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{multi-excerpt-include:Petals-SE-Activity|name=features|nopanel=true}

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{column:width=350px}
{panel:title=Table of contents}{toc:outline=true}{panel}
{panel:title=Contributors}{contributors:order=name|mode=list|showAnonymous=true|showCount=true|showLastTime=true}{panel}
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{section}

h1. Creating a service-unit for a process definition

h2. Creating the service contract


The SE Activity provides a service with several operation for a process definition. A WSDL is associated to this service. This WSDL can be written freely. The user can use its own namespace, its own names, ... It is only constraint by the following rules:
* the operations of the binding section *are annotated* to link them to the supported operations (create an instance of the process definition, complete the current task of the process instance, ...)
* the mandatory parameters of the operation *are annotated* to retrieve the right values.

{tip}For a unit test purpose, an extension of JUnit is available to validate your WSDL not only in a pur WSDL point of view, but also in a SE Activity point of view. See chapter "[Unit testing|#Unit_Testing]".{tip}

h3. Identifying operations

The mapping between operations of the WSDL and operations supported by the SE Activity is declared using a dedicated binding. The binding "Activity" is done adding the element {{\{http://petals.ow2.org/se/activity/1.0}operation}} to the element operation of the binding. Its attribute *{{activityAction}}* defines the operation that will be executed.

h3. Identifying input parameters of operations

In the same way, input parameters of operations are mapped through an annotation placed inside the message of the binding operation. Two natures of input parameters exists: the expected input parameters and variables. Each Activity operation can require mandatory or optional input parameter and can accept to set several variables in the same time.

Input parameters are identified by the annotation adding the element {{\{http://petals.ow2.org/se/activity/1.0}inpu-parameter}}. This annotation takes also two attributes:
* the attribute *{{name}}* defines a name of an expected input parameter of the Activity operation,
* the attribute *{{value}}* defines the value to set to the expected input parameter using an XPath expression.
See operation details to know the expected input parameters.

Variables are identified by the annotation adding the element {{\{http://petals.ow2.org/se/activity/1.0}variable}}. This annotation takes also two attributes:
* the attribute *{{name}}* defines the variable name used in the process definition.
* the attribute *{{value}}* defines the value to set to the variable using an XPath expression.
See operation details to know if variables can be set.
No extra check is done by the SE Activity about the compliance of the variable with the process definition.

{color:red}*TODO. Les types ?; les arborescences*{color}

h3. Identifying output parameters of operations

Output parameters of the Activity operation can not be set into the output reply of the service operation using a simple XPath expression as for input parameters. An XSL style-sheet is required to generated the full output reply. It is identified using the annotation adding the element {{\{http://petals.ow2.org/se/activity/1.0}output}}. The XSL style-sheet name is set into the attribute {{*xsl*}} and loaded from the classloader. The XSL style-sheets are mainly located in the service-units, they can also be packaged as a shared library.

According to the Activity operation executed, its output parameters are transmitted to the XSL style-sheet through XSL parameters. You will use these XSL parameters to generate your service reply from your service request payload. See operation details to know the available XSL parameters.

{tip}For a unit test purpose, an extension of JUnit is available to test your XSL. See chapter "[Unit testing|#Unit_Testing]".{tip}

{color:red}*What about fault ?*{color}

h3. Operations

h4. Create an instance of a process definition

The operation creating instances of process definition is identified by the value *{{createProcInstOp}}* set on the attribute {{activityAction}}:
{code}
<wsdl:binding name="Order" xmlns:activity="http://petals.ow2.org/se/activity/1.0">
<wsdl:operation name="newOrder" type="...">
<activity:operation activityAction="createProcInstOp" />
<activity:variable name="customerName" value="/newOrderRequest/customerName" />
<activity:variable name="address" value="/newOrderRequest/address" />
<activity:output xsl="newOrderOutput.xsl" />
<wsdl:input/>
<wsdl:output/>
</wsdl:operation>
</wsdl:binding>
{code}

No input parameter is expected by this operation. Only variables can be set creating a process instance.

The XSL parameters available to generate the service output reply are:
|| XSL parameter name || Type || Description ||
| processInstanceId | String | Identifier of the process instance created |

It is possible to map several operations of the WSDL to the creation of process instances, but this has perhaps no sens.

h4. Complete task of a process instance

The operation completing a task of a process instance is identified by the value *{{completeTaskOp}}* set on the attribute {{activityAction}}:
{code}
<wsdl:binding name="Order" xmlns:activity="http://petals.ow2.org/se/activity/1.0" >
<wsdl:operation name="validOrder">
<activity:operation activityAction="completeTaskOp" />
<activity:input-parameter name="processInstanceId" value="/validOrderRequest/orderId" />
<activity:input-parameter name="taskId" value="/validOrderRequest/validationStepId" />
<activity:variable name="validationApproved" value="/validOrderRequest/isValidated" />
<activity:variable name="creditCardNumber" value="/validOrderRequest/creditCardNumber" />
<activity:output xsl="validOrderOutput.xsl" />
<wsdl:input/>
<wsdl:output/>
</wsdl:operation>
</wsdl:binding>
{code}

This operation accepts variables and requires the following input parameters:
|| Input parameter name || Type || Description || Required ||
| processInstanceId | String | Identifier of the process instance created | Yes |
| taskId | String | Identifier of the task | Yes |
Note: The completion status of the task is a variable and so it takes any form.

