Projection of Literal Properties to XML Schemas

This section discusses how literal (non-collection) properties are projected to XML types, as well as options that affect the XML schema. It discusses the following:

Default XSD Types for InterSystems IRIS Data Type Classes

If a class or a class property is based on one of the common InterSystems IRIS data type classes, the XML type is set automatically, according to the following table. Classes in the %xsd package map directly to the XML types, as shown in the table.

XML Types for InterSystems IRIS Data Types in the %Library and %xsd Packages

InterSystems IRIS Class in the %xsd Package	InterSystems IRIS Class in the %Library Package	XSD Type Used in Projections to XML
%xsd.anyURIOpens in a new tab		anyURI
%xsd.base64BinaryOpens in a new tab	%BinaryOpens in a new tab %StatusOpens in a new tab	base64Binary
%xsd.booleanOpens in a new tab	%BooleanOpens in a new tab	boolean
%xsd.byteOpens in a new tab	%TinyIntOpens in a new tab	byte
%xsd.dateOpens in a new tab	%DateOpens in a new tab	date
%xsd.dateTimeOpens in a new tab	%PosixTimeOpens in a new tab %StringTimeStampOpens in a new tab %TimeStampOpens in a new tab	dateTime
%xsd.decimalOpens in a new tab	%CurrencyOpens in a new tab %DecimalOpens in a new tab %NumericOpens in a new tab	decimal
%xsd.doubleOpens in a new tab	%DoubleOpens in a new tab	double
%xsd.floatOpens in a new tab		float
%xsd.hexBinaryOpens in a new tab		hexBinary
%xsd.intOpens in a new tab		int
%xsd.integerOpens in a new tab		integer
%xsd.longOpens in a new tab	%BigIntOpens in a new tab %IntegerOpens in a new tab	long
%xsd.negativeIntegerOpens in a new tab		negativeInteger
%xsd.nonNegativeIntegerOpens in a new tab		nonNegativeInteger
%xsd.nonPositiveIntegerOpens in a new tab		nonPositiveInteger
%xsd.positiveIntegerOpens in a new tab		positiveInteger
%xsd.shortOpens in a new tab	%SmallIntOpens in a new tab	short
%xsd.stringOpens in a new tab	%NameOpens in a new tab %StringOpens in a new tab %ListOpens in a new tab	string
%xsd.timeOpens in a new tab	%TimeOpens in a new tab	time
%xsd.unsignedByteOpens in a new tab		unsignedByte
%xsd.unsignedIntOpens in a new tab		unsignedInt
%xsd.unsignedLongOpens in a new tab		unsignedLong
%xsd.unsignedShortOpens in a new tab		unsignedShort

For information on the XML data types, see https://www.w3.org/TR/xmlschema-2/Opens in a new tab.

For example, consider the following class:

Class Schema.DataTypesDemo Extends (%RegisteredObject, %XML.Adaptor)
{

Parameter XMLTYPENAMESPACE="mytypes";

Property binaryprop As %xsd.base64Binary;

Property booleanprop As %Boolean;

Property dateprop As %Date;

Property datetimeprop As %TimeStamp;

Property decimalprop As %Numeric;

Property integerprop As %Integer;

Property stringprop As %String;

Property timeprop As %Time;

}

The schema for this class is as follows:

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:s="http://www.w3.org/2001/XMLSchema" 
elementFormDefault="qualified" targetNamespace="mytypes">
  <complexType name="DataTypesDemo">
    <sequence>
      <element minOccurs="0" name="binaryprop" type="s:base64Binary"/>
      <element minOccurs="0" name="booleanprop" type="s:boolean"/>
      <element minOccurs="0" name="dateprop" type="s:date"/>
      <element minOccurs="0" name="datetimeprop" type="s:dateTime"/>
      <element minOccurs="0" name="decimalprop" type="s:decimal"/>
      <element minOccurs="0" name="integerprop" type="s:long"/>
      <element minOccurs="0" name="stringprop" type="s:string"/>
      <element minOccurs="0" name="timeprop" type="s:time"/>
    </sequence>
  </complexType>
</schema>

Compiler Keywords That Affect the Schema

The Required keyword affects the XML schema, by removing the minOccurs="0" attribute. For example, consider the following class:

