Re: [vtp-dev] Questions, directions, techie stuff

[Trip Gilman <trip@xxxxxxxxxxxxxxx>]

Title: Re: [vtp-dev] Questions, directions, techie stuff

David,

I’d like to share with you some diagrams that might clarify how the runtime architecture operates and is deployed.  The first diagram illustrates the general environment:


The designer produces the application definition (stored in our meta-language xml) and bundles it inside a web application archive along with our runtime components.  An instance of this runtime is instantiated by the application server during the first HTTP request.  This application definition is loaded by the runtime instance and processed by the process engine component.  The following diagram outlines the process at a high level from end to end:



As the definition is executed, small pieces of code called Actions are loaded, instantiated, and then run.  As a result of these Actions, interactive commands can be invoked.  These commands are configured with the data provided by the application developer during design time through the element properties dialogs.  The commands are then interpreted through the applicable platform layers.  The platform layers ultimately produce an interaction specific artifact.  In the case of VXML, the platform layers produce a VXML document that is then sent as the payload to the HTTP response.

At its core, the web application is actually an Equinox instance hosted inside a special servlet that acts as a bridge between the application server and the OSGi platform.  The runtime is a conglomeration of components and services.  These components are packaged into several bundles and features.  The following diagram places these components into context within the runtime as a whole:



To answer your question about the runtime, it is indeed part of the tooling in that it is part and parcel of the VTP codebase. However, as you theorize the meta-language is primarily only useful to the runtime as it describes the application in terms understood by the runtime.  That is not to say that the runtime available as part of the VTP is the only solution.  Other vendors that also conform to the runtime architecture have done work to allow their runtimes to execute our meta-language documents.  However, this is not a trivial task as the runtime brings an amazing set of features and capabilities to each and every application it executes.

I may not be understanding the approach you want to take with the tooling environment you propose.  The application of code generation directly from the IDE as an alternative to the existing web application export is definitely outside the scope and direction of this project.  That said, there may still be ways for you to achieve your overall goals and still leverage the capabilities of our project.  A couple of avenues I see are:

• Abandon the use of the code generation model.  This would be my personal suggestion, however from your earlier comments it appears that you already have an existing development investment down that path so it may not be a workable option.
• Create a new platform implementation that is capable of taking the generic interaction commands and producing the hybrid code/VXML artifacts you were discussing previously.
• Although not truly a solution to your original goal, there may still be many utilities and components of the VTP that might provide value to your efforts.
  

As far as documentation, there are no specific documents outlining the creation of a new platform implementation.  However, the interface is rather simple and the base class for the VXML platform fully implements it.  This allows you to simply override the results of the interactive commands you need to.

Trip Gilman

On 4/12/09 8:34 PM, "David Reich" <David.Reich@xxxxxxxxxxx> wrote:

