询问Moqui是否内置主题通知邮件推送机制，需自定义NotificationMessageListener吗？

Great question! Let's walk through how you can handle sending email notifications to subscribed users in Moqui, covering both built-in capabilities and when you might need a custom listener.

Built-in Mechanism: Use Moqui's Native Notification Services #

Moqui actually has out-of-the-box support for sending notifications to subscribed users based on specific topics. Here's how it works:

• Subscription Management: The NotificationSubscription entity lets you track which users are subscribed to which topics. You can filter subscriptions by the topic field to target exactly the users who care about a specific event.
• Notification Message Service: The send#NotificationMessage service is designed to handle bulk notifications. It can automatically pull subscribed users for a given topic, apply email templates, and send messages using Moqui's configured email sender.
• Email Configuration: First, make sure your email settings are configured in moqui-conf.xml (SMTP server, default from address, etc.) so Moqui can send emails.

Example: Using the Built-in Service #

Here's a Groovy snippet to trigger a notification for a specific topic:

// Send email notifications to users subscribed to "ORDER_STATUS_UPDATED" topic
ec.service.sync().name("send#NotificationMessage").parameters([
    topic: "ORDER_STATUS_UPDATED",
    notificationTypeEnumId: "NTT_EMAIL", // Specify email as the notification type
    fromAddress: "alerts@yourstore.com",
    subject: "Your Order Status Changed",
    body: "Hi ${partyId},\n\nYour order ${orderId} has been updated to ${status}.\n\nThanks,\nThe Team"
])

This service will automatically fetch all users subscribed to the ORDER_STATUS_UPDATED topic and send them the email with the provided subject and body (you can also use Freemarker templates for more dynamic content).

When to Implement a Custom NotificationMessageListener #

You'll need a custom listener if you require more control or specialized logic that the built-in service doesn't cover, such as:

• Complex subscription rules (e.g., filtering users based on additional attributes beyond just the topic)
• Custom email templating logic that goes beyond Moqui's default template support
• Sending notifications to multiple channels (email + SMS + in-app) in one workflow
• Adding custom logging or error handling for failed notifications

Example: Custom Listener Implementation #

First, create a class that implements the NotificationMessageListener interface:

import org.moqui.notification.NotificationMessage;
import org.moqui.notification.NotificationMessageListener;
import org.moqui.context.ExecutionContext;
import java.util.List;
import java.util.Map;

public class CustomEmailNotificationListener implements NotificationMessageListener {
    @Override
    public void onNotificationMessage(NotificationMessage notificationMessage, ExecutionContext ec) {
        // Fetch users subscribed to the target topic
        List<Map<String, Object>> subscriptions = ec.entity.find("moqui.notification.NotificationSubscription")
                .condition("topic", notificationMessage.getTopic())
                // Add custom filter if needed (e.g., only active users)
                .condition("active", "Y")
                .list();

        // Send email to each subscriber
        for (Map<String, Object> subscription : subscriptions) {
            String userEmail = (String) subscription.get("emailAddress");
            String userName = (String) subscription.get("partyName");

            // Use Moqui's send#Email service for actual delivery
            ec.service.sync().name("send#Email").parameters(Map.of(
                    "toAddress", userEmail,
                    "fromAddress", "custom-alerts@yourstore.com",
                    "subject", notificationMessage.getSubject(),
                    "body", String.format("Hi %s,\n\n%s", userName, notificationMessage.getBody())
            ));
        }
    }
}

Then register your listener in moqui-conf.xml:

<notification-listener class="com.yourcompany.notification.CustomEmailNotificationListener"/>

Final Takeaway #

• Use built-in services if you need straightforward topic-based email notifications to subscribed users—it's quick, requires minimal code, and leverages Moqui's existing infrastructure.
• Build a custom listener when you need tailored logic that the native service can't handle.

内容的提问来源于stack exchange，提问作者Diego