I'm looking at an auto-generated XSD and I noticed that there are quite a few types that are repeated & so am looking to minimize repetition. When I write my own XSDs I normally do it the way its done for the Option1 attribute in the code below, however this XSD does it the way that the Option2 attribute is done.
<xs:element name="baseElement">
<xs:complexType>
<xs:attribute name="Option1" type="NonEmptyString" />
<xs:attribute name="Option2">
<xs:simpleType>
<xs:restriction base="NonEmptyString" />
</xs:simpleType>
</xs:attribute>
</xs:complexType>
</xs:element>
<xs:simpleType name="NonEmptyString">
<xs:restriction base="xs:string">
<xs:minLength value="1"/>
</xs:restriction>
</xs:simpleType>
So I was wondering, is there a difference between these two methods & if not which is better practice? I would be more inclined to use Option1 as it makes the overall file shorter easier to manage
Related
I am developing an XSD document to validate XML Import files. Nearly all elements of the import file 'can' have an ID attribute (UPDATE). The UPDATE attribute must be limited to 4 possible values, so I have this pre-set type to use for the attribute restriction...
<xs:simpleType name="MyUpDir">
<xs:restriction base="xs:string">
<xs:enumeration value="OVERWRITE"/>
<xs:enumeration value="ADDONLY" />
<xs:enumeration value="NOERASE" />
<xs:enumeration value="IGNORE" />
</xs:restriction>
</xs:simpleType>
In addition to the attribute restrictions, each element's value is limited by a variety of pre-set custom types
Example:
<xs:simpleType name="MyChar50">
<xs:restriction base="xs:string">
<xs:maxLength value="50" />
</xs:restriction>
</xs:simpleType>
To combine the two, I know I can do it in-line for each element as follows:
<xs:element name="FullName">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="MyChar50">
<xs:attribute name="UPDATE" type="MyUpDir" />
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
The problem is that there are over 1000 elements in the import file, each having varying length/regEx/precision restrictions (roughly 20 custom types) as well as have the potential for the UPDATE attribute. Without the UPDATE attribute, I could do each element on its own line by using the custom types, greatly reducing the 'content' portion of the XSD. But from what I've read, it appears that to accomodate the custom types AND the potential for the attribute mentioned, I'm forced to use the expanded sample (last example) instead of being able to retain a single line for each such element. Is there not a way to minimize this further by creating a custom type that combines the two?
I would think that you could do 20 custom types more (for a total of 40) and then use the appropriate ones (w/ or w/o attribute). In your case:
<xs:complexType name="MyChar50Attr"><!-- This one has attributes -->
<xs:simpleContent>
<xs:extension base="MyChar50">
<xs:attribute name="UPDATE" type="MyUpDir"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:element name="FullName" type="MyChar50Attr"/>
I need to make sure I have 2 instances of an element, one with each attribute.
Essentially I need both:
/*:SalesPersonParty/*:PartyID[#schemeAgencyName="SalesPersonID"]
AND
/*:SalesPersonParty/*:PartyID[#schemeAgencyName="SalesPersonPduID"]
I have cardinality 2..2 but 2 instances of either attribute is valid. I need one of each and order doesn't matter.
Here are the relevant schema components:
<xs:simpleType name="RestrictedString">
<xs:restriction base="xs:string">
<xs:pattern value="([0-9]{3})|([0-9]{10})" />
</xs:restriction>
</xs:simpleType>
<xs:element name="SalesPersonParty" minOccurs="2" maxOccurs="2">
<xs:complexType>
<xs:sequence>
<xs:element name="PartyID" minOccurs="1" maxOccurs="1">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="star:RestrictedString">
<xs:attribute name="schemeAgencyName" use="required">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="SalesPersonID" />
<xs:enumeration value="SalesPersonPduID" />
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
Is this even possible?
Thanks and regards,
Tony
I think you can do it with a uniqueness constraint. You'll have to know the container element for SalesPersonParty element; call it Transaction. Then you need something like:
<xs:element name="Transaction">
...
<xs:unique name="uniqueAgencyNameConstraint">
<xs:selector xpath="SalesPersonParty/PartyID">
<xs:field xpath="#schemeAgencyName"/>
</xs:unique>
</xs:element>
This says that each SalesPersonParty/PartyID must have a unique schemeAgencyName. Combined with the constraints of having exactly two SalesPersonParty elements and only two possible values in the enumeration, all values must occur once.
I'm trying to define an element type in XSD, for which i want an optional attribute, which if present can either contain a float, or be empty (but still present).
i.e:
<xs:element name="MyElement">
<xs:complexType>
<xs:attribute name="optionalFloatAttribute" type="xs:float" use="optional"/>
</xs:complexType>
</xs:element>
Needs "fixing" to allow all of the following xml:-
<MyElement/>
or
<MyElement optionalFloatAttribute=""/>
or
<MyElement optionalFloatAttribute="3.14159"/>
The only way I can see of doing this is to change type to xs:string, and use xs:restriction with a regular expression. But this doesn't seem very ideal to me. Is there a better way?
And I have to be able to support these variations of the xml - the program and existing xml is legacy, and I am trying to back-create a schema to match the myriad variations I see in what we have to regard as valid xml.