> Hi Trip
> 
> Yes, this brings together (more formally stated) the things I was assuming 
> from watching the evolution as I read through the mailing list and newsgroup 
> archive.  I was also trying to bridge what IBM had done in it's own Voice 
> Toolkit versus the tidbits that got contributed (BM has way more than got 
> contributed so I needed to digest what did and did not go to Eclipse).  So I 
> think from my inferences, and reading your reply that it is safe to say that 
> essentially, the IBM code contribution was the base editors built on WTP 
> (which actually was needed at the time because the XML editing framework was 
> missing a number of features), and now that the XML framework is better that 
> shoving the SRGS, or VXML or CCXML DTDs at the editing framework now will do 
> essentially the same thing - right?
> 
> Assuming that, I'm starting to feel a little warmer and fuzzier.  My next 
> question though, is this metalanguage and common runtime architecture you 
> describe.  Is this part of the tooling?  Or some runtime from OpenMethods that 
> is required in a server environment and the application/interaction with the 
> user as described by the metalanguage is only useful with this generator at 
> run time?  I hope it is the former.
> 
> I like the idea of the interaction model, and that one can use it for SMS as 
> well as voice etc, but I wonder about the rendering model, and hope it's just 
> my learning of how the current VTP is built, but as you pointed out, every 
> consumer of user of this tool will have specific language requirements, for 
> example, it I use VoiceGenie vs IBM Voice Server vs... because for my 
> VoiceXML, I will have specific subtleties (notice how I do not say Nuances? 
> ;-) in what I want generated.
> 
> Also, in my specific case, we do not use JSPs, but a JSP-like mechanism and 
> would want to hook in to render this other language as the target (we have a 
> framework that consumes this with some VoiceXML embedded in it, and it 
> generates other VoiceXML and CCXML) and would like to be able to write a 
> module that generates our "markup" as well.  If this is part of the tooling, 
> great.  Is there any doc available yet on that?  Or is this what Randy was 
> referring to?
> 
> I wonder if we can start a weekly call perhaps, since I'd like to see about 
> regenerating interest in this tool, especially when you have positioned it as 
> a user interaction modeler as this could have other benefits in other areas 
> such as multimodal/text messaging (e.g. Yap) or others.  Also, a little more 
> efficient than the mailing list at least to get things moving across multiple 
> parties again.
> 
> Whaddayathink?
> 
> 
> 
> David Reich
> AIT Architect,  Adeptra, Inc.
> 
> 
> 
> 
> 
> ________________________________
> From: Trip Gilman <trip@xxxxxxxxxxxxxxx>
> Reply-To: Voice Tools general developers <vtp-dev@xxxxxxxxxxx>
> Date: Sun, 12 Apr 2009 20:27:01 -0400
> To: Vtp-Dev <vtp-dev@xxxxxxxxxxx>
> Subject: Re: [vtp-dev] Questions, directions, techie stuff
> 
> David
> 
> First I'd like to thank you for your interest in the VTP and welcome you
> back to the industry.  I've provided a broad overview of where we are now as
> a project and also weaved some of my detailed thoughts on your questions
> into your original text below.
> 
> You are correct in that the current VTP is a complete departure from the
> codebase originally contributed by IBM.  I would like to take a moment to
> point out some of the fundamental changes between the original vision and
> our current direction and then discuss the reasoning for our approach.
> 
> First, the xml editors for GRXML grammars have been replaced with the
> generic xml editor provided by the basic eclipse development framework.  The
> original VTP utilized a customized xml editor based on those provided by the
> Web Tools Project.  The removal of this dependency reduced the overall size
> of our software by nearly 100M and eliminated several layers of complexity
> for no real loss of functionality.
> 
> Second, and probably the most centrally important, the VTP employs a common
> runtime architecture as opposed to code generation.  I don't want to focus
> on the choice between the two, but I would like to illustrate how we
> leverage our choice of a runtime architecture.
> 
> The voice tools project has almost become a misnomer.  Our development and
> runtime frameworks are no longer just for VXML, but have evolved into a
> generic platform for describing interactions.  The core of the development
> environment is blissfully unaware that the user intends to use the
> application they are creating as the source of a VXML interaction.  The
> runtime environment executes the interaction within a process engine that
> emits basic interactive commands that are interpreted into VXML at the final
> moment.  This is important to understand as this philosophy is pervasive
> throughout the codebase.
> 
> The user creates applications by adding Actions to a canvas and then
> defining the transitions between those actions.  The most common Actions,
