RIDL

The Relaxer Interface Definition Language (RIDL) is an interface definition language.

interface

The interface is a top-level element of RIDL.

The interface element has these attributes:

• name
• namespace
• java.type

The name attribute specifies a component name. The namespace attribute specifies a namespace for the component. The name and namespace attributes are required attributes.

The interface element has the following child elements:

• grammar
• attribute
• operation
• invariant
• state-machine

The grammar element defines a document type used in the interface. The interface element can have any number of grammar children.

The attribute element defines an attribute RIDL supports. The interface element can have any number of attribute children.

The operation element defines an operation that RIDL supports. The interface element can have any number of operation children.

The invariant element defines an invariant to constrain the state of the component. The interface element can have any number of invariant children.

The state-machine element defines a state machine model. The interface element can have zero or one state-machine element.

Example

List 19.3.1.1.1[grammarInterface.ridl] is a sample RIDL definition.

<interface xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account" name="accountManager">
<grammar namespace="http://example.com/account" \
    location="grammarInterface.rng"/>
  <operation name="findAccount">
    <in name="accountNo" type="token"/>
    <out label="account"/>
  </operation>
</interface>

This RIDL definition has same meaning with an RCDL definition in List 19.3.1.1.2[grammarInterface.rcdl].

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="accountManager">
  <interface namespace="http://example.com/account" name="accountManager">
<grammar namespace="http://example.com/account" \
    location="grammarInterface.rng"/>
    <operation name="findAccount">
      <in name="accountNo" type="token"/>
      <out label="account"/>
    </operation>
  </interface>
</component>

grammar

The grammar element has the following attributes:

• namespace
• location

The namespace attribute specifies a namespace for the grammar. The location attribute specifies a location for the grammar.

Example

List 19.3.2.1.1[grammarGrammar.rcdl] is a sample RCDL definition and List 19.3.2.1.2[grammarGrammar.rng] is a sample RELAX NG schema used in the RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="accountManager">
  <interface namespace="http://example.com/account" name="accountManager">
<grammar namespace="http://example.com/account" \
    location="grammarGrammar.rng"/>
    <operation name="findAccount">
      <in name="accountNo" type="token"/>
      <out label="account"/>
    </operation>
  </interface>
</component>

<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <start>
    <ref name="account"/>
  </start>
  <define name="account">
    <element name="account">
      <attribute name="accountNo">
        <data type="token"/>
      </attribute>
      <element name="balance">
        <data type="int"/>
      </element>
      <element name="owner">
        <data type="token"/>
      </element>
      <ref name="address"/>
      <zeroOrMore>
        <ref name="phone"/>
      </zeroOrMore>
    </element>
  </define>
  <define name="address">
    <element name="address">
      <attribute name="zip">
        <data type="token"/>
      </attribute>
      <text/>
    </element>
  </define>
  <define name="phone">
    <element name="phone">
      <attribute name="area">
        <data type="token"/>
      </attribute>
      <data type="token"/>
    </element>
  </define>
</grammar>

attribute (type)

The attribute element defines an attribute for an interface.

There are two ways you can use the attribute element. One way is the attribute element to specify a type. Another way is the attribute element to specify a label. This section addresses the attribute element to specify a type. It has attributes as follows:

• name
• mode
• access
• default
• type
• java.type

The name attribute defines a name for the attribute. The name attribute is required.

The mode attribute defines an access mode of the attribute. Available values are read-only, read-write, and write-only. The mode attribute is optional. Default value is read-write.

The access attribute defines the visibility of the attribute. Available values are public, protected, and private. The access attribute is optional. Default value is public.

The default attribute defines a default value. The default attribute is optional.

The type attribute defines type name. The type attribute is required.

The java.type attribute defines a Java type or class name to be used in the implementation. The java.type attribute is optional.

The attribute attribute also can have an element as follows:

• facet

The facet element defines a constraint against the value of the attribute.

