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dSVG - A New Kind of Programming?
"It quickly became apparent that while getting a grasp of XSLT is difficult and time-consuming, even more time-consuming was all the scripting it took to create the level of interactivity required on the client via script. Thus we set about creating a library of generic script functions that would assist developers in creating their Web apps. But it didn't take long to realize that this was no good--you can't data-map and transform (via XSLT) functions like you can markup. And, unlike markup, it's much more difficult to auto-generate and customize script via an authoring tool. So I set about designing an XML markup language, implemented with script (so as to work in any SVG viewer), which would describe UI controls and behaviours, so as to facilitate the creation of SVG-based Web applications.
It was a programmer's dream. I was essentially being paid to develop a new kind of programming language. One that, like XSLT, is XML-based but is more procedural in nature and thus easier for the average developer to grasp. It's also easier for non-developers to grasp it, thus bringing SVG and application development to a whole new class of user. A year later, dSVG (Dynamic SVG) was unveiled to the public as part of the Corel Smart Graphics Studio. And as of yesterday, the full dSVG 1.1 Specification and Test Suite became available for download.
The UI controls were designed to allow complete customization of appearance, and to allow for use with forms without being tied to a forms-specific model. The behaviors were designed to be generic and higher level than DOM methods, so as to be more intuitive to non-developers. The resulting markup language allows data-driven Web applications to be created with little or no need for scripting.
While script is very useful and powerful, markup has many advantages:
- markup is more easily understood by non-developers
- markup can be easily data-mapped and transformed using XSLT
- markup can be easily generated via an authoring tool and customized by the author
- markup is semantically meaningful, promoting interoperability on the authoring side
- markup can be standardized, thus helping the adoption of SVG
dSVG was implemented with script so as to work in different SVG Viewers. However, Corel has proposed dSVG to the SVG Working Group in the hopes that through a collaborative effort, dSVG will lead to the eventual creation of standard markup for UI controls and behaviors. These could then be natively implemented, bringing about even more advantages:
- faster
- less data to transfer
- less need for a script engine on small devices (which can take up a significant part of the footprint)
The dSVG 1.1 spec and test suite was posted for download with the goal of allowing the developers and non-developers to experiment with the markup and to provide feedback. This feedback will help me to improve upon dSVG and will also help the SVG Working Group to better assess how the developer community feels about such standard markup being added to the spec for the purpose of developing SVG-based Web applications.
I hope you will take the time to read through the dSVG spec, try out the test suite, and perhaps even create some of your own content. As the creator, I am obviously passionate and excited about dSVG. And having seen how quickly even non-developers can create Web apps, I feel certain that XML-based programming makes sense and is the way of the future. But being a long-time reader of Slashdot, I would love to hear what the Slashdot community thinks. dSVG may not lead to world peace, but I think it has the potential to change the fundamental way in which Web applications are created.
I look forward to hearing your comments.
Sincerely,
Gord Bowman
Lead Developer, Corel Corporation"
...now all we need are some browsers with native SVG support. With the Mozilla SVG project still seemingly no closer to delivering a shippable release, and no hope whatsoever of MS releasing an SVG enabled IE, looks like we're stuck with the Adobe plugin for now. Until we get past that, I doubt SVG will enter the mainstream (more's the pity).
"The invisible and the non-existent look very much alike." -- Delos B. McKown
Shouldn't new standards be introduced using RFCs? I'm not sure if it's a good trend when they are presented first on Slashdot...
Okay, so when are the Mac OS X and Linux versions due out? This is a pretty amusing situation - a development studio/language for something that isn't viewable without a plugin on its only supported OS?
Can someone summarize if I am going to get 20-to-life and a cellblock husband if I download the spec?
Jeez, how many paragraphs into the legal requirements do you have to be before you realize that ain't reeeeeal conducive to getting people to beta/bug track/improve your product for free?
PDHoss
======================================
Writers get in shape by pumping irony.
Wow, this actually got posted. Cool. Let me first say that the dSVG 1.1 spec is still evolving. There's lots of room for improvements. For instance, there's an 'if' element, but no 'elseif' or 'else' elements yet. Those are obviously needed. I originally thought that a DTD could not (or should not) define an element as being dependent upon a sibling, but after talking with some XML experts at the SVG Open conference in Vancouver this past week, I see now that I was wrong. Another needed feature is some kind of a fallThrough="true|false" attribute for the 'case' elements within a 'switch' element--mimicking the 'break' statement but in a more XML-ish way.