> such as a Menu or a Prompt(Output), are standard components provided by the
> framework.  However, third-party developers can easily and quickly create
> their own action libraries for users to use.  I want to reiterate that
> although these actions may share the names of the elements that make up
> VXML, they are not the same.
> 
> The designer has an abstraction framework that models the nuances of
> interaction types on these actions, allowing interaction specific
> configuration.  For example, the VTP comes with an implementation of the
> Voice (VXML) interaction type.  This provides interaction specific UIs to
> manage VXML settings such as barge-in and dtmf/speech entry.
> 
> This framework has been used to create other interaction types such as
> Instant Messaging.  An application can support any combination of
> interaction types the user has available to them.  This is very powerful in
> that the same application deployed once, could drive the interactions of
> both telephone and IM based customers.
> 
> On the runtime side, things are equally abstracted.  As I mentioned earlier,
> the artifacts produced by our designer (upon export) are actually process
> meta-language documents.  These documents are executed by the process engine
> at the core of the runtime.  As the process is executed, interactive
> commands are generated.  These commands are then filtered through a platform
> abstraction layer and evaluated.  The VTP includes a platform layer designed
> for VXML interactions that is capable of transforming the interactive
> commands into their representative VXML documents.
> 
> The platform abstraction layer is powerful on two fronts.  First, it allows
> the VXML generation process to be customized to the specific VXML Browser
> platform requesting the document.  This means that a single application
> instance can service multiple VXML platforms simultaneously without
> re-export or compilation.  The VXML session could even bounce back and forth
> between the platforms without issue.
> 
> Second, the platform abstraction is open to third-parties to add
> implementations for additional platform types and output mechanisms.  The
> VXML platform generates XML documents and processes requests and responses
> over HTTP.  Other implementations could simply execute direct API calls to
> other software or hardware, never producing a document artifact.  They could
> also support transports other than HTTP.
> 
> I hope this helps illuminate the project for you.
> 
> Trip Gilman
> 
> 
> On 4/10/09 8:33 PM, "David Reich" <David.Reich@xxxxxxxxxxx> wrote:
> 
>> Hi,
>> 
>> First, let me (re)introduce myself.  David Reich, formerly of IBM.  I was
>> involved in the creation of VoiceXML and was the guy who was the initial
>> driver behind all of the Eclipse-based voice tooling, first from IBM's
>> toolkit, and it's subsequent donation to Eclipse and VTP.  I've since left 
>> IBM
>> and as you know, IBM's involvement in voice has waned.  But, I am now with a
>> new company, happily back in VoiceXML, CCXML and SRGS, and we are doing a lot
>> with VoiceXML and CCXML and I was brought in to drive our development team,
>> and one of the areas I am looking at is the development of our application
>> artifacts, and VoiceXML application generation.
>> 
>> With that, I've spen the last couple of days figuring out where things are
>> with this project, how we can use it, how we might give back to it and so on.
>> From what I've been able to see thus far, it looks like the current code base
>> bears little to no resemblance to the VTP 1.0 code that came in from my 
>> former
>> team, but, on the other hand, there is a nicely-coming-along visual editor
>> without which all VTP would be is the XML editor with DTDs plugged in and
>> while nice, not really compelling.
>> 
>> I was hoping to provoke some discussion and see about some combination of 
>> code
>> to create an even more gener(ic)ally useful environment.  With that, some
>> thoughts and the hope we can put some other things together.  In no specific
>> order:
>> 
>> 
>>  *   The original IBM code seems to be gone.  When things moved to SVN, the
>> CVS repository went away, so unless someone has that source code, it's gone
>> forever (I've checked with the (remnants of) the IBM team, and without some
>> serious effort, it's not readily available.  So, how can we get that back,
>> even if we only want to take small bits (or even none?) of it?  There's got 
>> to
>> be useful things there, and we should still look at that.
> 
> The original IBM source still exists, however it is not readily available as
> it has been archived from CVS by the webmasters to reclaim space and keep
> the repositories current.  If you would like a copy of the archive, I would
> be more than happy to make the request for you.
> 
>>  *   In the original tools, of which the VTP 1.0 code was a part, the vision
>> was a call flow builder similar to what WebMethods has been working on, but
>> rather than generate a metalanguage, have it generate VoiceXML and have a
>> tabbed view (kinda like FrontPage) where you see the call flow view, and the
