Filter limitations

[dsblank]

Friendly gramps web neighbor here!

It occured to me that almost all of the filters included in Gramps Web can be expressed via GOQL (gramps object query language) syntax. That has a few implications:

1. You could, using a gramps-core addon create SQL-backed queries, execute those efficiently in SQL
2. Although each of those filters is a separate SQL sweep through the data (still very fast, compared to a Python sweep)
3. You could also send the same GOQL where-exp to the /query/ endpoints

That also implies that you could fairly easily construct a filter-builder to allow AND/OR/NOT and combine those filters in ways not possible in Gramps Web today. That also allows the where-expressions to be compiled by GOQL into a single SQL sweep. Superfast!

And, you are then only a step away from building "custom" filters out of GOQL user-created where-exp primitives.

[DavidMStraub]

Thanks for the idea!

Combining filters with and/or/not are already possible in the "old" endpoints, especially since this change: gramps-project/gramps-web-api#852

It's just not exposed in the frontend currently.

As a first step of improving filtering in Gramps Web, I'm replacing the old GOQL (which was not exposed in the frontend either) by a gramps-object-query-language FilterRule, but not using the addon (which I think is more appropriate for Gramps desktop).
gramps-project/gramps-web-api#1013

This doesn't use the SQL-optimized path yet, that will come later.