Re: [xml-dev] generate common xml shema from multiple xml instances

[Mukul Gandhi <gandhi.mukul@gmail.com>]

I further see following issues with the usefulness of XML to XSD
conversion tools.

1) Suppose a following element exists in the XML document.

<color>RED</color>

How would the "XML to Schema" conversion tool guess, that the element
"color" represents a "visual attribute of things" and generate a
simple type declaration like below:

<xs:simpleType name="Color">
  <xs:restriction base="xs:string">
    <xs:enumeration value="RED" />
    <xs:enumeration value="GREEN" />
    <xs:enumeration value="YELLOW" />
  </xs:restriction>
</xs:simpleType>

Which the Schema author may want to do.

In the abscence of this semantic intelligence, the Schema generation
tool may generate a Schema declaration like following:

<xs:element name="color" type="xs:string" />

2) It may be difficult for the tool to reuse type definitions. In case
of structural similarities in a large XML document, or a set of XML
documents, the tool may generate lot of Schema types, which the Schema
author may like to refactor.

Though I believe, the XML to Schema conversion tools may be useful to
quickly generate a Schema, which could be further enahanced and
refactored by the Schema author.

On Wed, Jun 17, 2009 at 11:33 AM, Mukul Gandhi<gandhi.mukul@gmail.com> wrote:
> Hi,
>   If you are looking to build such a utility yourself, you need to
> consider few points, like mentioned below:
>
> Let's say your instance document is following (i.e., having two
> "person" elements):
>
> <people>
>  <person>..</person>
>  <person>..</person>
> </people>
>
> You need to decide for example:
>
> 1) What value of occurrence indicator, you want to have? Do you need
> the value "unbounded" or want it to be a specific number?
>
> for e.g.,
>
> <xs:element name="person" type="Person" maxOccurs="unbounded" />
>
> OR
>
> <xs:element name="person" type="Person" maxOccurs="10" />
>
> 2) Should the complex type "Person" be a named type or an anonymous type?
>
> Inferring the XSD structure in an automated way from multiple XML
> files, could be inaccurate.
>
> I believe, you need some amount of manual adjustment of the XSD, even
> if it's generated by some tool.
>
> On Wed, Jun 17, 2009 at 10:54 AM, Rita Shen<shaledova@gmail.com> wrote:
>> Hi,
>>
>> How can I generate a common XML schema for multiple xml instances??
>> I know many tools can generate an XSD from a single XML instance.
>> But in my case, I want to get the unknown common XSD for a bunch of XML
>> instances.
>>
>> Thanks for any help,
>> syt



-- 
Regards,
Mukul Gandhi