1. Introducing Turbine 7

This chapter introduces the main ideas behind Turbine 7 and how it works, and provides some common usage scenarios.

• What is ASP.NET Turbine?
• How does ASP Turbine Work?
• A Simple Example
• Output Formats
• Templates
• Data and Media Integration
• Building User Interfaces with Flash Components
• Turbine Window

 

What is ASP.NET Turbine?

ASP.NET Turbine 7 generates Flash rich media and Adobe PDF documents from ASP.NET scripts. Turbine allows you to generate nedia with content obtained from a variety of sources like image, video, XML documents, databases, other Flash movies, plain text files, etc.

Turbine is an integrator of dynamic content into rich media, allowing a clean separation between Presentation from Content. With ASP.NET Turbine 7 you can build whole new rich media applications - fully live content multimedia sites!
Turbine is based on a sophisticated media-independent architecture that allows output to media formats like Flash, PDF, SVG and image formats*.

Turbine can be seen as in this diagram:

ASP.NET Turbine 7 includes the following capabilities:

• Includes a comprehensive .NET scripting interface
• Easy to use Turbine Media Markup Language that can express all the rich media capabilities: text, images, shapes, movie clips, buttons, scripting, video and audio
• Full Flash MX support with extensive component integration
• Can dynamically generate Flash movies - the Turbine architecture also allows generation to other media types, like SVG or image (not included)
• Can dynamically generate Adobe PDF documents
• Extensive data integration capabilities - from XML, ADO.NET DataSets, DataTables or DataViews or plain old text files, local or remote
• Dynamic Chart generation for Flash and PDF - chart types can be customized and new types created
• Sophisticated text capabilities like text flow areas coupled with HTML-like formatting
• Includes images from a variety of formats, from local or remote locations
• Integrates video from AVI, QuickTime, FLV and Animated GIFs in Flash movies
• Integrates MP3, WAV and FLV audio for streaming or event sound generation in Flash movies
• Includes on-the-fly Action Script (ECMA-262 Script or JavaScript) compiler for Flash movies
• Can generate media to local files - allowing for batch automation
• Auto-generation of the HTML media plug-in page
• Server output media caching
• Show template errors immediately on the generated media - allowing for easier and faster development cycles
• Optimizes generated media sizes
• Encrypts PDF documents allowing permissions to be specified
• Embeds fonts used in the PDF document

*  SVG and image output to be available later on the Turbine product line as separate plug-ins. The PDF plug-in is already available

How does ASP.NET Turbine Work?

Turbine works at the server-side, where data can be more flexibly accessed and integrated on media templates. The following steps are usually involved when using Turbine:

1) A web browser user requests an ASP.NET script where Turbine runs
2) The web server runs the ASP.NET script which will create a Turbine object
3) The ASP.NET script and/or Turbine access databases, text, image, video or audio content from any available data sources, either local or remote HTTP locations
4) The fetched content is integrated in Flash or XML media templates
5) A Flash movie is generated and sent to the web browser. Alternatively a PDF document is generated and sent to the web browser.

Turbine's approach represents a performance advantage because the ASP.NET script that does the content access also generates the media, avoiding multiple server accesses, and thus improving web server response times.
Since Turbine runs on the server-side, data access is much easier and faster, content integration with a variety of media types and formats, most of which are not supported by Flash, are possible and straightforward.

A Simple Example

Let's see a basic example - we'll create a Flash movie that will serve as our template, into which we'll insert a message with the current date. First we'll create the Flash .swf movie - open the Flash Editor and get a new, blank movie (File > New). Somewhere on your movie insert a Text Block (static or dynamic) like this:

Current Time is: {text}

After this, save the movie for example with the name time.fla (File > Save) and then Publish into a .swf file (File > Publish) - it will be saved as time.swf - copy this file (or save it directly) into a directory where ASP.NET scripts can be executed.

Then, on the chosen directory we create a file named time.aspx and edit it with any text editor, to include this script, in C#:

Be careful to have the starting <% as the first characters on your ASP file - no spaces, new-lines or other characters should be insert before this or between these blocks. The final %> must also be the last characters on your script, so that no more characters are included.

Now request the time.aspx script through your web browser and you will get a Flash movie with the time information obtained in the ASP.NET script integrated into the Flash .swf template - a Flash movie such as this will appear:

We could also use a template file written in an XML language named Turbine Media Markup Language (MML for short), which we'll see later.

We could also generate a PDF document based on the same code - the only difference would be the GeneratePDF command instead of the GenerateFlash command.

This simple example integrates text into Flash templates - imagine what can be done with images, audio and video, Flash components, database content...

Output Formats

Turbine is multi-media and multi-format: It generates Rich Media Flash, PDF and other formats from common XML, image, video and audio sources. Turbine can "mix" text, image, audio and video, outputting the result to the most appropriate and convenient media format. For instance, when dealing with video, audio and animation, the most convenient output media would be Flash, but when the emphasis is readability and security, then the preferred output format would be PDF.