One huge area for improvements is in the design of the skins. It seemed like a good idea at the time, but I now see that it has limitations both for performance and for the creation of custom UI controls. More on that in a separate comment...
The fact that dSVG is implemented with script is, for now, a good thing because it allows us to make changes to the spec without the viewer, since the implementation gets passed along with the content. And for previously written content, the Corel Smart Graphics Studio (CGSG) IDE will automatically convert from the old version of dSVG to the new version (via XSLT).
I have a big list of ideas for improvements, but it's back at home and I'm still in Vancouver for a few more days attending meeting (so I apologize in advance if I am not always responding in a prompt manner). I'm really interested to see what other developers think of the spec thus far and how it could be improved.
You can find some demo apps at www.corel.com/smartgraphics/resources. As for apps created by customers, I don't know.
There is no way I am going to 'read and understand' all that legal language. I would rather create my own competing specification than do that.
So, either release it under a license I can understand (one consisting of ten or less paragraphs) or forget it!
- -
Are you an SF Fan? Are you a Tru-Fan?
SVG is a Good Thing, and it would be fantastic if it had broader browser support. Is anybody sufficiently familiar with the dark corners of the standard to explain why we don't see more implementations? Would it really be so hard for Adobe to update their Linux implementation to work with current browsers? Why isn't Mozilla/SVG farther along?
Cantankerous old coot since 1957.
Since you have already submitted the spec to the W3C SVG WG, it's already public knowledge, and there's no reason to hide it behind legalese, right? Can't you just provide a link straight to it?
I'm sure a lot of other people are more interested in the spec than anything else. If you want them (and me) to take a look at dSVG, please make the spec available by itself.
Thanks!
Easy, automatic testing for Perl.
IDE's to make programming a language easier is always a good thing. Vector graphics client is still dominated by Flash, but demand for more widespread SVG clients will occur when there are apps for it.
HTML pasted from the Spec, judge for yourself how it looks:
9.6 Example #1
dSVG sample behavior: focus - with added attributes focusGroup and focus
Content of file: dsvg:focus, dsvg:setTransform, dsvg:setAttribute, dsvg:setStyle, (added attributes dsvg:focus, dsvg:focusGroup)
The dsvg:focusGroup attribute adds the ability to store the ID of similar type elements that are assigned to that group.
Default focus can be given to an element (red circle above) by adding the dsvg:focus attribute to that element.
The red, blue, green circles are part of the focusGroup. The orange circle is not.
Click on the red, green and blue circles to set focus.
Hover over the 'red', 'green' and 'blue' text elements to set focus.
red
blue
green
orange
Hovering the mouse over the 'text' element with id="blueText causes the behaviors within the second 'focus' element to be run. When the first 'setStyle' behavior is run, its 'value' attribute, which is equal to:
%(textGroup@elementID)@cdata%
resolves to:
%blueText@cdata%
which then further resolves to:
blue
9.7 Example #2
Pushing the button will run the 'alert' behavior. Its 'message' attribute, which is equal to:
message= "%button1@label+ ' button ' + if(button1@selected == 'false' , 'is selected', 'is not selected')
which resolves to:
"button1@label + ' button ' + if( false , 'is selected', 'is not selected')
which further resolves to:
Evaluate button is selected
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"Hi, my company just came out with a new product and told me that I get a huge stinkin bonus if I managed to get an advertis^H^H^H^H^H^H^H^Harticle on it posted on /., so please click on this link..."
XML is simple and can be extended to fit almost any hierarchical data. An imediate benefit over ini format is that tags can be nested. There are also attributes of the tags. The reason XML is a big deal is it is a standard for marking up data that everyone can be happy with. The tags (both start and end) make it good for streaming as programs will know when the end of a block of data is. With xml schema or DTD's a specific language can be specified and an xml file can be verified to match that language easily.
The big deal isn't so much XML as the tools to manipulate XML data such as XSLT, XPath, DOM, and SAX.
- XML is more structured than INI files, tags can be nested, and can have attributes
- Several standard APIs for parsing, with multiple robust implementations
- Tools. Graphical XML editors and viewers, browser support, etc.
- XSLT is a nice scripting language for querying, formatting, rearranging, extracting, and building XML.
- Books and example code. There's a wealth of information on ways to use XML out there now.
