Re: supporting multiple style classes, here is what I am thinking. I had
suggested the following in my earlier email - it would apply the styles by
dereferencing the page-scoped variable "styles.redButton", which contains a map
of styles:
<PushButton styles="$styles.redButton"/>
Conceptually, this is no different than the way styles are currently applied -
it just gets the style data from a different source:
<PushButton styles="{backgroundColor:'#aa0000', color:'#ffffff'}"/>
<PushButton styles="@red_button.json"/>
In fact, this is already supported - if you have a page variable named "styles"
that contains a map named "redButton", it will work. The solution I am
proposing will simply make it easier to define such structures within the page
(currently, you'd need to do it in code):
<bxml:include bxml:id="styles" src="styles.json"/>
To apply multiple style sets, we could support this:
<PushButton>
<styles>
<bxml:value id="styles.redButton"/>
<bxml:value id="styles.bigFont"/>
</styles>
</PushButton>
The <bxml:value> tags would behave the same as the "$" dereference operator.
They would resolve to the value of the page variable with the given ID. This is
currently being tracked in PIVOT-556.
However, you would also be able to do this:
<PushButton>
<styles>
<bxml:include src="red_button.json"/>
<bxml:include src="big_font.json"/>
</styles>
</PushButton>
which may also be convenient.
Not sure how useful it is, but you could even do this:
<PushButton>
<styles backgroundColor="$styles.redButton.backgroundColor"/>
</PushButton>
The beauty of this approach is that it addresses the primary use cases, is
extremely flexible, and relies entirely on existing functionality - we don't
need to create any new classes or concepts to support named styles,
inheritance, etc.
On Jul 2, 2010, at 9:51 PM, Michael Allman wrote:
> It would be very premature for me to provide a good example. I've barely
> started my first Pivot app. Also, I can say that this can't be done with
> Flex apps either. So I never used it there. Doesn't mean it might not have
> come in handy once or twice... I dunno. It may be practically useless.
> Although I have seen it used many times in html.
>
> This comes back to my earlier post. Why not support a subset of CSS syntax
> itself? It's a very mature spec for styling declarative ui stuff.
>
> Cheers,
>
> Michael
>
>
> On Fri, 2 Jul 2010, Greg Brown wrote:
>
>> I have been thinking about that and I have some ideas. But I would like to
>> understand how often that use case actually comes up. I know CSS supports
>> it, but in practice (in Pivot specifically) I wonder how important it is?
>>
>>
>> On Jul 2, 2010, at 7:30 PM, Michael Allman wrote:
>>
>>> Hi Greg,
>>>
>>> How would one specify multiple named styles for a component element? Like
>>>
>>> <PushButton styles="redButton bigFont"/>
>>>
>>> Cheers,
>>>
>>> Michael
>>>
>>> On Fri, 2 Jul 2010, Greg Brown wrote:
>>>
>>>> Hi all,
>>>>
>>>> I have been thinking about this and I think I have a fairly elegant
>>>> solution that will also significantly extend the capabilities of
>>>> BXMLSerializer. I am thinking of extending the <bxml:include> tag to
>>>> support loading of arbitrary content. Currently, it only supports includes
>>>> of other BXML files, but there is no reason that it couldn't be modified
>>>> to include other types, such as JSON, XML, or even images. All we'd have
>>>> to do is determine an appropriate serializer to use for the include - this
>>>> could be inferred based on file extension or could be specified explicitly
>>>> via a "mimeType" attribute to the include tag. The MIME type-to-serializer
>>>> mappings could be configurable such that an include could literally be
>>>> used to load any type of object.
>>>>
>>>> One application of such an extension would be styling. <bxml:include>
>>>> could be used to load a "stylesheet" - a JSON file containing a "map of
>>>> maps". The format of this file would be identical to the format I had been
>>>> considering for the "named styles" approach - each key/value pair in the
>>>> file would essentially represent a "style class". For example, the
>>>> following JSON file would define a "redButton" class:
>>>>
>>>> { redButton: {
>>>> backgroundColor: "#aa0000",
>>>> color: "#ffffff"
>>>> }
>>>> }
>>>>
>>>> In a BXML document, this file could be included as follows:
>>>>
>>>> <bxml:include bxml:id="styles" src="styles.json"/>
>>>>
>>>> The "redButton" style could then be applied to a button as follows:
>>>>
>>>> <PushButton styles="$styles.redButton"/>
>>>>
>>>> Unlike the previous solution I proposed, this approach would require no
>>>> changes to the Component or Container classes whatsoever. With the
>>>> exception of extending the <bxml:include> tag, it relies entirely on
>>>> existing functionality (and existing BXML syntax, so developers will
>>>> already be familiar with it).
>>>>
>>>> There are obviously other applications as well. Some simple examples:
>>>>
>>>> <TableView>
>>>> <tableData>
>>>> <bxml:include src="table_data.json"/>
>>>> </tableData>
>>>> </TableView>
>>>>
>>>> <TreeView>
>>>> <treeData>
>>>> <bxml:include src="tree_data.xml"/>
>>>> </treeData>
>>>> </TreeView>
>>>>
>>>> One challenge might be how to specify the MIME/serializer mapping for an
>>>> include (we won't want BXMLSerializer to include all possible mappings by
>>>> default). This could be inherited from the parent serializer, but I think
>>>> that a BXML syntax for specifying it in markup is probably a good idea.
>>>>
>>>> Anyway, I think this would be an extremely flexible and useful addition to
>>>> the serializer, and I think it also handles the styling case pretty well.
>>>> Let me know what you think.
>>>>
>>>> G
>>>>
>>>>
>>>> On Jul 2, 2010, at 1:34 PM, Greg Brown wrote:
>>>>
>>>>> FYI, named styles are turning out to be a lot more challenging than I
>>>>> expected. The solution I proposed the other day doesn't work - elements
>>>>> in BXML aren't added to the parent element until the end tag is
>>>>> processed. So, given the following structure:
>>>>>
>>>>> <Window styleClasses="{foo:{...}}">
>>>>> <BoxPane>
>>>>> <PushButton styleClass="foo"/>
>>>>> </BoxPane>
>>>>> </Window>
>>>>>
>>>>> when the styleClass attribute of the PushButton is processed, the BoxPane
>>>>> hasn't yet been added to the Window, so the "foo" style class name
>>>>> resolves to null. :-(
>>>>>
>>>>> I'll keep thinking about it, though. Suggestions are welcome.
>>>>>
>>>>> Thanks,
>>>>> G
>>>>>
>>>>
>>