Example

List 19.3.3.1.1[grammarAttributeType.rcdl] is a sample RCDL definition and List 19.3.3.1.2[grammarAttributeType.rng] is a sample RELAX NG schema to be used in the sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="backOffice">
  <interface namespace="http://example.com/account" name="accountManager">
    <grammar namespace="http://example.com/account"
             location="grammarAttributeType.rng"/>
    <attribute name="numberOfAccounts" type="long"
               access="public" mode="read-write"/>
    <operation name="findAccount">
      <in name="accountNo" type="token"/>
      <out label="account"/>
    </operation>
  </interface>
</component>

<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <start>
    <ref name="account"/>
  </start>
  <define name="account">
    <element name="account">
      <attribute name="accountNo">
        <data type="token"/>
      </attribute>
      <element name="balance">
        <data type="int"/>
      </element>
      <element name="owner">
        <data type="token"/>
      </element>
      <ref name="address"/>
      <zeroOrMore>
        <ref name="phone"/>
      </zeroOrMore>
    </element>
  </define>
  <define name="address">
    <element name="address">
      <attribute name="zip">
        <data type="token"/>
      </attribute>
      <text/>
    </element>
  </define>
  <define name="phone">
    <element name="phone">
      <attribute name="area">
        <data type="token"/>
      </attribute>
      <data type="token"/>
    </element>
  </define>
</grammar>

List 19.3.3.1.3[IAccountManager.java] is a generated interface from the RCDL defition by Relaxer.

import java.rmi.*;

public interface IAccountManager extends Remote {
    /**
     * Application interface of the operation findAccount.
     *
     * @param accountNo
     * @exception RemoteException
     * @return Account
     */
    Account findAccount(String accountNo) throws RemoteException;

    /**
     * @param numberOfAccounts
     * @exception RemoteException
     */
    void setNumberOfAccounts(long numberOfAccounts) throws RemoteException;

    /**
     * @exception RemoteException
     * @return long
     */
    long getNumberOfAccounts() throws RemoteException;
}

attribute (label)

The attribute element can also define a label, in addition to a type.

There are two kind of the attribute elements. One is the attribute element to specify a type. Another one is the attribute element to specify a label. This section addresses the attribute element to specify a label. It has attributes as follows:

• name
• mode
• access
• label
• java.type

The name attribute defines a name. The name attribute is required.

The mode attribute defines access mode. Available values are read-only, read-write, and write-only. The mode attribute is optional. Default value is read-write.

The access attribute defines the visibility of the attribute element. Available values are public, protected, and private. The access attribute is optional. Default value is public.

The label attribute defines label name. The label attribute is required.

The java.type attribute defines a Java type or class name to be used in the implementation. The java.type attribute is optional.

Example

List 19.3.4.1.1[grammarAttributeLabel.rcdl] is a sample RCDL definition and List 19.3.4.1.2[grammarAttributeLabel.rng] is a sample RELAX NG schema to be used in the sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="backOffice">
  <interface namespace="http://example.com/account" name="accountManager">
    <grammar namespace="http://example.com/account"
             location="grammarAttributeLabel.rng"/>
    <attribute name="latestAccount" label="account"
               access="public" model="read-only"/>
    <operation name="findAccount">
      <in name="accountNo" type="token"/>
      <out label="account"/>
    </operation>
  </interface>
</component>

<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <start>
    <ref name="account"/>
  </start>
  <define name="account">
    <element name="account">
      <attribute name="accountNo">
        <data type="token"/>
      </attribute>
      <element name="balance">
        <data type="int"/>
      </element>
      <element name="owner">
        <data type="token"/>
      </element>
      <ref name="address"/>
      <zeroOrMore>
        <ref name="phone"/>
      </zeroOrMore>
    </element>
  </define>
  <define name="address">
    <element name="address">
      <attribute name="zip">
        <data type="token"/>
      </attribute>
      <text/>
    </element>
  </define>
  <define name="phone">
    <element name="phone">
      <attribute name="area">
        <data type="token"/>
      </attribute>
      <data type="token"/>
    </element>
  </define>
</grammar>

List 19.3.4.1.3[IAccountManager.java] is a generated interface from the RCDL defition by Relaxer.

import java.rmi.*;

public interface IAccountManager extends Remote {
    /**
     * Application interface of the operation findAccount.
     *
     * @param accountNo
     * @exception RemoteException
     * @return Account
     */
    Account findAccount(String accountNo) throws RemoteException;
}

operation

The operation element defines an operation of an interface.

The operation has the following attributes:

• name
• query

The name attribute is a required. It specifies an operation name.

The query attribute specifies whether or not an operation has query semantics. This means that the execution of the operation makes no side effects on the state of a component instance. The query attribute is optional. Defa value is false.

The operation element has these elements:

• documentation
• in
• out
• preCondition
• postCondition

The documentation element defines a description for the operation. The documentation element is optional.