- Critical mass. Enough people are using XML that you can exchange XML data with other people and expect them to know how to deal with it; and this large mass of applications means that the number of available tools, books, and resources just keeps growing.
You could compare XML to something like KIF or even XML's own parent SGML and ask "Why XML? Why now?" Critical mass, I think, is most important, more than anything else. You could do all the same things with another file format -- but you wouldn't have the range of tools, APIs, and features to choose from.Cantankerous old coot since 1957.
Since this appear to be a product by a comercial company, it sort of begs the questions : Is any patents filed relating to this, or is any existing patent involved? This includes any technology necessary to implement dSVG.
I apologize if I appear impolite, but I'm getting cynical as I age.
having seen how quickly even non-developers can create Web apps, I feel certain that XML-based programming makes sense and is the way of the future
By that criteria, PPOP (Power-point oriented programming) will be the wave of the future.
Table-ized A.I.
Some people think SVG and Flash directly compete, and others say no. But let's compare them for the case of creating data-driven applications. If you think that you don't have to code in Flash, then you must not have used it. It uses ActionScript, which is like a stripped-down ECMAScript (I think). But it's script. They have a UI for generating it, but it's mainly a succession of dropdown menus to finally insert an 'if' statment. So you're not freed from the need of actually knowing how to program or anything. But even if you did want to use a proprietary binary standard to create an enterprise-class data-driven application, can you and should you? Macromedia recently has tried to enter the Enterprise space to do this, but the idea of using a proprietary solution does not sit well with everyone. Especially when the alternative is to use a complete XML solution from beginning to end. Data-driven graphics and data-driven applications are just now starting to take off. And most of them are using SVG because it's an XML-language--thus you can data-map it easily with XSLT. Many argue that while SVG may be able to compete in the multi-media space, that's not where its strength lies. It's strength is in the visualization of data.
So, someone is creating an OO script/language for vector graphics...
Now that you've approaching Flash 5, can you please explain what you're hoping to accomplish?
Since their plug-in is commonly installed, their standards and documentation are apparently about as open and propriatory as yours, and since the number of people who can tell the difference between flash and dhtml is minimal, I'm not sure what the actual goal here is.
According to the normal timetable, Flash 7 should be released before the year is out and that seems to be your primary competitor. Unfortunately it also offers video, sound, raster graphics, and a good lead on a decent OO scripting langage. Oh wait, that's Flash 6.
Is there something new you're offering (other than a different set of lawyers) that we should be noticing?
No Zen is good zen
I'd like to see more open-source tools to create Flash format. Flash is a really good implementation of vector graphics - the engine is small, the files are small, and the system is very powerful. It took Macromedia three rounds to get it right (remember Director?) but finally, they did it.
Flash format is open, and there are a few non-Macromedia tools for it. But not enough. I once looked into doing a Flash tool for stock charts, so you'd get the raw data from the server and could pan, zoom, and do typical stock-chart operations like moving averages locally. It's possible.
.. we are and its fantastic. First of all, all our clients are running either Windows (98 to XP) or Mac OS X .. Adobe's plug-in is working just fine. We made a small modification to the Apache config file and feed our SVG files through the PHP interpreter first -- with PHP code embedded in the SVG file. Much of the data begin display on our clients SVG drawings are dynamic and sourced from a MySQL database. As the database is updated, the SVG drawings and figures change automatically. Saves a ton of work.
Screen shots screen shots , how'd I know i want it with out screen shots
For anyone scared to death by that EULA (I've been assured it's harmless), here is a couple of checkboxes that change the data of a text element. More examples to come.
