What are best practices for designing XML schemas? [closed]

Answer 1

I've found the attribute form more manageable when dealing with Cartesian coordinates. My projects tend to require multiple namespaces, and sharing the coordinate type definition between namespaces gets ugly in the sub-element form. In the sub-element form, you have to either qualify the sub-elements, juggle namespaces on the base or root element, or default to unqualified element names (i.e. namespace hiding)

Answer 2

See the tutorial:

• "XML Schemas: Best Practices" by Roger Costello.

I also recommend:

• Priscilla Walmsley's book "Definitive XML Schema".

• Jeni Tennison's XML Schema pages

Answer 3

XML is somewhat subjective in terms of design - I don't think there are exact guidelines for how the elements and attributes should be laid out, but I tend to go with using elements to represent 'things' and attributes to represent singular attributes/properties of them.

In terms of the coordinates example either would be perfectly acceptable, but my inclination would be to go with <coordinate x="" y=""/> because it is somewhat more terse, and makes the document a little more readable if you have many of them.

The most important thing, though, is the namespace of the schema. Make sure that (a) you have one, and (b) you have a version in there so you can change things in the future and issue a new version. Versions may be either dates or numbers, e.g.

http://company.com/2008/12/something/somethingelse/
urn:company-com:2008-12:something:somethingelse

http://company.com/v1/something/somethingelse/
urn:company-com:v1:something:somethingelse

Answer 4

Here is a great list of methods for designing an XML grammar.

As stated above it is a subjective practice, but this site gives some useful directions, such as “use this pattern to solve problem X”…or “advantages and disadvantages are…”.

Answer 5

I guess, it depends on how complex or simple the structure is.
I will make x and y as attribute, unless x and y have their own details

You can look at HTML or any other form of markup, which is used to define things (XAML in case of WPF, MXML in case of flash) to understand, why something is chosen as attribute as against a child node)

if x and y are not to be repeated, they can be attributes.

Lets say co-ordinates has multiple x and y, I guess xml doesnt allow multiple attributes with same name for a node. In that case, you will have to use child nodes.

Answer 6

Look at the relationships of the data you are trying to represent is the best approach that I've found.