XML schema regular expressions question and recommended XML Schema book

[Fred Smith]

Any suggestions or tips to the questions below I have been wrestling with would be most welcome:

I have an example XSD file I have been experimenting with. Suppose a user can select from 1 to 4 checkboxes on a web form:

Select your favorite sport(s):

(checkbox) baseball
(checkbox) football
(checkbox) soccer
(checkbox) golf

Futhermore, suppose a user selects all the above sports:
The xml generated from the program that reads the form variables would be:

<sport>baseball\n\football\n\soccer\n\golf</sport>

Questions:

1. what is the most effective schema statement to handle the possiblity of the user selecting either baseball or baseball and football or baseball, football, soccer etc..? In other words, any permutation of checkboxes.

I would think you would use the logical or operator (|). I was thinking something like below, but I am getting errors such as "Datatype error: In element 'sport': Value ........ does not match regular expression facet ................

<xsd:simpleType name="sport">
<xsd:restriction base="xsd:string">
<xsdattern value="baseball\\n|\\nfootball\\n|\\nsoccer\\n|golf"/>

2. Does anyone recommend any books that explain XML Schema Regular Expressions with some good examples? I have read Definitive XML Schema, by Walmsley.

Thanks for any tips on the above,

Fred

 

[Martin Honnen]

Any suggestions or tips to the questions below I have been wrestling with would be most welcome:

I have an example XSD file I have been experimenting with. Suppose a user can select from 1 to 4 checkboxes on a web form:

Select your favorite sport(s):

(checkbox) baseball
(checkbox) football
(checkbox) soccer
(checkbox) golf

Futhermore, suppose a user selects all the above sports:
The xml generated from the program that reads the form variables would be:

<sport>baseball\n\football\n\soccer\n\golf</sport>

Questions:

1. what is the most effective schema statement to handle the possiblity of the user selecting either baseball or baseball and football or baseball, football, soccer etc..? In other words, any permutation of checkboxes.

I would think you would use the logical or operator (|). I was thinking something like below, but I am getting errors such as "Datatype error: In element 'sport': Value ........ does not match regular expression facet ................

<xsd:simpleType name="sport">
<xsd:restriction base="xsd:string">
<xsdattern value="baseball\\n|\\nfootball\\n|\\nsoccer\\n|golf"/>

If there are certain fixed values possible a list of an enumerated type could help:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="root">
<xs:complexType>
<xs:sequence>
<xs:element ref="sport" maxOccurs="unbounded" />
</xs:sequence>
</xs:complexType>
</xs:element>

<xs:simpleType name="sport">
<xs:restriction base="xs:string">
<xs:enumeration value="baseball" />
<xs:enumeration value="football" />
<xs:enumeration value="soccer" />
<xs:enumeration value="golf" />
</xs:restriction>
</xs:simpleType>

<xs:element name="sport">
<xs:simpleType>
<xs:list itemType="sport" />
</xs:simpleType>
</xs:element>

</xs:schema>

That allows values like

<?xml version="1.0" encoding="UTF-8"?>
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="test20040205Xsd.xml"> <sport>baseball football soccer golf</sport> <sport>baseball football soccer golf </sport> <sport>soccer football</sport> </root>

meaning the order is not restricted to what you have.

If you want to use a regular expression to restrict the type I think the following helps:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="root">
<xs:complexType>
<xs:sequence>
<xs:element ref="sport" maxOccurs="unbounded" />
</xs:sequence>
</xs:complexType>
</xs:element>

<xs:element name="sport">
<xs:simpleType>
<xs:restriction base="xs:string">
<xsattern
value="(baseball\s*)?(football\s*)?(soccer\s*)?(golf)?" /> </xs:restriction> </xs:simpleType> </xs:element>

</xs:schema>

which restricts the content of a <sport> element to being zero or one occurrence of baseball plus some whitespace and zero or one occurence of football plus some whitespace and zero or one occurence of soccer plus some whitespace plus zero or one occurence of golf.