I want to create an XML schema that forces a header followed by any of several items. In other words, this is valid. <header> must always be the first item, but then A and B can be in any order.
<root>
<header/>
<A/>
<B/>
<A/>
<B/>
</root>
My understanding is that I can allow A and B to be in any order with the following.
<xs:element name="root">
<xs:complexType>
<xs:choice maxOccurs="unbounded">
<xs:element ref="A"/>
<xs:element ref="B"/>
</xs:choice>
</xs:complexType>
</xs:element>
But how do I force the first element to be <header>?
Groups can nest in content models, just as parenthesized expressions can nest in regular expressions. At the outer level, you want a header element followed by a mix of A and B elements. So use an xs:sequence to specify that sequence.
<xs:complexType>
<xs:sequence>
<xs:element ref="root"/>
<xs:choice maxOccurs="unbounded">
<xs:element ref="A"/>
<xs:element ref="B"/>
</xs:choice>
</xs:sequence>
</xs:complexType>
Related
I have an Xml file like this:
<Configuration xmlns="http://schemas.benefittech.com/evolution/site">
<SiteSettings>
<ProfileGroup>TBOLoanPmtElection</ProfileGroup>
<AWSGroup>TBOLoanPmtElection_Admin</AWSGroup>
</SiteSettings>
</Configuration>
And I have an XSD file like this:
<?xml version="1.0" encoding="us-ascii" ?>
<xs:schema elementFormDefault="qualified" attributeFormDefault="unqualified" version="5.0"
xmlns="http://schemas.benefittech.com/evolution/site" targetNamespace="http://schemas.benefittech.com/evolution/site"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:vs="http://schemas.benefittech.com/Visual-Studio-Intellisense" vs:friendlyname="Evolution Site Configuration">
<xs:element name="Configuration">
<xs:complexType>
<xs:all>
<xs:element name="SiteSettings" minOccurs="0" maxOccurs="1">
<xs:complexType>
<xs:all>
<xs:element name="AWSGroup" type="xs:string" minOccurs="0" maxOccurs="1"/>
<xs:element name="ProfileGroup" type="xs:string" minOccurs="0" maxOccurs="1"/>
<xs:element name="LogActivityGroup" type="xs:string" minOccurs="0" maxOccurs="1"/>
</xs:all>
</xs:complexType>
</xs:element>
</xs:all>
</xs:complexType>
</xs:element>
</xs:schema>
I want to enable my Xml to look something like the following to allow for 'environment overrides' (the E attribute on the env:* element):
<Configuration xmlns="http://schemas.benefittech.com/evolution/site" xmlns:env="http://schemas.benefittech.com/evolution/siteenvironment">
<SiteSettings>
<ProfileGroup>TBOLoanPmtElection</ProfileGroup>
<AWSGroup>TBOLoanPmtElection_Admin</AWSGroup>
<env:AWSGroup E="SecondEnvironment">TBOLoanPmtElection2_Admin</env:AWSGroup>
</SiteSettings>
</Configuration>
Is there a way to modify the XSD so that given EVERY element in my configuration, I want to optionally have a env:* version of it. Do I have to make a new schema file like below that is basically a duplicate of original except for the target namespace?
<?xml version="1.0" encoding="us-ascii" ?>
<xs:schema elementFormDefault="qualified" attributeFormDefault="unqualified" version="5.0"
xmlns="http://schemas.benefittech.com/evolution/siteenvironment" targetNamespace="http://schemas.benefittech.com/evolution/siteenvironment"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:vs="http://schemas.benefittech.com/Visual-Studio-Intellisense" vs:friendlyname="Evolution Site Configuration">
<xs:element name="Configuration">
<xs:complexType>
<xs:all>
<xs:element name="SiteSettings" minOccurs="0" maxOccurs="1">
<xs:complexType>
<xs:all>
<xs:element name="AWSGroup" type="xs:string" minOccurs="0" maxOccurs="1">
<xs:complexType>
<xs:attribute name="E" use="required" type="xs:string"/>
</xs:complexType>
</xs:element>
<xs:element name="ProfileGroup" type="xs:string" minOccurs="0" maxOccurs="1">
<xs:complexType>
<xs:attribute name="E" use="required" type="xs:string"/>
</xs:complexType>
</xs:element>
<xs:element name="LogActivityGroup" type="xs:string" minOccurs="0" maxOccurs="1">
<xs:complexType>
<xs:attribute name="E" use="required" type="xs:string"/>
</xs:complexType>
</xs:element>
</xs:all>
</xs:complexType>
</xs:element>
</xs:all>
</xs:complexType>
</xs:element>
</xs:schema>
Is there a way to modify the XSD so that given EVERY element in my configuration, I want to optionally have a env:* version of it.
