shiny - update layer refocuses map

[SymbolixAU]

This happens when you've initialised the map with data, then use an observeEvent() to change it.

(and it's almost replicating the behaviour we sometimes see where the layer is 'sticky'. Maybe they're related?)

library(shiny)
library(shinydashboard)
library(sf)

ui <- dashboardPage(
	dashboardHeader()
	, dashboardSidebar()
	, dashboardBody(
		mapdeckOutput(
			outputId = "map"
			, height = "600"
		)
		, actionButton(
			inputId = "btn"
			, label = "btn"
		)
	)
)
server <- function( input, output ) {
	
	output$map <- renderMapdeck({

		mapdeck( style = mapdeck_style("dark") ) %>%
		add_path( data = roads[1:500, ] )
	})
	
	observeEvent({input$btn},{
		
		mapdeck_update( map_id = "map" ) %>%
			add_path( data = roads[500:1000, ], update_view = FALSE )
	})
}

shinyApp( ui, server )

[SymbolixAU]

found the culprit - it's my update_view functions & logic.

For some reason the viewState is not keeping a reference to the auto-calcualted "location" in the first add_path(), so on the button presses it's not being set at the correct location, and requires interacting with the map to force a re-draw (or using update_view = TRUE in the subsequent add_path() calls

Time for a re-think...

It seems to be the solution is a recommendation:

• If you'll be adding & removing layers dynamically and want to use update_view = FALSE each udpate, don't supply data to the original mapdeck() call

[SymbolixAU]

example on the website: https://symbolixau.github.io/mapdeck/articles/tips_tricks.html#update_view

[SymbolixAU]

related - #137
but I think this too is fixed now.