The next list describes which features are specific and available for each output format supported by Turbine:

Macromedia Flash format :

• Supports audio, video, images, text and shapes
• Supports sophisticated transparencies and gradients
• Supports multimedia interactivity
• Supports client side scripting
• Supports compressed images, audio and video, as well as a global file compression
• Supports content streaming
• Doesn't support encryption and document permissions

Adobe PDF format:

• Supports text with font embedding and subsetting
• Supports images and shapes
• Supports compressed images, as well as a global file compression
• Supports encryption and document permissions
• Doesn't support transparency and gradients
• Doesn't support audio and video
• Doesn't support client side scripting

In general, text-based, printable content is more suited for PDF, while Flash is better suited for interactive multi-media content.

 
Templates

Turbine can use two types of templates where text, audio and visual media can be integrated:

• Common Flash .swf movies generated by the Macromedia Flash authoring tool or any other third party .swf authoring tools like Adobe's Live Motion or Swish (although for Flash components, the Macromedia authoring tool must be used).
  By using visual editors one can enter the Turbine variables or commands in the exact place and instant, simplifying content integration with Flash rich media capabilities.
• XML templates can be used on situations where the flexibility and format-independence provided by XML is preferable. Templates can be specified in the powerful Turbine Media Markup Language (TMML or MML for short). Although on this case visual media authoring is not available, one can take advantage of all the benefits associated with XML.

On some scenarios using visual templates is clearly advisable, for example if the content is to be integrated on complex movies, with several scenes, transitions or animation. On other scenarios, the simplicity and openness of XML documents can be preferred.
And there are also scenarios where a mix of Flash and MML would be even better - in fact this is also supported - MML commands can be issued inside Flash .swf templates in a dynamic or input Text Fields - when the Flash template is loaded, these MML commands will be executed in the middle of the Flash .swf template. As we'll see, MML tags are pervasive and can be used in a number of different places, inside the Turbine engine.

Data and Media Integration

Turbine includes advanced data and media (image, audio, video) integration capabilities. Data can be integrated into templates from the following sources:

• Database data sources like .NET DataSets, DataTables or DataViews
• Text Files from local or remote HTTP locations
• Variable=value formatted text files from local or remote HTTP locations
• XML files, local or remote
• Any data available to ASP.NET scripting

The following types of media can be loaded:

• Images in PNG, GIF, BMP, TIF and JPEG formats, from local files or remote HTTP locations
• Audio in MP3, WAV or FLV formats, local and remote
• Video in AVI, QuickTime MOV, FLV and Animated GIF formats, local or remote

All these different data and media types can be combined and composed together, to create rich media experiences.

Building User Interfaces with Flash Components

Flash MX introduced Flash components - reusable elements that simplify user interface development in Flash media. Turbine 7 includes powerful component support - components can be included and displayed where appropriated (either in a Flash editor or on MML) and filled with any data accessible to your script.

For example - let's see how to display and fill a list box - on the Flash editor, create an empty Flash movie and drag'n'drop a ListBox component, from the Components panel (Flash UI Components area). Set its instance name to (for example) "list". Then Save, for example as listbox.fla and then Publish to listbox.swf. Next, create an ASP.NET script with this content, on the same directory :

After requesting this script in a browser, we get a ListBox component, filled with the values created on the script:

This way, presentation and data can be cleanly kept separated - presentation on the Flash .swf template (for which we could also have used a MML template), while data is handled by the ASP.NET script (we could have fetched data from many other sources - database queries, XML, files, other HTTP queries).

Please note that Flash components are not rendered nor work when exporting to Adobe PDF.

The Turbine Window

As a fact of life, during the development process, errors inevitably occur - Turbine communicates errors in two ways:

• ASP.NET Scripting errors are displayed on the normal .NET way, in an HTML page that the web server sends to the browser.
• Template errors on Flash or MML files are displayed right in the generated Flash movie, inside the Turbine Window - which is a window that appears on the generated movies with error and warning messages related with template problems. When generating to PDF, these errors and warning messages will appear in red on the top of the page. All the tag errors are listed with the offending line number, for easier and faster problem detection.
  Besides displaying errors, the Turbine Window can also be used as a Trace window and a mini-debugger (for variable watching). The Turbine window looks like this:
  The Turbine Window is transparent and appears above the generated movie. In Flash 6+ movies, the last window location is automatically recorded and reused. You can see this in action on the above Flash movie: move the window and refresh the page, it will appear where you left it.
  The button immediately to the right of the window title allows you to display the contents of the last selected variable or object - for example type _root in the Turbine Window, then select the word _root with the cursor and click on that button - it will display the variables and objects available inside the _root object.