No, there is no elegant way to add, after each element, an optional element having the same name but a different namespace. You would need to add each such env:* element individually.
Do I have to make a new schema file like below that is basically a duplicate of original except for the target namespace?
Yes, but only if you stick to this plan of using a different namespace for the 'extension' elements. In your reply to my comment you said
I thought I'd need separate namespaces. I didn't want to change code everywhere that selects elements. For example, SiteConfig.Elements( "SiteSettings" ).Elements( "AWSGroup" ).FirstOrDefault(); Would continue to work without picking up the env:* elements. Then during the publish process, I would swap out the env:* properties everywhere and code would just work. What's your suggestion?
I've hardly written a line of C#, but according to https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.firstordefault?view=netcore-3.1 the FirstOrDefault() method returns the first element in the sequence or a default. So I think there is a much simpler approach that will not break the existing code...
On each element that needs to have option extension element(s):
Set maxOccurs="unbounded" (or "2", if you only want to allow one extension element)
Add the attribute "E" and make it optional (so that existing documents which omit it on the first occurrence are still valid).
The name "E" for the attribute is not ideal - I would pick something more descriptive if possible.
I have the following XSD structure:
<xs:schema xmlns:ns="http://abc/">
...
<xs:element name="abc">
<xs:complexType>
<xs:sequence>
<xs:element ref="map"/>
</xs:sequence>
</xs:complexType>
</xs:element>
...
<xs:element name="map">
<xs:complexType>
<xs:sequence>
<xs:element name="entry" type="ns:MapEntryType" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:unique name="entry">
<xs:selector xpath="entry"/>
<xs:field xpath="key"/>
</xs:unique>
</xs:element>
<xs:complexType name="MapEntryType">
<xs:sequence>
<xs:element name="key" type="xs:string"/>
<xs:element name="value" type="xs:anyType"/>
</xs:sequence>
</xs:complexType>
</xs:schema>
This is doing its job.
The map element now has to be called something different based on whichever is the wrapper, so the name is sometimes map, sometimes properties, sometimes options, etc.
Therefore I want to genericize the map element.
I tried doing the following:
Making map a xs:complexType and changing ref to type.
This resulted in xs:unique not being accepted and failed
Making map a xs:complexType, changing ref to type and moving the xs:unique constraint to the element definitions.
This worked but resulted in the XSD having a lot of xs:unique present in the document.
Isn't there a way to simply tell that I want a specific structure and it containing unique elements without having to repeat the unique constraint everywhere?
As Petru Gardea said in his answer
Both XSD 1.0 and 1.1 place the identity constraints under an element
So you have to add xs:unique to every element, but if you are using XSD 1.1 you can define only once a complete xs:unique and then in the rest of the elements use xs:unique ref="name". This is not valid for you as you are using XSD 1.0, but I let it here for future XSD 1.1 users that find this good question.
Example (namespaces removed for clarity):
<xs:element name="map">
<xs:complexType>
<xs:sequence>
<xs:element name="entry" type="MapEntryType" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- Only completely defined once -->
<xs:unique name="uniqueEntry">
<xs:selector xpath="entry"/>
<xs:field xpath="key"/>
</xs:unique>
</xs:element>
<xs:element name="hashMap">
<xs:complexType>
<xs:sequence>
<xs:element name="entry" type="MapEntryType" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- Referenced here and every other time -->
<xs:unique ref="uniqueEntry"/>
</xs:element>
Short answer, it is not possible. Both XSD 1.0 and 1.1 place the identity constraints under an element; a constraint cannot be globally defined, therefore there is no "reuse" per se, other than that of the enclosing element. Given your scenario (different element names for different needs) it is not possible to reuse.
What I'm trying to do is, declare an parent element called "data", which are having 10 sub element of these one element are conditional.
