consider legendgroup a mapping variable, closes #1148

Author: cpsievert

R/plotly_build.R

@@ -189,7 +189,7 @@ plotly_build.plotly <- function(p, registerFrames = TRUE) {
       dataArrayAttrs, special_attrs(trace), npscales(), "frame",
       # for some reason, text isn't listed as a data array in some traces
       # I'm looking at you scattergeo...
-      ".plotlyGroupIndex", "text", "key", "fillcolor", "name"
+      ".plotlyGroupIndex", "text", "key", "fillcolor", "name", "legendgroup"
     )
     tr <- trace[names(trace) %in% allAttrs]
     # TODO: does it make sense to "train" matrices/2D-tables (e.g. z)?
@@ -210,11 +210,7 @@ plotly_build.plotly <- function(p, registerFrames = TRUE) {
       if (any(isSplit)) {
         paste2 <- function(x, y) if (identical(x, y)) x else paste(x, y, sep = br())
         splitVars <- builtData[isSplit]
-        traceIndex <- Reduce(paste2, splitVars)
-        if (!is.null(trace$name)) {
-          traceIndex <- paste2(traceIndex, trace$name)
-        }
-        builtData[[".plotlyTraceIndex"]] <- traceIndex
+        builtData[[".plotlyTraceIndex"]] <- Reduce(paste2, splitVars)
         # in registerFrames() we need to strip the frame from .plotlyTraceIndex
         # so keep track of which variable it is...
         trace$frameOrder <- which(names(splitVars) %in% "frame")

R/utils.R

@@ -492,7 +492,7 @@ verify_attr <- function(proposed, schema) {
       proposed[[attr]] <- structure(proposed[[attr]], apiSrc = TRUE)
     }
 
-    if (length(proposed$name) > 0) {
+    if (length(proposed[["name"]]) > 0) {
       proposed$name <- uniq(proposed$name)
     }
 

tests/testthat/test-plotly.R

@@ -251,3 +251,31 @@ test_that("Vector of redundant text is reduced to string when hoveron=fills", {
     d[[2]]$text == '<br> <b>Example</b> of <em>custom</em> hover text <br> B <br> xyz <br>.'
   )
 })
+
+
+test_that("Can map data to legendgroup", {
+  d <- data.frame(
+    x = 1:100,
+    y = runif(100),
+    group = letters[1:5]
+  )
+  
+  l <- plot_ly(data = d, x = ~x, y = ~y) %>%
+    add_bars(color = ~group,  legendgroup = ~group) %>%
+    add_markers(color = ~group, legendgroup = ~group) %>%
+    plotly_build()
+  
+  expect_length(l$x$data, 10)
+  
+  markers <- compact(lapply(l$x$data, function(tr) if (tr$type == "scatter") tr))
+  for (i in seq_along(markers)) {
+    expect_length(markers[[i]]$legendgroup, 1)
+    expect_true(markers[[i]]$legendgroup == letters[[i]])
+  }
+  
+  bars <- compact(lapply(l$x$data, function(tr) if (tr$type == "bar") tr))
+  for (i in seq_along(bars)) {
+    expect_length(bars[[i]]$legendgroup, 1)
+    expect_true(bars[[i]]$legendgroup == letters[[i]])
+  }
+})