G 11" xmlns:xlink="http://www.w3.org/1999/xlink" height="410px" width="744px" onload="init(evt)" viewBox="0 0 744 410">
h eckBox" autoScale="true" disabled="false" selected="false" height="12" width="12" y="70" x="50" label="Check Box 1" id="checkBox1">h eckBox" autoScale="true" disabled="false" selected="true" height="12" width="12" y="120" x="50" label="Check Box 2" id="checkBox2">
Gord
<svg xmlns:dsvg="http://www.corel.com/schemas/2002/dSV
<script type="text/ecmascript" xlink:href="dsvg11/dSVG.js"/>
<script type="text/ecmascript" xlink:href="dsvg11/baseUI.js"/>
<script type="text/ecmascript" xlink:href="dsvg11/constraint.js"/>
<script type="text/ecmascript" xlink:href="dsvg11/button.js"/>
<script type="text/ecmascript" xlink:href="dsvg11/setData.js"/>
<dsvg:checkBox toggle="true" xlink:href="dsvg11/skinCheckBox_Default.svg#skinC
<dsvg:setData value="Sample of setting data." elementID="checkBoxLabel" id="dsvgUniqueID_8"/>
</dsvg:checkBox>
<text y="80" x="150" fill="green" id="checkBoxLabel">label</text>
<dsvg:checkBox toggle="true" xlink:href="dsvg11/skinCheckBox_Default.svg#skinC
<dsvg:setData value="Sample of setting data." elementID="checkBoxLabel2" id="dsvgUniqueID_9"/>
</dsvg:checkBox>
<text y="130" x="150" fill="green" id="checkBoxLabel2">label</text>
</svg&g t;
http://xpserver.mozdev.org/ xpserver is complicated and not finished, although there is a group in India actively working on it.
From the web site: mod_PX7 then uses XPCOM to load and run the components. The components can be chained using SAX-like events. For example a database component can do a query. The output from the db component is expected to be in XML. This XML can be sent to the browser or fed into another component. For example, an XSLT style sheet. The output from the stylesheet can then go to the browser or be fed into yet another component such as FOP for PDF generation or xmlch to generate a 3D chart using GDChart.
You can think of this as starting with an XML file. The XML file is then transformed by various processes into other intermediate XML files. The final transform may be to SVG, XML, PDF, JPEG, etc. In reality the intermediate files don't exist and the stages are chained together via SAX events.
Transformation stages can be written in XSLT, C or Javascript. Some of the XSLT/Javascript transformation stages were writen to detect browser capabilities, if the browser is capable the stage runs in the browser instead of the server.
If you think about this to the Nth degree, XHTML can be represented via a giant XSLT transform with SVG as output. It would be neat if the W3C spec'ed CSS as transforms on SVG. This would take a lot of the ambiguity out of it.
(No, I didn't forget PNG. It has some technical and ideological advantages, but browser support is still, well, incomplete.)
So what's wrong with SVG plugins? They don't exploit the full power of SVG. It's not just a graphics format, it's an XML application. In other words, it's a markup language, just like HTML. A good XML-aware browser (something both IE and Mozilla pretend to be) shouldn't isolate SVG from the rest of the document.
Consider the gif-filled Slashdot page you're looking at right now. They have gotten rid of a lot of bitmaps (though the left hand clickbar looks slightly less cool as a result). But they still use some weird little bitmaps, plus a lot of weird tables and font kludges that are hard to maintain and tend to be browser dependent.
There's a simple fix: put SVG support in the browser (it is a W3C invention after all) and allow indiscriminate embedding of XHTML and SVG in each other. (Not to mention any other XML applications the browser happens to support.) The Mozilla people know this, but still consider SVG support experimental and non-standard. This has been the status quo for quite some time, and given AOL's abandonment of Gecko, is not likely to change.
Maybe if Mozilla had concentrated on basic technological improvements like this and less on eye-candy and silly features... well, AOL, would probably still have screwed them over. But I might feel bad about it.
KHTML looks to be the new leader in open-source web browsers. And their does seem to be a lot of interest in using the engine to render SVG. Alas, the KDE people still think of SVG as something you embed in something else.
The dSVG code itself is still part of our IP, so unfortunately I can't show it to you (sorry). But if dSVG had instead been implemented natively in the SVG Viewer (which would not have been proper), I don't think most would dispute it's code being unreleased. I should point out, however, that the reason the script is obfuscated is not just to protect IP, it's also because it's actually much faster that way, since the strings are smaller. Really, I was actually quite shocked at just how much faster it is.
As for sample applications built using CSGS, you can find lots of them at www.corel.com/smartgraphics/resources.
In terms of constructs like 'if' and 'elst', I'm not convinced that wrapping the SVG object model in a layer of xml tags will do any more good than wrapping stuff in a layer of xml tags usually does.
However, it's good to see a widget set being produced for SVG. If a powerful, standard widget set evolves that'll be immeasurably useful in promoting SVG and taking advantage of SVGs natural strengths.
Whence? Hence. Whither? Thither.
Reposting this from a previous comment...
It's XML markup, therefore it can be data-mapped and transformed via XSLT.
It's easier for an authoring tool to create markup (which the author can customize) than to create script.
