Remove text which is displayed on bars in plotly bar chart

Question

I have the data.frame below:

dp <- structure(list(`Demand Per Section` = c(125, 350, 100, 538, 75, 
25, 138, 138, 75, 150, 37, 225, 35, 40, 125, 25, 25, 125, 50, 
250, 88, 325, 4, 50, 6, 5, 500, 500, 3, 146, 5, 34, 15, 51, 2, 
32, 48, 18, 5, 6, 44, 16, 46, 12, 100, 750, 15, 500, 30, 333), 
    `Element Name` = c("Nitric acid (concentrated)", "Sulphuric acid(concentrated)", 
    "2-hydroxybenzoic acid", "Acetic anhydride", "2-Naphthol", 
    "Sodium Hydroxide", "Phenyl hydrazine hydrochloride", "Glucose", 
    "Sodium acetate", "Aniline", "Zinc poweder", "2-amino-benzoic acid", 
    "1.3-dihydroxybenzene", "Ethyl acetate", "hydroxy benzene", 
    "phenyl methanol", "Sodium carbonate", "Potassium permanganate", 
    "Sodium bisulfite.", "Hydrochloric acid (concentrated)", 
    "Sodium nitrite", "Copper(II) sulfate", "Methyl orange", 
    "EtOH", "Distilled water", "cuper ion", "ammonium hydroxide", 
    "ammonium hydroxide", "Iron( III)", "Potassium Thiocyanate", 
    "ferric ammonium sulfate", "Ammonium Sulfate", "sodium hypochlorite", 
    "Acetic acid", "Phenolphthalein", "Sodium carbonate", "Sodum hydroxide", 
    "Acetic acid", "Phenolphthalein", "Methyl orange", "Phosphoric acid", 
    "Sodium carbonate", "Iron(II) sulfate", "Potassium permanganate", 
    "Sulfuric Acid", "Barium Chloride.monoHydrate", "Distilled water", 
    "nickel Sulphate", "Dimethyl glyoxime (DMG)", "Calsium chloride"
    ), Department = c("Chemsitry", "Chemsitry", "Chemsitry", 
    "Chemsitry", "Physics", "Physics", "Physics", "Physics", 
    "Physics", "Physics", "Physics", "Chemsitry", "Chemsitry", 
    "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry","Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", 
    "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", 
    "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", 
    "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", 
    "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", 
    "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", "Chemsitry", 
    "Chemsitry", "Chemsitry"), DemandCourse = c(375, 1050, 300, 
    1614, 225, 75, 414, 414, 225, 450, 111, 675, 105, 120, 375, 
    75, 75, 375, 150, 750, 264, 975, 20, 250, 30, 25, 2500, 2500, 
    15, 730, 25, 170, 75, 255, 10, 160, 144, 54, 15, 18, 132, 
    48, 138, 36, 300, 2250, 45, 1500, 90, 999), `Amount Available` = c(1000, 
    3000, 4000, 1000, 750, 750, 2000, 5000, 150, 24000, 450, 
    3000, 1400, 400, 400, 250, 250, 1000, 1000, 7500, 6400, 900, 
    250, 1500, 20000, 50, 300, 4000, 200, 3000, 500, 1200, 1000, 
    6000, 900, 250, 200, 6000, 900, 250, 200, 250, 150, 1000, 
    15000, 3000, 20000, 1500, 600, 7500)), row.names = c(NA, 
-50L), class = c("tbl_df", "tbl", "data.frame"), na.action = structure(c(`1` = 1L, 
`24` = 24L, `32` = 32L, `36` = 36L, `38` = 38L, `42` = 42L, `45` = 45L, 
`49` = 49L, `66` = 66L, `111` = 111L, `140` = 140L, `151` = 151L, 
`154` = 154L, `164` = 164L, `169` = 169L, `171` = 171L, `175` = 175L,`185` = 185L, `193` = 193L, `227` = 227L, `252` = 252L, `253` = 253L, 
`256` = 256L, `257` = 257L, `258` = 258L, `262` = 262L, `263` = 263L, 
`265` = 265L, `275` = 275L, `276` = 276L, `277` = 277L, `279` = 279L, 
`280` = 280L, `281` = 281L, `282` = 282L, `283` = 283L, `284` = 284L, 
`285` = 285L, `286` = 286L, `288` = 288L, `289` = 289L, `290` = 290L, 
`291` = 291L, `292` = 292L, `293` = 293L, `298` = 298L, `299` = 299L, 
`300` = 300L, `302` = 302L, `303` = 303L, `304` = 304L, `308` = 308L, 
`309` = 309L, `310` = 310L, `311` = 311L, `312` = 312L, `314` = 314L, 
`315` = 315L, `316` = 316L, `317` = 317L, `318` = 318L, `319` = 319L, 
`323` = 323L, `325` = 325L), class = "omit"))