Class Schema.PropKeywords Extends (%RegisteredObject, %XML.Adaptor)
{

Parameter XMLTYPENAMESPACE="mytypes";

Property Property1 As %String;

Property Property2 As %String [ Required ];

}

If we generate a schema for the namespace used here, we see the following:

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:s="http://www.w3.org/2001/XMLSchema" 
elementFormDefault="qualified" targetNamespace="test">
  <complexType name="PropKeywords">
    <sequence>
      <element minOccurs="0" name="Property1" type="s:string"/>
      <element name="Property2" type="s:string"/>
    </sequence>
  </complexType>
</schema>

Note that the default for minOccurs is 1; that is, Property2 is required.

Note:

For compatibility reasons, %XML.ReaderOpens in a new tab does not check for required properties by default, but you can cause it to do so; see Checking for Required Elements and Attributes. Also by default, an InterSystems IRIS web service does not check for required properties, but you can cause it to do so; see Checking for Required Elements and Attributes.

No other property keywords affect the schema for data type classes.

Parameters That Affect XML Schemas

The InterSystems IRIS data type classes use many parameters. (For a table that lists the parameters supported in each data type class, see Data Types.) In most cases, you can also specify these as property parameters.

The parameters that affect XML schemas are as follows:

CONTENT

Influences how the property values are escaped; see Handling Special XML Characters.

The "MIXED" value causes a change in the schema, as compared to the other possible values. Consider the following class:

Class Schema.CONTENT Extends (%RegisteredObject, %XML.Adaptor)
{

Parameter XMLTYPENAMESPACE = "mytypes";

Property Property1 As %String;

Property Property2 As %String(CONTENT = "STRING");

Property Property3 As %String(CONTENT = "ESCAPE");

Property Property4 As %String(CONTENT = "MIXED");

}

If we generate a schema for the namespace used here, we see the following:

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:s="http://www.w3.org/2001/XMLSchema" 
elementFormDefault="qualified" targetNamespace="mytypes">
  <complexType name="CONTENT">
    <sequence>
      <element minOccurs="0" name="Property1" type="s:string"/>
      <element minOccurs="0" name="Property2" type="s:string"/>
      <element minOccurs="0" name="Property3" type="s:string"/>
      <element name="Property4">
        <complexType mixed="true">
          <choice maxOccurs="unbounded" minOccurs="0">
            <any processContents="lax"/>
          </choice>
        </complexType>
      </element>
    </sequence>
  </complexType>
</schema>

Notice that the three of these properties have the same type information, because XML treats them in the same way. InterSystems IRIS, however, treats the properties differently as described in Handling Special XML Characters.

If you use the object as input or output for a web method, and SoapBodyUse is encoded for that method, then InterSystems IRIS treats mixed content like string content, the default. That is, if you specify CONTENT as "MIXED", that value is ignored.

DISPLAYLIST

Affects the schema if VALUELIST is also specified and if XMLLISTPARAMETER equal to "DISPLAYLIST". See the discussions for those two parameters.

MAXLEN

Controls the maxLength attribute, which is a facet or restriction. Facets define acceptable values for XML types. The following example shows several of them. Consider the following class:

Class Schema.BasicFacets Extends (%RegisteredObject, %XML.Adaptor)
{

Parameter XMLTYPENAMESPACE = "mytypes";

Property Property1 As %Integer (MINVAL=10, MAXVAL=1000);

Property Property2 As %String (MINLEN=20, MAXLEN=100);

}

If we generate a schema for the namespace used here, we see the following:

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" 
xmlns:s="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" targetNamespace="mytypes">
  <complexType name="BasicFacets">
    <sequence>
      <element minOccurs="0" name="Property1">
        <simpleType>
          <restriction base="s:long">
            <maxInclusive value="1000"/>
            <minInclusive value="10"/>
          </restriction>
        </simpleType>
      </element>
      <element minOccurs="0" name="Property2">
        <simpleType>
          <restriction base="s:string">
            <maxLength value="100"/>
            <minLength value="20"/>
          </restriction>
        </simpleType>
      </element>
    </sequence>
  </complexType>
</schema>

When the SOAP Wizard or the XML Schema Wizard finds a maxLength restriction in a schema, it sets the MAXLEN property parameter as appropriate in the generated class.

