I can see something like that working -
<resource name="logo" src="blah.png" force="true" />
If the force attribute is present, it overwrites other declarations of
logo and does *not* emit a warning.
The force attribute could mean both "replaceable" and "suppress warning".
The warning could suggest that the force attribute be used if the user
intends to overwrite in case of conflict.
Resources in libraries could define the force
<library>
<resource name="logo" src="logo.png" force="true" />
</library>
<library>
<resource name="logo" src="logo2.png" force="true" />
</library>
Hrm. Come to think of it, that feels wrong.
Would it be too much of a change if there are two new attributes for
resource - force and replaceable?
@force would be tell the compiler not to emit a warning if this resource
overwrites another.
@replaceable would tell the compiler not to emit a warning if this
resource is overwritten
If these two attributes aren't present the current behavior remains.
So resources in Webtop libraries would look like this -
<library>
<resource name="logo" src="logo.png" replaceable="true" />
</library>
-e
Sarah Allen wrote:
That is exactly the dilemma. The tension is between a the frustration
of an accidental override and the frustration if you want to set up
your library to allow customizing a resource, where you have to
provide a resource file and library separately and then the user of
the library needs to create a new resource file and include all your
resources except the logo and include the logo.
I suppose there could be some kind of flag that says that I meant to
override this resource, like:
<resource name="logo" src="logo.png" replace="true"/>
I don't know if that would complicate the implementation or the
language folk would consider it weird, but as a user of the language
it would work for me.
Sarah
On Wed, Aug 29, 2007 at 5:01 AM, Elliot Winard wrote:
I don't know about removing the platform warnings.
If I include two libraries that have resources with conflicting names,
I want to know about it. For example - I might include multiple
libraries , each defining a 'logo' resource and expecting the logo to
be sized a certain way -
<include "mailwindow" />
<include "stockwindow" />
I want the compiler to tell me that the stockwindow's logo is
overwriting the mailwindow's logo. Warnings are informative,
non-fatal and should be used to provide this kind of information.
This proposal skirts CSS altogether. If this gets implemented as
proposed then the display of warnings should be configurable at
compile-time. I think it would be confusing to users if resources (or
classes or instances) get clobbered without any warning.
-e
Sarah Allen wrote:
> I think this is an excellent proposal. cc'ing laszlo-user to see if
> other folks developing in LZX have strong feelings about this ...
>
>
> On Tue, Aug 28, 2007 at 3:12 PM, Bret Simister wrote:
>
>
> Currently, in the OpenLaszlo platform, it was decided that declaring a
> resource twice within an LZX app
> causes a server warning. This was intended to help developers just in
> case they accidentally overrode a
> resource that had already been declared in another library.
>
>
> <!-- the following code produces a warning, but still compiles -->
> <canvas>
> <resource name="logo" src="logo.gif" />
> <resource name="logo" src="logo2.gif" />
>
> <!-- view appears with logo2.gif -->
> <view resource="logo" />
> </canvas>
>
>
>
> At this time, I would suggest that the platform remove these
> warnings and have
> the last resource declaration override all other previous declarations.
>
>
> Here is why...
>
>
> OpenLaszlo now has a CSS implementation. It gives developers an
> elegant method
> of skinning their applications. This works, currently, by first
> declaring a resource
>
>
> <resource name="someimage_rsc" src="somepath/someimage.jpg" />
>
>
> and then referring to that resource in a CSS selector
>
>
> view[name="someview"] {
> resource: someimage_rsc;
> }
>
>
>
>
>
> If a developer builds a library ....
>
>
> myCustomLibrary ( folder )
> library.lzx
> myresources.lzx ( contains many resource definitions including
> 'lowerRightCorner_rsc' )
> mystyles.css ( contains many selectors including one that
> references 'lowerRightCorner_rsc' )
> ... ( other class and source image files )
>
>
> where library.lzx includes both myresources.lzx and mystyles.css
>
> Then library can be used with a simple inclusion in the main app.
>
>
> <canvas>
>
>
> <include name="myCustomLibrary" />
>
>
> <!-- instance of a class from myCustomLibrary -->
> <mycustomclass />
>
>
> </canvas>
>
>
>
>
> Let's assume that " mycustomclass " contains a number of resources,
> and that you ( as a developer )
> only want to change one of those resources . The simplest method to
> accomplish this would be ...
>
>
> <canvas>
>
>
> <include name="myCustomLibrary" />
>
>
> <!-- override resource definition "lowerRightCorner_rsc" defined
> earlier in myresouces.lzx -->
> <resource name="lowerRightCorner"
> src="my_new_path/my_lower_right_corner.jpg" />
>
>
>
> <!-- instance of mycustomclass that will now display
> the new resource based on the unchanged css selector -->
> <mycustomclass />
>
>
> </canvas>
>
>
> Currently, this code would cause a compiler warning. To avoid these
> warnings ( without changing OpenLaszlo ) the resouces.lzx file(s) and
> possibly the library .lzx would have to be edited.
>
>
> If instead, we allow for resource overriding, then ...
>
>
> 1) the original CSS and resource files will remain unchanged
> 2) The old resource for " lowerRightCorner" would NOT be included in
> the app
> 3) There would be clean separation between external libraries and the
> skinning of theses libraries included in an application.
>
>
>
>
>
>
>
>
>