The in element defines an input parameter for the operation. Required number of the in elements can be used.

The out element defines an output for the operation. The out element is optional.

The preCondition element defines a pre-condition for the operation. The preCondition is optional.

The postCondition element defines a post-condition for the operation. The postCondition is optional.

Example

List 19.3.5.1.1[grammarOperation.rcdl] is a sample RCDL definition and List 19.3.5.1.2[grammarOperation.rng] is a sample RELAX NG schema to be used in the sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="backOffice">
  <interface namespace="http://example.com/account" name="accountManager">
    <grammar namespace="http://example.com/account"
             location="grammarOperation.rng"/>
    <operation name="findAccount">
      <in name="accountNo" type="token"/>
      <out label="account"/>
    </operation>
  </interface>
</component>

<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <start>
    <ref name="account"/>
  </start>
  <define name="account">
    <element name="account">
      <attribute name="accountNo">
        <data type="token"/>
      </attribute>
      <element name="balance">
        <data type="int"/>
      </element>
      <element name="owner">
        <data type="token"/>
      </element>
      <ref name="address"/>
      <zeroOrMore>
        <ref name="phone"/>
      </zeroOrMore>
    </element>
  </define>
  <define name="address">
    <element name="address">
      <attribute name="zip">
        <data type="token"/>
      </attribute>
      <text/>
    </element>
  </define>
  <define name="phone">
    <element name="phone">
      <attribute name="area">
        <data type="token"/>
      </attribute>
      <data type="token"/>
    </element>
  </define>
</grammar>

invariant

The invariant element defines an invariant constraint for the interface or the component.

• constraint expression

Example

List 19.3.6.1.1[grammarInvariant.rcdl] is a sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/calc"
           name="backOffice">
  <interface namespace="http://example.com/calc" name="calc">
    <attribute name="nOperation" type="int"/>
    <operation name="plus">
      <in name="lhs" type="int"/>
      <in name="rhs" type="int"/>
      <out type="int"/>
    </operation>
    <invariant>
      <greaterEqualThan>
        <attribute name="nOperation"/>
        <value>0</value>
      </greaterEqualThan>
    </invariant>
  </interface>
</component>

When you use relaxer with -cdl.filer.assert switch, a filter for assertion, CalcAssertionFilter shown in List 19.3.6.1.2[CalcAssertionFilter.java], is generated. This filter checks the condition defined by the invariant element before and after method execution.

import java.rmi.RemoteException;
import org.relaxer.runtime.*;

public class CalcAssertionFilter extends AbstractCalcFilter {

    /**
     * @param master
     */
    public CalcAssertionFilter(Object master) {
        super(master);
    }

    /**
     * Asserts against operation plus$Calc.
     *
     * @param lhs
     * @param rhs
     * @exception RemoteException
     * @return int
     */
    public int plus$Calc(int lhs, int rhs) throws RemoteException {
        ICalcFilter $reference$ = rGetReference$Calc();
        RVerifyReport $report$ = new RVerifyReport();
        RVerifyContext $context$ = new RVerifyContext();
        String $message$;
        try {
            rAssertInvariants();
            $message$ = $context$.isValid(lhs, "int");
            if ($message$ != null) {
$report$.addError("lhs", RVerifyReport.INVALID_VALUE, lhs, "int", \
    $message$);
            }
            $message$ = $context$.isValid(rhs, "int");
            if ($message$ != null) {
$report$.addError("rhs", RVerifyReport.INVALID_VALUE, rhs, "int", \
    $message$);
            }
            if (!$report$.isValid()) {
                throw (new IllegalArgumentException());
            }
            int $result$ = $reference$.plus$Calc(lhs, rhs);
            rAssertInvariants();
            $message$ = $context$.isValid($result$, "int");
            if ($message$ != null) {
$report$.addError("$result$", RVerifyReport.INVALID_VALUE, $result$, "int", \
    $message$);
            }
            if (!$report$.isValid()) {
                throw (new RAssertionException($report$));
            }
            return ($result$);
        } catch (RemoteException e) {
            throw (e);
        } catch (Exception e) {
            if (e instanceof RAssertionException) {
                throw ((RAssertionException)e);
            } else {
                throw (new RemoteException(e.getMessage(), e));
            }
        }
    }

    /**
     * Invariant
     *
     * @exception RemoteException
     * @return boolean
     */
    public boolean rIsValidInvariants() throws RemoteException {
        ICalcFilter $reference$ = rGetReference$Calc();
        return (($reference$.getNOperation$Calc() >= 0));
    }

    /**
     * Invariant
     *
     * @exception RemoteException
     */
    public void rAssertInvariants() throws RemoteException {
        if (!(rIsValidInvariants())) {
            throw (new RAssertionException("invariant"));
        }
    }
}

preCondition

The preCondition element defines a pre-condition constraint of the operation.

