Hello, I think it's a great idea but unfortunately there is nothing exactly like this built-in to the Toolset suite. It sounds like an excellent candidate for a custom code solution, as there are some limitations in Toolset that present problems that are not easily overcome with the built-in features. I think you would encounter all of these limitations, at the very least:
- No arbitrary cron/scheduler interface. There are no cron or scheduler options built-in to Toolset that would enable periodic automated email notifications at arbitrary intervals. Toolset's email notification scheduler is currently built around a Forms-based workflow. Email notifications are created and attached to a specific Form, and triggered on a schedule directly linked to those Form submissions. It sounds like you might need a way to create and trigger email notifications on an arbitrary schedule, like once a day/week/month or something similar, but that infrastructure does not currently exist. Instead, this email notification schedule would have to be based on when new posts are submitted via Forms. Posts that are imported or created in wp-admin would not trigger these email notifications, and furthermore I suspect clients would prefer the ability to choose the frequency of those updates, and unsubscribe to specific saved search notifications (CAN-SPAM compliance), so I suspect a more arbitrary schedule system is preferred. It would also need the ability to send or not send notifications based on arbitrary programmatic conditionals. This needs a fully custom solution, not easily achieved with built-in features.
- No built-in method to save custom searches or search parameters. There is no built-in workflow for saving search criteria or search URLs, so you would need to implement something custom like a set of custom fields (repeatable field group or RFG) or custom post type corresponding to a saved search. A repeatable field group or separate custom post type would be useful in this case, so you could save multiple instances of subscriptions along with the various field options or search URL, along with a search "name" for future reference, perhaps a field indicating the desired schedule/frequency, the date the last search results were captured for comparison, the results from that date, and other relevant information for each subscription. RFGs are not supported in User profiles, nor are post relationships, so I suspect a separate custom post type is required here.
- No built-in method for comparing sets of search results. Since the key criteria for sending these notifications would be a comparison of search results over time, you'd need a way to save not only the search criteria but also the results from a previous query. We have a PHP API you can use to get search results, so a custom solution here might rely on that API for performing
a search, gathering the results, comparing the current results with a set of previous results from a custom field somewhere, and saving the new results into that custom field for future comparisons.
https://toolset.com/documentation/programmer-reference/views-api/#get_view_query_results
You can see that it's a fairly involved feature with several aspects that are not easily achieved in the current system using built-in functionality. I did a quick search in our internal tracker for feature requests, and a search of the forums for similar requests, but didn't find anything like what you've described here in a previous feature request. I saw a couple of tickets with similar questions over the last few years, but there does not appear to be a large enough number of requests to get our developers to prioritize this feature. I suspect the developers would consider this a low priority if submitted as a feature request, given the amount of new development required to implement this entire feature. That request would likely sit in our development queue for quite some time given the number of higher priority requests, so I suggest reaching out to an independent contractor if you'd like to get this implemented in a timely manner.