My XSD is:
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:vc="http://www.w3.org/2007/XMLSchema-versioning" elementFormDefault="qualified" attributeFormDefault="unqualified" vc:minVersion="1.1">
<xs:element name="data" >
<xs:complexType>
<xs:sequence>
<xs:element name="sub_data" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:all >
<xs:element ref="A"/>
<xs:element ref="B" minOccurs="0" maxOccurs="1"/>
<xs:element ref="C"/>
<xs:element ref="D"/>
<xs:element ref="E"/>
<xs:element ref="F"/>
<xs:element ref="G"/>
<xs:element ref="H"/>
<xs:element ref="I"/>
<xs:element ref="J"/>
<xs:element ref="K"/>
<xs:element ref="L"/>
<xs:element ref="M"/>
<xs:element ref="N"/>
<xs:element ref="element_group"/>
</xs:all>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="status"/>
</xs:complexType>
</xs:element>
<xs:element name="O" type="xs:string" substitutionGroup="element_group">
<xs:element name="P" type="xs:string" substitutionGroup="element_group">
<xs:element name="Q" type="xs:string" substitutionGroup="element_group">
</xs:schema>
Requirement is:
All element from A to N are appearing in any order.
Element P,Q and R is also part of data but only one element appear from among 3. Order is also any.
More important I have cover 1st and 2nd point but I want one more restriction is that only and only four element will be become the part of <data> that means element count from <A> to <Q> is exact four,
Combination can any of them from <A> to <Q> but final count is only four, please help me.
Now currently i am unable to set maxOccures in <all> , it not compiling the xsd after setting maxOccures.
The simplest way to handle this is probably to use XSD 1.1 and use an assertion on the parent to specify that there must be exactly (or at most) four children. You will also need to make each child of the all-group optional, since thirteen of them will not appear.
The best way might be to redesign your XML to work better with your schema language instead of fighting it. It's hard to give advice on that, though, since your example is abstract enough to make it unclear why you are imposing the requirements you mention.
please assist, this is what i want to achieve in validating my xml file:
<?xml version="1.0" encoding="UTF-8"?>
<worker>
<name>dingo</name>
<ssn>12345</ssn>
</worker>
I want to ensure that the two simple elements 'name' and 'ssn' either have values (as a group) or do not have any value (as a group). They cannot exist individually with a value.
I have to use an XSD schema, so cannot use other options i see suggestions sometimes: Relax NG etc.
I looked into creating a group for elements 'name' and 'ssn' but i am unable to find out how to create a restriction for this group to obtain my condition.
My current XSD file:
<xs:complexType name="worker">
<xs:sequence>
<xs:element name="name" type="xs:string" minOccurs="0" "maxOccurs="1">
<xs:element name="ssn" type="xs:positiveInteger" minOccurs="0" "maxOccurs="1">
</xs:sequence>
</xs:complexType>
<xs:complexType name="worker">
<xs:sequence minOccurs="0">
<xs:element name="name" type="xs:string">
<xs:element name="ssn" type="xs:positiveInteger">
</xs:sequence>
</xs:complexType>
You have to do
<xs:complexType name="worker">
<xs:group ref="workerGrp" minOccurs="0"/>
</xs:complexType>
<xs:group name="workerGrp">
<xs:sequence>
<xs:element name="name" type="xs:string">
<xs:element name="ssn" type="xs:positiveInteger">
</xs:sequence>
</xs:group>
What is the difference between an xs:group and an xs:sequence in XML Schema? When would you use one or the other?
xs:sequence - together with xs:choice and xs:all - is used to define the valid sequences of XML element in the target XML. E.g. the schema for this XML:
<mainElement>
<firstSubElement/>
<subElementA/>
<subElementB/>
</mainElement>
is something like:
<xs:element name='mainElement'>
<xs:complexType>
<xs:sequence>
<xs:element name="firstSubElement"/>
<xs:element name="subElementA"/>
<xs:element name="subElementB"/>
</xs:sequence>
</xs:complexType>
</xs:element>
xs:group is used to define a named group of XML element following certain rules that can then be referenced in different parts of the schema. For example if the XML is:
<root>
<mainElementA>
<firstSubElement/>
<subElementA/>
<subElementB/>
</mainElementA>
<mainElementB>
<otherSubElement/>
<subElementA/>
<subElementB/>
</mainElementB>
</root>
you can define a group for the common sub-elements:
<xs:group name="subElements">
<xs:sequence>
<xs:element name="subElementA"/>
<xs:element name="subElementB"/>
</xs:sequence>
</xs:group>
and then use it:
<xs:element name="mainElementA">
<xs:complexType>
<xs:sequence>
<xs:element name="firstSubElement"/>
<xs:group ref="subElements"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="mainElementB">
<xs:complexType>
<xs:sequence>
<xs:element name="otherSubElement"/>
<xs:group ref="subElements"/>
</xs:sequence>
</xs:complexType>
</xs:element>