RE: Re[2]: [cgmo-webcgm] Question: object onload param

[Lofton Henderson <lofton@rockynet.com>]

[...Replying to Stuart and Dieter together...]

At 03:34 PM 12/9/2005 -0800, Galt, Stuart A wrote:
>When I read 3.4:
>    The user supplies the name of an event handler that the viewer
>    shall invoke upon the 'onload' event. This param element and
>    handler allows for script writers to manipulate the WebCGM
>    DOM at the point at which the user agent has fully parsed
>    the object tag and its descendants and is ready to render
>    the object to the screen.
>
>I interpret it to imply that the browser has interpreted the HTML
>tags, and has passed the OBJECT tag and the PARAMs to the plugin.
>I think the "and is ready to render" implies that the plugin has
>formed a mental image of what it wants to paint onto the display
>but hasn't yet (e.g. The CGM is parsed and loaded, the XCF is parsed
>and loaded, and then the script is called... then it gets painted
>on the display)

I agree with Stuart's reading, which was more careful than mine.  Looking 
again, I think it answers the question I asked -- "load" does NOT include 
render.  Therefore the application has pre-render access to the DOM tree of 
a metafile, and multiple definitions (thru DOM) of the .src attribute are 
possible.

>The changing every time the src changes confuses me.  I am not sure
>why a src change would not want to reload/redraw.

The ability to change the accessed and displayed metafile by redefining the 
.src attribute would allow, for example, a programmatic way to process 
multiple metafiles in succession.  Whether or not this is an important use 
case ... I'll leave that question to the users.

At 12:06 PM 12/10/2005 +0100, Dieter  Weidenbrück wrote:
>[...]
>Rationale:
>WebCGM is in no way tied into an ActiveX implementation, or anything
>similar that requires an OBJECT tag. [...]
>So I vote for the event to be generated once and everytime a WebCGM file
>is loaded and ready for display.

I agree.

-Lofton.