Symbian.org/RssReader.js
author ivanl
Tue, 21 Jul 2009 14:30:35 +0100
changeset 13 3a1db8573f1e
parent 10 07ac2f6a36a9
child 18 b73e6caf0031
permissions -rw-r--r--
cleanup

///////////////////////////////////////////////////////////////////////////////
// RSS Reader from WRTKit examples, modified for Symbian.org

// RSS reader class

function RssReader(aFeedName, aFeedUrl, aFeedPresenter, aParent, aResponseParser){
	this.responseParser = aResponseParser;
	this.feedUpdateBroker = null;
	this.feedUpdateBrokerActive = false;
	this.feedName = aFeedName;
	this.feedURL = aFeedUrl;
	this.feedUpdateForced = false;
	this.feedItemControls = [];
	this.feedLastModified = 0;
	this.ignoreContent = false;
	this.hasData = false;
	this.startFromItem = 0;
	this.maxItems = 0;
	
	var caption = createCaption(aFeedName);
	
	ListView.prototype.init.call(this, null, caption);
	this.previousView = aParent;
	if (aFeedPresenter != null) {
		this.feedPresenter = aFeedPresenter;
		this.feedPresenter.init(this);
	} else {
		this.feedPresenter = new HtmlFeedPresenter(this);
	}
	
	// add pre-amble items (latest posts, new thread, reply etc)
	this.feedPresenter.addPreambleItems();
}	

RssReader.prototype = new ListView(null, null);
	
// Callback function that gets called when a feed update has completed.
RssReader.prototype.feedUpdateCompleted = function(event){
	// remove cancel button
	this.setupSoftKeys();
	if (event.status == "ok") {
		// if there aren't any feed items yet, we'll hide the progress dialog
		
		// check if the feed has updated
		if (event.lastModified != this.feedLastModified) {
			// remember the last modified timestamp
			this.feedLastModified = event.lastModified;
			
			// feed fetched and parsed successfully
			this.setFeedItems(event.items);
			
			// focus the first feed item control
			// (but only if we are in the main view)
			if (this.feedItemControls.length > 0 ) {
				this.feedItemControls[0].setFocused(true);
			}
		}
		uiManager.hideNotification();
	}
	else if (event.status != "cancelled") {
		// show error message
		uiManager.showNotification(3000, "warning", "Error while updating feed!");
	}
	
	// reset the broker 
	this.feedUpdateBroker = null;
	this.feedUpdateBrokerActive = false;
	
	// reset commanded feed update flag
	this.feedUpdateForced = false;
}
	
// Removes feed items.
RssReader.prototype.removeFeedItems = function (){
	// remove all current feed items from the main view
	for (var i = 0; i < this.feedItemControls.length; i++) {
		this.removeControl(this.feedItemControls[i]);
	}
	
	// reset feed item control array
	this.feedItemControls = [];
}
	

// Sets feed items.
RssReader.prototype.setFeedItems = function (items){
	// start by removing all current feed items
	this.removeFeedItems();
	
	if (items.length == 0) {
		this.feedPresenter.showNoItems();
	}
	else {
		// create new feed items and add them to the main view
		// use feed item pool to recycle controls
		for (var i = 0; i < items.length; i++) {
			var item = items[i];
			this.feedPresenter.show(item);
		}
		
	}
	this.hasData = true;
}
	
	
// Update feed
RssReader.prototype.update = function(forceFeedUpdate){
	if ( this.hasData && !forceFeedUpdate ) {
		return;
	}		
	this.feedUpdateForced = forceFeedUpdate;
	
	// check if a feed update has been scheduled, if it's time to update now,
	// and if there's no update currently in progress and if we're in the main view
	if ((this.feedURL != null) && (!this.feedUpdateBrokerActive) ) { //&& (uiManager.getView() == this) ) {
		// fetch the feed from the specified URL
		this.feedUpdateBrokerActive = true;
		this.feedUpdateBroker = new FeedUpdateBroker();
		this.feedUpdateBroker.startFromItem = this.startFromItem;
		this.feedUpdateBroker.maxItems = this.maxItems;
		
		if ( this.responseParser != null ) {
			this.feedUpdateBroker.responseParser = this.responseParser;
		}
		this.feedUpdateBroker.ignoreContent = this.ignoreContent;
		this.feedUpdateBroker.fetchFeed(this.feedURL, this);
		// allow cancelling
	    if (window.widget) {
			var self = this;
			menu.setRightSoftkeyLabel("Cancel", function(){
				self.feedUpdateBroker.cancel(); self.setupSoftKeys();
				uiManager.hideNotification();
				});
	    }
		uiManager.showNotification(-1, "wait", "Loading feed...", -1);
	}
}