and I have created the stacked bar chart below.

How to remove the text that is displayed on the bars?

fig <- plot_ly(x = ~`Element Name`,text=~Department,
               
data = dp) %>% 
  add_bars(y = ~`DemandCourse`, name = "Demand",
           hovertemplate = "Chemical Name: %{x}<br>Demand: %{y}<br>Department: %{text}") %>% 
  add_bars(y = ~`Amount Available`, name = "Amount Available",
           hovertemplate = "Chemical Name: %{x}<br>Available Amount: %{y}<br>Department: %{text}") %>% 
  
  layout(showLegend = T, barmode = "stack",
         xaxis = list(title = "Element Name",tickangle=45),
         yaxis = list(title = "Amount Available"),
         title="Amount and Demand per Element")
fig

Answer 1

You can add textposition = "none" to each trace so that it is only used in the tooltip.

fig <- plot_ly(x = ~`Element Name`,text = ~Department, data = dp) %>% 
  add_bars(y = ~`DemandCourse`, 
           name = "Demand", 
           textposition = "none",          # <--- added here
           hovertemplate = paste0("Chemical Name: %{x}<br>", 
                                  "Demand: %{y}<br>",
                                  "Department: %{text}<extra></extra>")) %>% 
  add_bars(y = ~`Amount Available`,
           name = "Amount Available", 
           textposition = "none",          # <--- added here
           hovertemplate = paste0("Chemical Name: %{x}<br>",  
                                  "Available Amount: %{y}<br>",
                                  "Department: %{text}<extra></extra>")) %>% 
  layout(barmode = "stack",                # <--- dropped showLegend (doesn't go here)
         xaxis = list(title = "Element Name", tickangle=45),
         yaxis = list(title = "Amount Available"),
         title = "Amount and Demand per Element")
fig

Answer 2

In my opinion using hovertext instead of text and textposition = "none" is the cleaner approach. hovertext is intended to change the hover info.

The text parameter on the other hand might be needed later to actually display a text in the plot (unrelated to the hover info).

library(plotly)

fig <- plot_ly(x = ~`Element Name`, hovertext = ~Department, data = dp) %>%
  add_bars(y = ~`DemandCourse`, 
           name = "Demand", 
           hovertemplate = paste0("Chemical Name: %{x}<br>", 
                                  "Demand: %{y}<br>",
                                  "Department: %{hovertext}<extra></extra>")) %>%
  add_bars(y = ~`Amount Available`,
           name = "Amount Available", 
           hovertemplate = paste0("Chemical Name: %{x}<br>",  
                                  "Available Amount: %{y}<br>",
                                  "Department: %{hovertext}<extra></extra>")) %>%
  layout(showlegend = TRUE,
         barmode = "stack",
         xaxis = list(title = "Element Name", tickangle=45),
         yaxis = list(title = "Amount Available"),
         title = "Amount and Demand per Element")
fig

Also see this related answer.