• constraint expression

Example

List 19.3.7.1.1[grammarPreCondition.rcdl] is a sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/calc"
           name="backOffice">
  <interface namespace="http://example.com/calc" name="calc">
    <attribute name="nOperation" type="int"/>
    <operation name="plus">
      <in name="lhs" type="int"/>
      <in name="rhs" type="int"/>
      <out type="int"/>
      <preCondition>
        <greaterEqualThan>
          <attribute name="nOperation"/>
          <value>0</value>
        </greaterEqualThan>
      </preCondition>
    </operation>
  </interface>
</component>

When you use relaxer with -cdl.filer.assert switch, a filter for assertion, CalcAssertionFilter shown in List 19.3.7.1.2[CalcAssertionFilter.java], is generated. This filter checks the condition defined by the preCondition element before and after method execution.

import java.rmi.RemoteException;
import org.relaxer.runtime.*;

public class CalcAssertionFilter extends AbstractCalcFilter {

    /**
     * @param master
     */
    public CalcAssertionFilter(Object master) {
        super(master);
    }

    /**
     * Asserts against operation plus$Calc.
     *
     * @param lhs
     * @param rhs
     * @exception RemoteException
     * @return int
     */
    public int plus$Calc(int lhs, int rhs) throws RemoteException {
        ICalcFilter $reference$ = rGetReference$Calc();
        RVerifyReport $report$ = new RVerifyReport();
        RVerifyContext $context$ = new RVerifyContext();
        String $message$;
        try {
            rAssertInvariants();
            $message$ = $context$.isValid(lhs, "int");
            if ($message$ != null) {
$report$.addError("lhs", RVerifyReport.INVALID_VALUE, lhs, "int", \
    $message$);
            }
            $message$ = $context$.isValid(rhs, "int");
            if ($message$ != null) {
$report$.addError("rhs", RVerifyReport.INVALID_VALUE, rhs, "int", \
    $message$);
            }
            if (!$report$.isValid()) {
                throw (new IllegalArgumentException());
            }
            if (!($reference$.getNOperation$Calc() >= 0)) {
                throw (new IllegalStateException("pre-condition"));
            }
            int $result$ = $reference$.plus$Calc(lhs, rhs);
            rAssertInvariants();
            $message$ = $context$.isValid($result$, "int");
            if ($message$ != null) {
$report$.addError("$result$", RVerifyReport.INVALID_VALUE, $result$, "int", \
    $message$);
            }
            if (!$report$.isValid()) {
                throw (new RAssertionException($report$));
            }
            return ($result$);
        } catch (RemoteException e) {
            throw (e);
        } catch (Exception e) {
            if (e instanceof RAssertionException) {
                throw ((RAssertionException)e);
            } else {
                throw (new RemoteException(e.getMessage(), e));
            }
        }
    }

    /**
     * Invariant
     *
     * @exception RemoteException
     * @return boolean
     */
    public boolean rIsValidInvariants() throws RemoteException {
        ICalcFilter $reference$ = rGetReference$Calc();
        return (true);
    }

    /**
     * Invariant
     *
     * @exception RemoteException
     */
    public void rAssertInvariants() throws RemoteException {
        if (!(rIsValidInvariants())) {
            throw (new RAssertionException("invariant"));
        }
    }
}

postCondition

The postCondition element defines a post-condition constraint of the operation.

