Rick J's point:
> 3) The content of an element is the text that a dumb browser that is not
> aware of your document type will display it. Therefore the text
> should be in the nature of an alternative string for guidance. So
> <caption> should be content, and <left> etc should use attributes.
made a lot of sense for me. I think, however, that John G's application of XML
is such that the properties of objects 'are' the content, and therefore it's not required
for other viewers to skip that information.
I would like to hear some pro's & con's about the following four styles
(continuing John Gossman's example):
1 Attributes within element
<button top=20 left=20 bottom=40 right=100>
<caption>Click me!</caption>
</button>
2 Attributes as single specific sub-element
<button>
<region top=20 left=20 bottom=40 right=100 />
<caption>Click me!</caption>
</button>
3 Attributes as several specific sub-elements
NOTE: the properties of the button are stored as in style 1 (i.e. within the element) so
other viewers can skip them.
<button>
<top value=20/>
<left value=20/>
<bottom value=40/>
<right value=100/>
<caption>Click me!</caption>
</button>
4 Attributes as several generic sub-elements
NOTE: The properties of the button are stored as content, since the document is
intented to be storage for objects & their properties (i.e. the properties 'are' the content).
<button>
<prop name="top">20</prop>
<prop name="left">20</prop>
<prop name="bottom">40</prop>
<prop name="right">100</prop>
<caption>Click me!</caption>
</button>
In addition I have two questions about elements and attributes.
1. Generic tag with 'type' attribute
When should you use a generic <object type="button"> versus a specific <button>:
generic:
<object type="button>
Click this!
</object>
specific:
<button>
Click this!
</button>
2. Attributes as sub-element(s)
When should you move attributes to a sub-element:
as attributes:
<button top=20 left=20 bottom=40 right=100>
</button>
as sub-element:
<button>
<region top=20 left=20 bottom=40 right=100 />
</button>