MAXVAL

Controls the maxInclusive attribute. See the example in MAXLEN.

MINLEN

Controls the minLength attribute. See the example in MAXLEN.

When the SOAP Wizard or the XML Schema Wizard finds a minLength restriction in a schema, it sets the MINLEN property parameter as appropriate in the generated class.

MINVAL

Controls the minInclusive attribute. See the example in MAXLEN.

VALUELLIST

Adds an <enumeration> restriction to the type. Consider the following class:

Class Schema.VALUELIST Extends (%RegisteredObject, %XML.Adaptor)
{

Parameter XMLTYPENAMESPACE = "mytypes";

Property Property1 As %String;

Property Property2 As %String (VALUELIST = ",r,g,b");

}

The following shows the schema for this class:

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:s="http://www.w3.org/2001/XMLSchema" 
elementFormDefault="qualified" targetNamespace="mytypes">
  <complexType name="VALUELIST">
    <sequence>
      <element minOccurs="0" name="Property1" type="s:string"/>
      <element minOccurs="0" name="Property2">
        <simpleType>
          <restriction base="s:string">
            <enumeration value="r"/>
            <enumeration value="g"/>
            <enumeration value="b"/>
          </restriction>
        </simpleType>
      </element>
    </sequence>
  </complexType>
</schema>

XMLFractionDigits

Applicable to a %NumericOpens in a new tab property. This parameter corresponds to the <fractionDigits> facet, as shown in the following fragment:

<element minOccurs="0" name="Property2">
  <simpleType>
    <restriction base="s:decimal">
      <fractionDigits value="2"/>
      <totalDigits value="5"/>
    </restriction>
  </simpleType>
</element>

XMLTotalDigits

Applicable to a %NumericOpens in a new tab property or an %IntegerOpens in a new tab property. This parameter corresponds to the <totalDigits> facet, as shown in the following fragment:

<element minOccurs="0" name="Property2">
  <simpleType>
    <restriction base="s:decimal">
      <fractionDigits value="2"/>
      <totalDigits value="5"/>
    </restriction>
  </simpleType>
</element>

XMLLISTPARAMETER

Applicable to a %StringOpens in a new tab property that specifies the VALUELIST parameter. Specifies the name of the parameter that contains the list of values to project to XML, instead of the values contained in the object. In most cases, you also specify the standard DISPLAYLIST parameter, and you set XMLLISTPARAMETER equal to "DISPLAYLIST".

The XMLLISTPARAMETER parameter controls the value attribute used in the <enumeration> restriction.

You cannot specify this as a property parameter.

XMLPATTERN

Controls the pattern restriction. Consider the following class:

Class Schema.Pattern Extends (%RegisteredObject, %XML.Adaptor)
{

Parameter XMLTYPENAMESPACE = "mytypes";

Property Property1 As %String;

Property Property2 As %String(XMLPATTERN = "[A-Z]");

}

The schema for this class is as follows:

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:s="http://www.w3.org/2001/XMLSchema" 
elementFormDefault="qualified" targetNamespace="mytypes">
  <complexType name="Pattern">
    <sequence>
      <element minOccurs="0" name="Property1" type="s:string"/>
      <element minOccurs="0" name="Property2">
        <simpleType>
          <restriction base="s:string">
            <pattern value="[A-Z]"/>
          </restriction>
        </simpleType>
      </element>
    </sequence>
  </complexType>
</schema>

If multiple patterns appear in a simple type, then InterSystems IRIS combines the patterns according to https://www.w3.org/TR/xmlschema-2Opens in a new tab (see section 4.3.4.3, Constraints on XML Representation of pattern). The patterns are combined as separate branches in the same pattern (separated by a vertical bar) in the XMLPATTERN parameter.

XSDTYPE

Declares the XSD type used when projecting to XML. This parameter is set appropriately in all InterSystems IRIS data type classes. The InterSystems IRIS XML tools use this parameter when generating schemas. This parameter does not directly affect the input and output transformations, although it should be consistent with them.

Projection of Stream Classes to XML Types

Viewing the Schema for an XML-Enabled Class