Problem: I have a View of custom posts that displays a map with markers, using a distance filter and sorting results by distance. In some cases the distance center is set by a URL parameter, and in others, it is set by a shortcode attribute. I have implemented some custom code in a wpv_view_settings filter to toggle between the shortcode attribute and the URL parameter. In the cases where distance center is set by a shortcode attribute, I am using another custom shortcode to get the User's predicted zip code. That shortcodes an external service to get a predicted zip code based on the User's IP address. The custom zip code service seems to be working correctly, and the results of the View seem to be accurate.
However, in the cases where this zip code shortcode is used to set the View's distance Query Filter by shortcode attribute, the View consistently causes the page generation time to jump by 3 or more seconds. I would like to try to optimize the page load time as much as possible.
Solution: In this case, testing revealed that using the custom zip shortcode inside a wpv_view_settings filter callback was the source of the delay in page generation, for some reason not fully understood. Replacing that shortcode with a hard-coded zip code resulted in a page generation time just a fraction of a second higher than the page without the View present at all.
Optimization of the zip code shortcode is necessary to prevent the latency seen in page generation time.
