fix for #16

R/sfencoded.R

@@ -24,7 +24,8 @@ str.wkt_column <- strSfEncoded
 
 #' @export
 `[.sfencoded` <- function(x, i, j, ..., drop = TRUE) {
-
+
+  encodedClass <- attr(x, 'class')[1]
   geomColumn <- attr(x, "encoded_column")
   wktColumn <- attr(x, "wkt_column")
   attr(x, "sfAttributes") <- NULL
@@ -35,7 +36,11 @@ str.wkt_column <- strSfEncoded
 
   if( is.null(attr(x, "encoded_column")) && is.null(attr(x, "wkt_column")) ){
     x <- removeSfencodedClass(x)
+  } else {
+    ## re-attach 'sfencoded' attribute?
+    attr(x, 'class') <- unique(c(encodedClass, attr(x, 'class')))
   }
+
   return(x)
 }
 

tests/testthat/test-sfencoded.R

@@ -18,6 +18,16 @@ test_that("sfencoded converted to data.frame",  {
   expect_true(class(x) == "data.frame")
 })
 
+test_that("subsetting retains all class attributes", {
+
+  testthat::skip_on_cran()
+  library(sf)
+  nc <- sf::st_read(system.file("shape/nc.shp", package="sf"), quiet = T)
+  enc <- encode(nc)
+  expect_true(all(attr(enc, 'class') == attr(enc[1, ], 'class')))
+
+})
+
 test_that("sfencoded attributes are removed", {
 
   testthat::skip_on_cran()