Translate \n to <br /> in fct labels, too

[salim-b]

Before, this only worked for colums of type character. This PR adds support for columns of type factor.

The linebreak conversion was first introduced in v4.6.0, see also #851

[cpsievert]

Thanks, could you provide some examples of where this is relevant and also write a few tests?

[salim-b]

Sorry for the delay! I finally found some time to meet your requests.

could you provide some examples of where this is relevant

This is relevant whenever you want to plot a data column of type factor with labels containing line breaks. Currently, the line breaks are only translated to HTML (<br>) when the column is of type character. But factor columns are not only very common but also very convenient to work with (using pkg forcats), i.e. to (re)arrange, extend, split into "buckets" etc.

A very simple example with multiline factor labels

library(magrittr)

iris %>%
    dplyr::mutate(Species =
                      Species %>%
                      forcats::fct_relabel(paste0,
                                           "\n\n(third line)\n(fourth line)")) %>%
    plotly::plot_ly(x = ~Sepal.Length,
                    y = ~Species)
#> No trace type specified:
#>   Based on info supplied, a 'bar' trace seems appropriate.
#>   Read more about this trace type -> https://plot.ly/r/reference/#bar

^{Created on 2020-04-23 by the reprex package (v0.3.0)}

The same example when the column is converted to type character before plotting

library(magrittr)

iris %>%
  dplyr::mutate(Species =
                  Species %>%
                  forcats::fct_relabel(paste0,
                                       "\n\n(third line)\n(fourth line)") %>%
                  as.character()) %>%
  plotly::plot_ly(x = ~Sepal.Length,
                  y = ~Species)
#> No trace type specified:
#>   Based on info supplied, a 'bar' trace seems appropriate.
#>   Read more about this trace type -> https://plot.ly/r/reference/#bar

^{Created on 2020-04-23 by the reprex package (v0.3.0)}

and also write a few tests?

I pushed 841e7e9 which adds an additional test to tests/testthat/test-plotly.R. I'm very new to writing tests (or R packages to begin with), so please bear with me :)

[cpsievert]

Thanks for the update, this is looking good @salim-b!

A couple minor nitpicks:

• Could you please remove the %>% and the forcats dependency in the tests?
• Please switch the order in the DESCRIPTION (I'd prefer that all single authors are listed first, then Plotly)

[salim-b]

• Could you please remove the %>% and the forcats dependency in the tests?

Sorry, I assumed it would be fine to use forcats since it's listed under Suggests: in DESCRIPTION. I have replaced it now with equivalent base R code.

Regarding %>%: The pipe operator is used throughout this test file. Why can't I use it, too?

• Please switch the order in the DESCRIPTION (I'd prefer that all single authors are listed first, then Plotly)

Done :)

[salim-b]

@cpsievert I've added the missing news item in d60898a. I'd be glad if you could merge this PR. 🙂

[cpsievert]

Thank you!