• constraint expression

Example

List 19.3.8.1.1[grammarPostCondition.rcdl] is a sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/calc"
           name="backOffice">
  <interface namespace="http://example.com/calc" name="calc">
    <attribute name="nOperation" type="int"/>
    <operation name="plus">
      <in name="lhs" type="int"/>
      <in name="rhs" type="int"/>
      <out type="int"/>
      <postCondition>
        <greaterEqualThan>
          <attribute name="nOperation"/>
          <value>0</value>
        </greaterEqualThan>
      </postCondition>
    </operation>
  </interface>
</component>

When you use relaxer with -cdl.filer.assert switch, a filter for assertion, CalcAssertionFilter shown in List 19.3.8.1.2[CalcAssertionFilter.java], is generated. This filter checks the condition defined by the postCondition element before and after method execution.

import java.rmi.RemoteException;
import org.relaxer.runtime.*;

public class CalcAssertionFilter extends AbstractCalcFilter {

    /**
     * @param master
     */
    public CalcAssertionFilter(Object master) {
        super(master);
    }

    /**
     * Asserts against operation plus$Calc.
     *
     * @param lhs
     * @param rhs
     * @exception RemoteException
     * @return int
     */
    public int plus$Calc(int lhs, int rhs) throws RemoteException {
        ICalcFilter $reference$ = rGetReference$Calc();
        RVerifyReport $report$ = new RVerifyReport();
        RVerifyContext $context$ = new RVerifyContext();
        String $message$;
        try {
            rAssertInvariants();
            $message$ = $context$.isValid(lhs, "int");
            if ($message$ != null) {
$report$.addError("lhs", RVerifyReport.INVALID_VALUE, lhs, "int", \
    $message$);
            }
            $message$ = $context$.isValid(rhs, "int");
            if ($message$ != null) {
$report$.addError("rhs", RVerifyReport.INVALID_VALUE, rhs, "int", \
    $message$);
            }
            if (!$report$.isValid()) {
                throw (new IllegalArgumentException());
            }
            int $result$ = $reference$.plus$Calc(lhs, rhs);
            rAssertInvariants();
            $message$ = $context$.isValid($result$, "int");
            if ($message$ != null) {
$report$.addError("$result$", RVerifyReport.INVALID_VALUE, $result$, "int", \
    $message$);
            }
            if (!$report$.isValid()) {
                throw (new RAssertionException($report$));
            }
            if (!($reference$.getNOperation$Calc() >= 0)) {
                throw (new RAssertionException("post-condition"));
            }
            return ($result$);
        } catch (RemoteException e) {
            throw (e);
        } catch (Exception e) {
            if (e instanceof RAssertionException) {
                throw ((RAssertionException)e);
            } else {
                throw (new RemoteException(e.getMessage(), e));
            }
        }
    }

    /**
     * Invariant
     *
     * @exception RemoteException
     * @return boolean
     */
    public boolean rIsValidInvariants() throws RemoteException {
        ICalcFilter $reference$ = rGetReference$Calc();
        return (true);
    }

    /**
     * Invariant
     *
     * @exception RemoteException
     */
    public void rAssertInvariants() throws RemoteException {
        if (!(rIsValidInvariants())) {
            throw (new RAssertionException("invariant"));
        }
    }
}

in (type)

There are two kind of in elements. One type is in element to specify a type. Another one type is in element to specify a label. This section addresses the in element to specify a type.

The in element for type has attributes as follows:

• name
• type
• java.type

The name attribute defines a name of the attribute. The name attribute is required.

The type attribute specifies a XML type of the attribute. The type attribute is required.

The java.type attribute specifies a Java type of the attribute. The java.type attribute is optional.

Example

List 19.3.9.1.1[grammarInType.rcdl] is a sample RCDL definition and List 19.3.9.1.2[grammarInType.rng] is a sample RELAX NG schema to be used in the sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="backOffice">
  <interface namespace="http://example.com/account" name="accountManager">
    <grammar namespace="http://example.com/account"
             location="grammarInType.rng"/>
    <operation name="findAccount">
      <in name="accountNo" type="token"/>
      <out label="account"/>
    </operation>
  </interface>
</component>

<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <start>
    <ref name="account"/>
  </start>
  <define name="account">
    <element name="account">
      <attribute name="accountNo">
        <data type="token"/>
      </attribute>
      <element name="balance">
        <data type="int"/>
      </element>
      <element name="owner">
        <data type="token"/>
      </element>
      <ref name="address"/>
      <zeroOrMore>
        <ref name="phone"/>
      </zeroOrMore>
    </element>
  </define>
  <define name="address">
    <element name="address">
      <attribute name="zip">
        <data type="token"/>
      </attribute>
      <text/>
    </element>
  </define>
  <define name="phone">
    <element name="phone">
      <attribute name="area">
        <data type="token"/>
      </attribute>
      <data type="token"/>
    </element>
  </define>
</grammar>

in (label)

There are two kind of in elements. One kind is the in element to specify type. Another one is the in element to specify label. This section addresses the in element to specify label.

