_feedsunsubscribe_feeds

get_subscribed_feeds

xml-response

First steps of client development

Download Apache Tomcat 6.xhttp://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 Stuttgart 4

Institut für Visualisierung und Interaktive Systeme – Universität Stuttgart 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

Fragen?