Monday, February 18th, 2008
Liberator Comet Platform: Free Edition
Category: Comet
, Java, JavaScript, Library
Caplin Systems, creator of the Liberator Comet platform have announced a free version which can be used for non-commercial applications and for evaluation.
Liberator includes a high-performance Comet server, a JavaScript client library, and a Java server integration library.
There are many examples such as the subscriptions sample which shows a page with realtime updating information for a variety of equities and foreign exchange data.
This is how a subscriber looks in JavaScript:
HTML:
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<script type="text/javascript" id="sl4b" src="/sl4b" rttpprovider="javascript"></script>
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<script type="text/javascript">
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// class definition for SimpleSubscriber
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function SimpleSubscriber(sObjectName)
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{
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// Store the object name as a member variable so it can be used later on; no subscription can
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// take place until this object's ready() method has been called.
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this.m_sObjectName = sObjectName;
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// Invokes the initialise method on the base class (i.e. SL4B_AbstractSubscriber), this
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// must be called within the constructor of all SL4B_AbstractSubscriber subclasses.
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this.initialise();
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}
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// Defines SimpleSubscriber as a subclass of SL4B_AbstractSubscriber.
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SimpleSubscriber.prototype = new SL4B_AbstractSubscriber;
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// Overrides the ready() method from SL4B_AbstractSubscriber; once this method has been invoked
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// it becomes safe to make object subscriptions.
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SimpleSubscriber.prototype.ready = function() {
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// Use the RTTP provider to setup the subscription; a reference to this object is passed in
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// since it will be acting as the subscriber, and will receive the notification updates.
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SL4B_Accessor.getRttpProvider().getObject(this, this.m_sObjectName);
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};
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// Overrides the recordUpdated() callback method from SL4B_AbstractSubscriber; this method will
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// be invoked whenever new object data becomes available.
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SimpleSubscriber.prototype.recordUpdated = function (sObjectName, sFieldName, sValue) {
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// add code to process the record update here
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}
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// Creates a new SimpleSubscriber to receive streaming updates for /DEMO/YHOO.
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new SimpleSubscriber("/DEMO/YHOO");
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</script>
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4 rating from 21 votes
Tell me that their framework doesn’t spell ‘initialize’ wrong.
They’re British, so I think us Americans actually spell it wrong. I think that’s why so many developers spell it init :)