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rerror-handlingplotlyplotly-dash

Problem with dash: Error in htmlDiv(...), could not find function "htmlDiv"

I get an error when running this code:

library(dash)

app <- Dash$new()

app$layout(
  htmlDiv(
    list(
      dccGraph("graph"),
      dccSlider(
        id = "slider",
        min = 500, max = 700, step = 50, value = 600,
        marks = list(500, 600, 700)
      )
    )
  )
)

Error:

Error in htmlDiv(list(dccGraph("graph"), dccSlider(id = "slider", min = 500,  : 
  could not find function "htmlDiv"

Now I see that htmlDiv is part of dashCoreComponents, but according to https://github.com/plotly/dash-core-components "As of Dash 2, the development of dash-core-components has been moved to the main Dash repo. This package exists for backward compatibility"

So I should not need to load library(dashCoreComponents) right? But even if I try, I would not be able to, because it is part of the library(dash) if I understand correctly. So it can't be because of this right?

Solution

  • Interesting problem, exacerbated by the fact that dash was removed from CRAN last year, and perhaps further confused by the presence of a since-dropped dashR package. Your code seems legit from that perspective. However, looking at cran/dash/R/dashHtmlComponents.R and its NAMESPACE, it is defined but not exported. This seems like a bug-report, though it's not hard to get the idea that the concept of Dash for R is encouraged but not well supported.

    The app can be made to work by :::-calling it.

    library(dash)

app <- Dash$new()

app$layout(
  dash:::htmlDiv(
    list(
      dccGraph("graph"),
      dccSlider(
        id = "slider",
        min = 500, max = 700, step = 50, value = 600,
        marks = list(500, 600, 700)
      )
    )
  )
)
# Warning in fn_summary$obj : partial match of 'obj' to 'objs'
# Warning in fn_summary$obj : partial match of 'obj' to 'objs'
# Warning in fn_summary$obj : partial match of 'obj' to 'objs'
# Warning in fn_summary$obj : partial match of 'obj' to 'objs'
# Warning in fn_summary$obj : partial match of 'obj' to 'objs'
# Warning in fn_summary$obj : partial match of 'obj' to 'objs'
# Warning in fn_summary$obj : partial match of 'obj' to 'objs'
# Warning in fn_summary$obj : partial match of 'obj' to 'objs'

app

    dash for R sample app

    (This is not a sustainable solution, however, it would be better to fix the package itself.)