The in element for label has attributes as follows:

• name
• namespace
• label
• java.type

The name attribute defines a name of the attribute. The name attribute is required.

The namespace attribute specifies a namespace of the attribute. The namespace attribute is optional.

The label attribute specifies a RELAX label of the attribute. The label attribute is required.

The java.type attribute specifies a Java type of the attribute. The java.type attribute is optional.

Example

List 19.3.10.1.1[grammarInLabel.rcdl] is a sample RCDL definition and List 19.3.10.1.2[grammarInLabel.rng] is a sample RELAX NG schema to be used in the sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="backOffice">
  <interface namespace="http://example.com/account" name="accountManager">
    <grammar namespace="http://example.com/account"
             location="grammarInLabel.rng"/>
    <operation name="setAccount">
      <in name="account" label="account"/>
    </operation>
  </interface>
</component>

<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <start>
    <ref name="account"/>
  </start>
  <define name="account">
    <element name="account">
      <attribute name="accountNo">
        <data type="token"/>
      </attribute>
      <element name="balance">
        <data type="int"/>
      </element>
      <element name="owner">
        <data type="token"/>
      </element>
      <ref name="address"/>
      <zeroOrMore>
        <ref name="phone"/>
      </zeroOrMore>
    </element>
  </define>
  <define name="address">
    <element name="address">
      <attribute name="zip">
        <data type="token"/>
      </attribute>
      <text/>
    </element>
  </define>
  <define name="phone">
    <element name="phone">
      <attribute name="area">
        <data type="token"/>
      </attribute>
      <data type="token"/>
    </element>
  </define>
</grammar>

out (type)

There are two kind of out elements. One kind is the out element to specify a type. Another one is the out element to specify a label. This section addresses the out element to spacify a type.

The out element for type has the following attributes:

• name
• type
• java.type

The name attribute defines a name of the attribute. The name attribute is required.

The type attribute specifies a XML type of the attribute. The type attribute is required.

The java.type attribute specifies a Java type of the attribute. The java.type attribute is optional.

Example

List 19.3.11.1.1[grammarOut.rcdl] is a sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="backOffice">
  <interface namespace="http://example.com/account" name="accountManager">
    <operation name="getNumberOfAccounts">
      <out type="int"/>
    </operation>
  </interface>
</component>

out (label)

There are two kind of the out elements. One is the out element to specify a type. Another one is the out element to specify a label. This section addresses the out element to specify a label.

The out element for label has attributes as follows:

• name
• namespace
• label
• java.type

The name attribute defines a name of the attribute. The name attribute is required.

The namespace attribute specifies a namespace of the attribute. The namespace attribute is optional.

The label attribute specifies a RELAX label of the attribute. The label attribute is required.

The java.type attribute specifies a Java type of the attribute. The java.type attribute is optional.

Example

List 19.3.12.1.1[grammarOutLabel.rcdl] is a sample RCDL definition and List 19.3.12.1.2[grammarOutLabel.rng] is a sample RELAX NG schema to be used in the sample RCDL definition.

<component xmlns="http://www.relaxer.org/xmlns/cdl"
           namespace="http://example.com/account"
           name="backOffice">
  <interface namespace="http://example.com/account" name="accountManager">
    <grammar namespace="http://example.com/account"
             location="grammarOutLabel.rng"/>
    <operation name="findAccount">
      <in name="accountNo" type="token"/>
      <out label="account"/>
    </operation>
  </interface>
</component>

<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <start>
    <ref name="account"/>
  </start>
  <define name="account">
    <element name="account">
      <attribute name="accountNo">
        <data type="token"/>
      </attribute>
      <element name="balance">
        <data type="int"/>
      </element>
      <element name="owner">
        <data type="token"/>
      </element>
      <ref name="address"/>
      <zeroOrMore>
        <ref name="phone"/>
      </zeroOrMore>
    </element>
  </define>
  <define name="address">
    <element name="address">
      <attribute name="zip">
        <data type="token"/>
      </attribute>
      <text/>
    </element>
  </define>
  <define name="phone">
    <element name="phone">
      <attribute name="area">
        <data type="token"/>
      </attribute>
      <data type="token"/>
    </element>
  </define>
</grammar>