Workflows and triggers: hooks on content operations #

This page is for developers who would hook business logic into an ORM's save events, write a Django post_save signal, or model an approval process with a state machine library. In Exponential, operations such as publishing content or confirming an order can start a workflow before or after they run. A workflow is a list of event types (PHP classes), connected to an operation by a trigger, and it can hold the operation back until something happens: an approval, a payment, a date (Workflows, triggers and events).

Contents #

1. The pieces
2. Operations you can hook
3. What an event can answer
4. Writing an event type
5. Compared with other frameworks
6. When to use what

The pieces #

Workflows are configured by administrators in the browser; your extension provides the event types.

Operations you can hook #

settings/workflow.ini [OperationSettings] AvailableOperationList[] lists the operations that offer triggers. Shipped active: content_publish, before_shop_confirmorder, shop_checkout, shop_addtobasket, shop_updatebasket. Others are listed commented out (content_move, content_hide, content_delete, content_updatesection, content_read, content_updateobjectstate, user_activation, user_password ...); an installation enables them in an override. Your own persistent object classes have no operations: emit an event of your own instead (Events and listeners).

What an event can answer #

execute() returns a status constant of eZWorkflowType:

Waiting processes are listed in Setup > Workflow processes. Without the frequent cron part, content waiting for a deferred event never publishes (Scheduled tasks).

Writing an event type #

From Writing a workflow event type:

# extension/expdemo/settings/workflow.ini.append.php
<?php /* #?ini charset="utf-8"?
[EventSettings]
ExtensionDirectories[]=expdemo
AvailableEventTypes[]=event_expnotify
*/ ?>

<?php
// extension/expdemo/eventtypes/event/expnotify/expnotifytype.php
class expNotifyType extends eZWorkflowEventType
{
    const WORKFLOW_TYPE_STRING = 'expnotify';

    public function __construct()
    {
        parent::__construct( self::WORKFLOW_TYPE_STRING, ezpI18n::tr( 'extension/expdemo', 'Notify the archive' ) );
        $this->setTriggerTypes( array( 'content' => array( 'publish' => array( 'after' ) ) ) );
    }

    function execute( $process, $event )
    {
        $parameters = $process->attribute( 'parameter_list' );
        $object = eZContentObject::fetch( (int)$parameters['object_id'] );
        if ( !$object )
            return eZWorkflowType::STATUS_WORKFLOW_CANCELLED;
        // queue slow work instead of doing it here
        return eZWorkflowType::STATUS_ACCEPTED;
    }
}

eZWorkflowEventType::registerEventType( expNotifyType::WORKFLOW_TYPE_STRING, 'expNotifyType' );

Compared with other frameworks #

When to use what #

Related pages #

• Workflows guide
• Workflow event pattern
• Content jobs
• Free documentation: this page is free to copy, translate and improve under the GNU FDL 1.3.