No XSL parameters is available to generate the service output reply. Your XSL style-sheet will be a "constant" style-sheet.

It is possible to map several operations of the WSDL to complete tasks, for example when a process can have several task in progress concurrently.

{color:red}*Mapping des parametres à faire*{color}

h4. Retrieve process instances

The operation retrieving process instances is identified by the value *{{retrieveProcInst}}* set on the attribute {{activityAction}}:
{code}
<wsdl:binding name="Order" xmlns:activity="http://petals.ow2.org/se/activity/1.0">
<wsdl:operation name="searchOrder" type="...">
<activity:operation activityAction="retrieveProcInst" />
<activity:input-parameter name="processInstanceId" value="/searchOrderRequest/orderId" />
<activity:input-parameter name="isActive" value="/searchOrderRequest/isInProgress" />
<activity:input-parameter name="responsibleUser" value="/searchOrderRequest/responsibleUser" />
<activity:input-parameter name="responsibleGroup" value="/searchOrderRequest/responsibleGroup" />
<activity:output xsl="searchOrderOutput.xsl" />
<wsdl:input/>
<wsdl:output/>
</wsdl:operation>
</wsdl:binding>
{code}

This operation requires the following input parameters:
|| Input parameter name || Type || Description || Required ||
| processInstanceId | String | Identifier of the process instance containing the tasks returned. | No |
| isActive | Boolean | Only active task are returned. | No |
| responsibleUser | String | Only select tasks for which the given user is a candidate are returned. | No |
| responsibleGroup | String | Only select tasks for which users in the given group are candidates are returned. | No |
It does not use variables.

It is possible to map several operations of the WSDL to search process instance, for example with different search criteria.

h1. Configuring the component

The component is be configured through the parameters of its JBI descriptor file. These parameters are divided in following groups:
* *JBI parameters* that have not to be changed otherwise the component will not work,
* *CDK parameters* that are parameters driving the processing of the CDK layer,
* and *Activity parametrs" that are relative to the engine "Activity".

{color:red}*TODO: Mettre une copie en exemple d'un descripteur JBI du SE*{color}
{code:lang=xml}<?xml version="1.0" encoding="UTF-8"?>
<jbi
version="1.0"
xmlns='http://java.sun.com/xml/ns/jbi'
xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
xmlns:petalsCDK="http://petals.ow2.org/components/extensions/version-5"
xmlns:xslt="http://petals.ow2.org/components/activity/version-1">

<component type="service-engine">
<identification>
<name>petals-se-activity</name>
<description>An Activity Service Engine</description>
</identification>

<component-class-name description="Activity Component class">org.ow2.petals.se.activity.ActivitySe</component-class-name>
<component-class-path><path-element/></component-class-path>
<bootstrap-class-name>org.ow2.petals.component.framework.DefaultBootstrap</bootstrap-class-name>
<bootstrap-class-path><path-element/></bootstrap-class-path>

<petalsCDK:acceptor-pool-size>3</petalsCDK:acceptor-pool-size>
<petalsCDK:processor-pool-size>10</petalsCDK:processor-pool-size>
<petalsCDK:processor-max-pool-size>50</petalsCDK:processor-max-pool-size>
<petalsCDK:properties-file></petalsCDK:properties-file>
<petalsCDK:jbi-listener-class-name>org.ow2.petals.se.activity.ActivityJBIListener</petalsCDK:jbi-listener-class-name>
</component>
</jbi>{code}

h2. CDK parameters
The component configuration includes the configuration of the CDK. The following parameters correspond to the CDK configuration.