You can define custom type for that by combining float and empty string:
<xs:element name="MyElement">
<xs:complexType>
<xs:attribute name="optionalFloatAttribute" type="emptyFloat" use="optional"/>
</xs:complexType>
</xs:element>
<xs:simpleType name="emptyFloat">
<xs:union>
<xs:simpleType>
<xs:restriction base='xs:string'>
<xs:length value="0"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType>
<xs:restriction base='xs:float'>
</xs:restriction>
</xs:simpleType>
</xs:union>
</xs:simpleType>
Or using regExp:
<xs:simpleType name="emptyFloat">
<xs:restriction base="xs:string">
<xs:pattern value="-?\d*\.?\d*"/>
</xs:restriction>
</xs:simpleType>
If you could stand using an element rather than an attribute you could make the xs:float nillable. This way you can use the xsi:nil="true" in your instance document to indicate that the element has no value:
<!-- definition -->
<xs:element name="quantity" type="xs:float" nillable="true" />
<!-- instance -->
<quantity xsi:nil="true" />
No equivalent for attributes though.
I don't think there's a way to handle this and use xs:float. Fundamentally it comes down to the fact that empty string isn't a valid number. You'd either normally expect a value of 0, or for the element to be missing altogether. There's a good explanation as the answer to the following question:
Empty elements for primitve datatypes forbidden in XSD
It seems that the option of using xs:string and a regexp might be your best plan.
Is this the proper way to set an attribute with enumerated values on the complexType AvailStatusMessageType. I see a lot of examples that declare a complexContent section right below the complexType declaration? What is this complexContent for and is it necessary here?
<xs:complexType name="AvailStatusMessageType">
<xs:sequence>
<xs:element name="LengthsOfStay" type="LengthsOfStayType" />
<xs:element name="RestrictionStatus" type="RestrictionStatusType"/>
</xs:sequence>
<xs:attribute name="BookingLimit">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="SetLimit" />
<xs:enumeration value="AdjustLimit"/>
<xs:enumeration value="RemoveLimit"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:complexType>
Element types can be divided into two categories in XML Schemas
Elements that can contain structural markup (attributes or child elements)
Elements that contain only textual markup
Further, the elements that contain markup (group 1) can be again divided to two groups
Elements that are allowed to have child elements
Elements that are not allowed to have child elements
First division separates (1) <complexType> and (2) <simpleType>. Second one separates (1) <complexContent> and (2) <simpleContent>.
<xs:complexContent> is not usually seen, because it is an implicit default so the whole structure can be abbreviated by omitting that element. This common structure
<xs:complexType>
... (<xs:sequence> or anything) ...
</xs:complexType>
is actually identical to
<xs:complexType>
<xs:complexContent>
<xs:restriction base="xs:anyType">
... (<xs:sequence> or anything) ...
</xs:restriction>
</xs:complexContent>
</xs:complexType>
In your structure an element with type "AvailStatusMessageType" 1) contains markup 2) and has child elements. So your structure is a complex type with complex content. Your example seems correct even though you haven't used the <xs:complexContent> element, because you are actually using the abbreviated form. It is identical to this:
<xs:complexType name="AvailStatusMessageType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="LengthsOfStay" type="LengthsOfStayType" />
<xs:element name="RestrictionStatus" type="RestrictionStatusType"/>
</xs:sequence>
<xs:attribute name="BookingLimit">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="SetLimit" />
<xs:enumeration value="AdjustLimit"/>
<xs:enumeration value="RemoveLimit"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
A complex type may have simple or complex content. You would use <simpleContent> if you were defining a complex type with simple content. You must use the <complexContent> element when you are restricting or extending another complex type (because you specify the base type as an attribute in the <complexContent> element). If you are simply creating a complex type (with complex content), as you are doing, you may use (but are not required to use) the <complexContent> element.
Your enumeration looks right.
I'm trying to write a xml schema that will validate this piece of xml:
<date isodate="2007-03-14">14 march 2007</date>
The attribute isodate should have it's type set to xs:date and the content should be max 50 characters long.
I wonder if it's possible to write the xml schema definition in one block, something like this maybe:
<xs:element name="date" minOccurs="0" maxOccurs="1">
<xs:complexType>
<xs:simpleContent>
<xs:restriction base="xs:string">
<xs:minLength value="0"/>
<xs:maxLength value="50"/>
</xs:restriction>
<xs:attribute name="isodate" type="xs:date" use="required"/>
</xs:simpleContent>
</xs:complexType>
</xs:element>
The code above doesn't work, and I can't really figure out why. Only workaround I have found is to break out the restriction part into a separate type, and link that like this:
<xs:simpleType name="reviewDate">
<xs:restriction base="xs:string">
<xs:minLength value="0"/>
<xs:maxLength value="50"/>
</xs:restriction>
</xs:simpleType>
<xs:element name="date" minOccurs="0" maxOccurs="1">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="reviewDate">
<xs:attribute name="isodate" type="xs:date" use="required"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
The question I have is how to write the definition in one block so that the schema is a bit more readable, and doesn't reference types in other parts of the schema.
You cannot merge both a restriction and an extension into one block of XSD. The solution that you have with the "ReviewDate" simple type is the best solution I know of.
Marc
You can have a element with restriction and attribute(-s).
The key is to define custom type with it's restrictions and then using it add attributes to it.
Refer here: Content restriction and attribute validation on the same element in XSD