It's more high-level than DOM methods, providing a more direct linkage between the syntax and the intent of the author. So it's more intuitive to non-developers than script, thus allowing designers to create web apps all by themselves.
Because it's markup, it (or something like it) has the potential to become a standard one day and thus become natively implemented. This would allow SVG on small devices to still have excellent interactivity without needing a script engine, which typically takes up half of the footprint (aside from being slow).
Markup is guaranteed to be interoperable on the authoring side, while scripting is not.
The Adobe SVG viewer recently, and surprizingly, had a beta of version 6.0 come out. This can be found here. Of course because the Mozilla folks changed the plug-in mechanisms, it still crashes Mozilla, but this is great news from Adobe as many rumors were that the entire SVG team was canned. Obviously that isn't true, and they continue to develop upon it. Corel, as you obviously know if you read even the summary of this article, has a great viewer out as well, along with a variety of tools for working with SVG.
Of course MSDN Magazine covered SVGs last month. Of course I'm biased given that I wrote that article.
I for one love the idea of being able to develop SVG applications.
While it's true that SVG currently need a plug-in, that its installation base is quite small compared to Flash (but most people installing Adobe Acrobat install the SVG plug-in without even noticing), the SVG specification is a W3 Standard, and it's easier to integrate with other Open Source tools on the server side.
I doubt that dSVG will initially appeal to a large public who won't see the point of it over Flash for multimedia applications, but it certain should appeal to people writing applications for the enterprise where it's easier to control what is installed on the users' machines.
dSVG could be a great cross-platform tool (while the GUI software that build applications runs only under Windows for now, SVG runs on any platform) and could actually be helpful in pushing companies to use SVG as a standard for web applications rather than rely on proprietary formats that are not easy to integrate with Open Source development tools or that will always be a couple of step behind the commercial implementations.
It must also be recognised that while the technology to build really powerful web application is there in IE, Mozilla, Opera and al, there are very few really interactive applications using those technologies, simply because there is not enough compatibility between the various standard implementations, and to work around those is too costly and difficult to manage well.
We end up with web sites that use only the lowest common denominator set of technology, with is not enough to build really powerful applicative environments. So in the end, all those powerful technologies are great showcases, but get barely used in the real world.
While Flash is not going away any time soon (it is likely that it will always remain big in multimedia environments), SVG has more potential for building rich, natural, intuitive and powerful GUIs that easily integrate with existing and well established server technologies, Open Source or not.
I always liked Corel and their tools. I've been a fan of CorelDraw since version 2, and I really like that they are the first one who understand the role that SVG will play in application building.
Adobe is surely the major pusher of the technology, but they haven't yet caught up on that idea that SVG can go way beyond chart applications and pretty graphics.
What was missing was a GUI toolkit, and dSVG is looking good to fill that role, so instead of whining that the tools don't yet work on Linux or that the ULEA is 3km long, let's focus a bit on the question at hand: have a look at the specification and help if we can.
I know I will try because I need these tools, and I think our community is about supporting and encouraging that kind of attitude from commercial companies.
While the Corel guy is using an XML GUI language, this is the Scripting approach that the he has chosen not to use. With the code on the KevLinDev site you can create various SVG widgets, with a call to a javascript function.
I think I'd prefer to do it this way, rather then use XML if I was doing it by hand, as it is closer to normal GUI API's then some verbose XML language. I guess the XML approach would probably be great for the back-end standard for various IDE's
The most interesting thing about the KevLinDev stuff is how some of these javascript calls allow you to provide what the guy calls pSVG, (parametric SVG). pSVG is really just a hack to try and address some of the deficiencies of SVG - hopefully some of these ideas get into the official SVG spec at some stage so you don't have to hack around it like this.
Check out TIBET from Technical Pursuit. It's a full browser application environment, built using JavaScript. They decided on JavaScript, because it's the only language guaranteed to be on the client side. When they were building out the libraries, they found that it was more powerful than they expected. They've actually extended the language, using only the language itself.
Applications have to pull down a large (1 MB plus) set of JavaScript libraries. So this isn't for web applets, or even server-based web applications. (Although it's easy for the code to communicate with the server.) It's meant for full-blown applications that will run completely in the browser.
They also include some application development tools. (I haven't taken a look at those yet.) The whole thing is available under an Open Source license or under a proprietary license if you prefer.
Software sucks. Open Source sucks less.