{include:0 CDK Component Configuration Table 5.4.0}
{include:0 CDK Parameter scope}
{include:0 CDK Component Interceptor configuration}

h2. Component specific parameters

These parameters are extracted from parameters available for Activity 5.1.3:
* database parameters. Your are responsible to provide this database according to your needs. And especially, you must assume that the database is highly available to have a SE Activity highly available.

h3. Database parameters

{center}{*}Configuration of the component, Specific parameter part, Database*{center}
{table-plus}
|| {color:#333333}Parameter{color} || {color:#333333}Description{color} || {color:#333333}Default{color} || {color:#333333}Required{color} || Scope ||
| jdbc-url | URL of the database. The default database is an in-memory database | {center}jdbc:h2:mem:activiti;DB_CLOSE_DELAY=1000{center} | {center}Yes{center} | {center}Installation{center} |
| jdbc-driver | JDBC driver. Except for the default JDBC driver, it *must* be provided as shared-library. | {center}org.h2.Driver{center} | {center}Yes{center} | {center}Installation{center} |
| jdbc-username | Username used for the database connection. | {center}sa{center} | {center}Yes{center} | {center}Installation{center} |
| jdbc-password | Passwrd used for the database connection. | {center}""{center} | {center}Yes{center} | {center}Installation{center} |
| jdbc-max-active-connections | The number of idle connections that the database connection pool at maximum at any time can contain. | {center}10{center} | {center}No{center} | {center}Runtime{center} |
| jdbc-max-idle-connections | The number of active connections that the database connection pool at maximum at any time can contain. | {center}-{center} | {center}No{center} | {center}Runtime{center} |
| jdbc-max-checkout-time | The amount of time in milliseconds a connection can be 'checked out' from the connection pool before it is forcefully returned. | {center}20000 (20 seconds){center} | {center}No{center} | {center}Runtime{center} |
| jdbc-max-wait-time | This is a low level setting that gives the pool a chance to print a log status and re-attempt the acquisition of a connection in the case that it’s taking unusually long (to avoid failing silently forever if the pool is misconfigured). | {center}20000 (20 seconds){center} | {center}No{center} | {center}Runtime{center} |

h1. Logging

To enable traces of the Activity engine, you add in the logging configuration file of Petals ESB the following logger with the right level: {{xxxx}}

h1. Monitoring the component

{warning}In this documentation, the term "Allocated threads" must be understood as "Active threads", see [PETALSDISTRIB-37|https://jira.petalslink.com/browse/PETALSDISTRIB-37]. This naming error will be fixed in the next version.{warning}

h2. Using metrics

Several probes providing metrics are included in the component, and are available through the JMX MBean '{{org.ow2.petals:type=custom,name=monitoring_*<component-id>*}}', where {{*<component-id>*}} is the unique JBI identifier of the component.

h3. Common metrics

{include:0 CDK Component Monitoring Metrics 5.4.0}

h3. Dedicated metrics

No dedicated metric is available.

h2. Receiving alerts

Several alerts are notified by the component through notification of the JMX MBean '{{org.ow2.petals:type=custom,name=monitoring_*<component-id>*}}', where {{*<component-id>*}} is the unique JBI identifier of the component.

{tip}To integrate these alerts with Nagios, see [petalsesbsnapshot:Receiving Petals ESB defects in Nagios].{tip}

h3. Common alerts

{include:0 CDK Component Monitoring Alerts 5.4.0}

h3. Dedicated alerts

No dedicated alert is available.

{anchor:Unit_Testing}
h1. Unit testing

An extension of JUnit is available:
* to validate your WSDL,
* to test unitary your XSLs.

h2. Validating your WSDL

{color:red}*TODO*{color}

h2. Unit-testing your XSD

{color:red}*TODO*{color}

h1. Annex: Sample WSDL

h2. Abstract part:

{code}
<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions xmlns:tns="http://petals.ow2.org/se/activity/sample/order"
xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"

<xs:element name="newOrderRequest">

<xs:sequence>
<xs:element name="item" type="tns:ItemType"
maxOccurs="unbounded" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="newOrderResponse">

<!-- Message definitions for input and output -->
<wsdl:message name="newOrderRequest">
<wsdl:part name="newOrderRequest" element="tns:newOrderRequest" />
</wsdl:message>
<wsdl:message name="newOrderResponse">

<wsdl:portType name="Order">
<wsdl:operation name="newOrder">
<wsdl:input message="tns:newOrderRequest" />
<wsdl:output message="tns:newOrderResponse" />
</wsdl:operation>
<wsdl:operation name="validOrder">
<wsdl:input message="tns:validOrderRequest" />
<wsdl:output message="tns:validOrderResponse" />
</wsdl:operation>
<wsdl:operation name="searchOrder">
<wsdl:input message="tns:searchOrderRequest" />
<wsdl:output message="tns:searchOrderResponse" />
</wsdl:operation>
</wsdl:portType>

</wsdl:definitions>
{code}

h2. Implementation part

{code}
<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions xmlns:tns="http://petals.ow2.org/se/activity/sample/order"
xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
xmlns:activity="http://petals.ow2.org/se/activity/1.0" targetNamespace="http://petals.ow2.org/se/activity/sample/order">

<wsdl:import location="OrderAbstract.wsdl"

<wsdl:output />
</wsdl:operation>

</wsdl:operation>

</wsdl:operation>
</wsdl:binding>

</wsdl:definitions>
{code}