Silva has a finely grained subscription feature. Subscription allows visitors to subscribe and receive email notification of updates to a page, a folder or a publication on the site. The Silva Manager enables the subscription feature for the whole site. Editors can then choose to activate this subscription functionality for some or all of their content.
The Manage can enable or disable the subscriptions feature for the whole Silva site in the ZMI under the services tab in service_subscriptions (Subscription Service).
The email templates that are used for creating the email notifications sent by the subscription extension are found in the service_subscriptions content tab. It is strongly advised to change the "From:" addresses in these templates to reflect the configuration of your site.
The site admin can also choose to create an instance of the MaildropHost object for more efficient email handling.
If the MaildropHost Product is not installed, the subscription extension will use the MailHost Product that is distributed with Zope.
The MailHost will send email ‘synchronously’, meaning, the calling code will have to wait for the email delivery to complete. This can potentially cause huge slowdowns.
To overcome this issue it is highly recommended to use the MaildropHost replacement product, which uses a spool based mechanism for sending the email. Whenever an email needs to be sent, it is actually written to a temporary file in a spool directory on the filesystem. A separate delivery process (independent from the Zope processes) will poll the spool directory and deliver the emails using the settings as configured in the ‘config.py’ file for this Product. See the MaildropHost Product’s README.txt for details.
The MaildropHost Product can be found here:
http://www.dataflake.org/software/maildrophost
The Silva Subscriptions feature needs MaildropHost version 1.9 or higher.
A “subscribe to this page” link must added by the Manager or template designer. The link should be added in the layout template of the public website (see the Silva documentation for an example). The URL to the subscription UI is the URL for the content object with ‘/public/subscriptor’ appended to it.
E.g. for the document you’re reading, the link would be:
http://.../subscription_config/public/subscriptor
An Editor can enable subscriptions for a particular subtree or individual document from the Silva management area.
For a visitors to be able to subscribe to part of the site, they need to click on the subscribe to this page link located on a subscribable page and then fill in a subscription form. The Subscription service will then send an email confirmation message to the email address supplied. This message contains a link that, if clicked, will confirm the subscription.
Cancelling a subscription follows a similar pattern: the visitor has to click the unsubscribe button in the subscription user interface. The confirmation message will contain a link that, if followed, will cancel the subscription.
Once subscribed a visitor will receive a message whenever the document is published. This email will contain a link to the document, as well as a link to the subscription form for unsubscribing.
Note: Visitors can also subscribe to Silva Folders and Publications. This means they’ll be notified about all changes of content contained in these areas. In other words, visitors can subscribe to a complete subtree of the content. This could result in a lot of mail in the visitor’s inbox.
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