Setting theme() after using a complete theme (like theme_minimal()) no longer works

[thomasjwood]

It used to be the behavior of ggplot that you could use a default theme (like theme_minimal()) and then specify a further change with a subsequent use of theme(). That no longer seems to be the case.

library(tidyverse)
library(ggtext)

ggplot(
  economics, aes(date, unemploy)
  ) + 
  geom_line() +
  scale_x_date(
    breaks = seq.Date(
      "1970-01-01" %>% as.Date,
      "2012-01-01" %>% as.Date, 
      length.out = 5
      ),
    labels = str_c(
      "**",
      seq(1970, 2010, by  = 10),
      "**"
      )
  ) +
  theme(
    axis.text.x =  element_markdown()
  ) 

returns:

Now, imagine if I wanted to keep the markdown for the x axis labels, but use theme_minimal() otherwise. You formerly could use

ggplot(
  economics, aes(date, unemploy)
  ) + 
  geom_line() +
  scale_x_date(
    breaks = seq.Date(
      "1970-01-01" %>% as.Date,
      "2012-01-01" %>% as.Date, 
      length.out = 5
      ),
    labels = str_c(
      "**",
      seq(1970, 2010, by  = 10),
      "**"
      )
  ) +
  theme_minimal() +
  theme(
    axis.text.x =  element_markdown()
  ) 

but now it returns (ie the theme(axis.text.x = ....) is ignored.)

How can one set a theme() element after using a complete theme?

[teunbrand]

It works if you set axis.text.x.bottom. I'm sure this is due to a pivot towards S7 and element inheritance being a bit rough.