[Laszlo-dev] <datapath> isn't allowed on the canvas

[Henry Minsky]

Oh, I don't think we've ever done that. I guess you could stop the
instantiator from running, but that might be more confusing to the
user than doing nothing, unless
some explanatory message were printed to the debugger.

LzInstantiator.halt() for example

On 11/6/07, Philip Romanik <promanik at laszlosystems.com> wrote:
>
>  Detecting and displaying an error message isn't hard. However, there are a
> lot of downstream errors. What is the best way to stop the application from
> running?
>
>  Thanks!
>
>  Phil
>
>
>
>
> Hmm, in lps 3.4, the schema says it's permitted, but it also crashes there.
>  I think we ought to fix it so it doesn't crash at least.
>
>  The schema currently allows this because datapath is a subclass of
> datapointer, and datapointer is allowed at the top level of canvas.
>
>  <interface name="canvas" extends="Instance">
>    <containsElements>
>      <element>view</element>
>      <element>script</element>
>      <element>stylesheet</element>
>      <element>audio</element>
>      <element>resource</element>
>      <element>font</element>
>      <element>datasource</element>
>      <element>datapointer</element>
>      <element>dataset</element>
>  ....
>
>
>  The schema description language I wrote (an extension of the <interface>
> declaration syntax) currently doesn't have any way to say that a child class
> is allowed (e.g., datapointer), but one of its subclasses
>  (datapointer) is forbidden.
>
>
>
>
>
>  On 11/6/07, Philip Romanik < promanik at laszlosystems.com> wrote:
>  >
>  >  Somebody with more knowledge about data handling should make this
>  > call. I think it's an error because it will crash swf if defined at
> top-level.
>  >
>  >
>  >
>  >
>  > Would you like it to generate  a warning, or compiler error?
>  >
>  >  On 11/6/07, Philip Romanik < promanik at laszlosystems.com > wrote:
>  >  > Hi Henry,
>  >  >
>  >  > This bug,
>  > http://jira.openlaszlo.org/jira/browse/LPP-3767, is  >
> generated
>  > because a user can create a <datapath> tag on the canvas.
>  >  > Is it possible to fix this in the schema?
>  >  > A datapath isn't allowed on the canvas. The test case come from
> LPP-2089:
>  >  >
>  >  >
>  >  > <canvas>
>  >  >      <dataset name="test">
>  >  >          <item>first</item>
>  >  >          <item>second</item>
>  >  >      </dataset>
>  >  >
>  >  >      <datapath id="dp" xpath="test:/item"/>
>  >  >      <handler name="oninit">
>  >  >         Debug.write(dp);
>  >  >      </handler>
>  >  > </canvas>
>  >  >
>  >  >
>  >  > This crashes swf, and generates errors in dhtml. If this can't be
>  > > handled by the schema, I'll handle it in the LFC.
>  >  >
>  >  > Thanks!
>  >  >
>  >  > Phil
>  >  >
>  >  >
>  >
>  >
>  >  --
>  >  Henry Minsky
>  >  Software Architect
>  >  hminsky at laszlosystems.com
>
>
>  --
>  Henry Minsky
>  Software Architect
>  hminsky at laszlosystems.com


-- 
Henry Minsky
Software Architect
hminsky at laszlosystems.com