Be aware: this is experimental! available for free on downloads page.
The Newsletter Grabber Extension is an “interceptor” of other forms published in your site (like a contact form) and it tries to and subscribe an email address when those forms are submitted.
The grabber can be configure with a set of grabbing rules that are checked every time a form is submitted from your blog. When a rule matches, the grabber tries to extract a “subscription” (an email address and/or other data) from the submitted fields following the matching rule configuration.
To help you in composing the rules and find the key-fields (see below), the grabber has a recorder to track the submitted fields of any form.
The rules
A rule is composed of a trigger field which must be present in the intercepted data. A trigger field is something like a check box which the user can check to indicate his wish to signup for the newsletter while submitting the form. For example while submitting a contact form.
Usually most of the form composers let you to add a custom check box which you can for for your newsletter opt-in offer.
The trigger field can be matched against a specific value or only the presence of it can be evaluated.
The email field is where the grabber should look for an email address to subscribe. Actually no other fields are available in this experimental version.
As an option, you can force the grabber rule to scan all the submitted data ad search for an email without looking in for a specific field.
The recorder
The recorder, when activated, simply stores the last set of data it can intercept from a form. It limits its activity when an administrator is using the site, so you must do a submission of a form to analyse it while connected as administrator.
The recorder lists all the field names and values that can be used to compose a intercepting rule. For who is able to read the HTML of a form or using tools like Firebug or other debug consoles, a direct form structure analysis can suffice without the need of this recorder (of course).