>> VoiceXML source view, and the editor would allow you to tweak the VoiceXML in
>> source edit mode, affording finer-grained control of the VoiceXML.
> 
> Very early on we abandoned code generation in favor of a runtime
> architecture to overcome several challenges we were faced with when
> developing applications in the field.  Each time we encountered a new VXML
> platform, there were always a myriad of minute differences or interesting
> interpretations of the specification.  We considered just coding these
> changes into the code generation piece until we ran into a client that had
> multiple platforms in service.  The solution was to export the application
> twice, once for each platform.  This instance was one of the driving forces
> in the transition to a runtime architecture.
> 
> Another driving factor of the move, was the realization that we were already
> building a runtime, just not officially and not effectively.  We had
> developed a loose library of utility functions and were using them over and
> over again in all our applications.  More and more functionality was being
> encoded into this framework in an effort to hasten development.  Making the
> runtime a first class citizen in the architecture allowed us to leverage the
> advances we had made while removing most of the hurdled we were facing.
> 
>>  *   Linkages to the Eclipse framework for task-list items in validation,
>> warnings, errors, etc.
> 
> Absolutely, integration to the tagging systems in Eclipse is currently on
> the wish list.
> 
>>  *   Enabling (as Randy has told me is the direction) a derivative or
>> extension plugin to generate code that spews forth VoiceXML.  This could take
>> the form of the OpenMethods servlet, or even perhaps an extension one could
>> write
>> 
>> to do JSPs, or other types of markup/tag/metalanguage since not everyone will
>> want just the VoiceXML from the OpenMethods servlet, or wants to make further
>> tweaks to the VoiceXML.
> 
> I won't say that it would be impossible to generate the resulting VXML from
> an application statically, but at some point you'd end up recreating the
> logic inherent in the runtime in JSP or some other language.  In the case of
> multi-modal applications, simply duplicate the application several times
> over.
> 
> On a side note, the modification of generated code after export can be a
> very tempting practice as many problems can be solved quickly this way.
> However, I never recommend the use of this.  It places a process requirement
> on the development and deployment staff to always re-apply the changes to
> the code each time there is an update.  What happens if changes made to the
> code require the workaround to be updated?  This can easily balloon into a
> maintenance nightmare.  I would say that it should be the goal of any
> system, whether code generation or runtime, to avoid the need of this at all
> costs.
> 
>>  *   A broader property sheet for each call element in the palette on the
>> canvas to specify items such as barge-in, SSML tags or information, prompt
>> audio files to be played and so on. Specifically, the block would play one of
>> a set of prompts based on current state (such as "Welcome to..."  or "Welcome
>> back to..." based on some global variables in the ECMAscript for example.
>> This tool should should hopefully allow for the export of this property sheet
>> data in different formats, but then again, as open source, we can work
>> together on extensions for our specific needs and write the hooks and
>> extension code for different needs.
> 
> The designer already supports this type of configuration in several ways.
> At a base level, the developer can use _javascript_ variables to indicate
> prompt content.  SSML can also be included in prompt content simply as text.
> At a higher level, the designer employs a system called branding to allow
> very detailed configuration for different user segments.  Branding can be
> used for personalization, line of business differentiation, or even
> multi-tenanting of an application.
> 
> On the export aspect of this, I assume you intend to use the artifacts
> within a static JSP/VXML document.
> 
>>  *   Have the palette be extensible where one can take prebuilt modules (say
>> an authentication subflow) add them to the palette, and drop it into a new or
>> existing application.
> 
> The designer is fully extensible.  Third-parties can easily publish
> additional modules for use.  Developers are also able to package up common
> call flow elements into reusable components called dialogs or even
> significant portions of a call flow into a fragment.
> 
>> That's enough or now, but you get the general idea.   I'm hoping we can make
>> this a bit more granular and extensible, and some of that is in the earlier
>> code (yes, I also have a fondness for my baby ;-) and marrying that with the
>> newer code, I think we can do a lot here.
>> 
>> Comments?
>> 
>> Thanks....
>> 
>> David Reich
>> AIT Architect,  Adeptra, Inc.
>> 
>> 
>> 
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