Can't pipe into qplot with non-auto geom

[PatrickRobotham]

I can plot a histogram with any of:

my_data <- rnorm(100);
qplot(my_data);
qplot(my_data, geom="auto");
qplot(my_data, geom="histogram");

my_data %>% qplot;
my_data %>% qplot(geom="auto");
my_data %>% qplot(geom="auto", x = .);

my_data %>% ggplot(data = data.frame(foo=.), mapping=aes(x = foo)) +
geom_histogram();

I would expect the same behaviour from

my_data %>% qplot(geom="histogram");
my_data %>% qplot(geom="histogram", x = .);

but instead these two fail with

Don't know how to automatically pick scale for object of type list.
Defaulting to continuous
Error in as.data.frame.default(x[[i]], optional = TRUE,
stringsAsFactors = stringsAsFactors) :
  cannot coerce class "c("gg", "ggplot")" to a data.frame

[yutannihilation]

Curious. But I'm not sure if we can fix this on ggplot2's side...

library(ggplot2)
library(magrittr)

my_data <- rnorm(100)

p1 <- qplot(my_data, geom = "histogram")
p1$mapping$x
#> <quosure>
#> expr: ^my_data
#> env:  global

x1 <- rlang::eval_tidy(p1$mapping$x, env = p1$plot_env)
is(x1)
#> [1] "numeric" "vector"

p2 <- my_data %>% qplot(geom = "histogram")
p2$mapping$x
#> <quosure>
#> expr: ^.
#> env:  0x7fc1bd75dd70

x2 <- rlang::eval_tidy(p2$mapping$x, env = p2$plot_env)
is(x2)
#> [1] "list"   "vector"

dput(x2)
#> list(value = structure(list(data = structure(list(), class = "data.frame", row.names = integer(0)), 
#>     layers = list(<environment>), scales = <environment>, mapping = structure(list(
#>         x = ~.), class = "uneval"), theme = list(), coordinates = <environment>, 
#>     facet = <environment>, plot_env = <environment>, labels = list(
#>         y = "", x = ".", weight = "weight")), class = c("gg", 
#> "ggplot")), visible = TRUE)

^{Created on 2019-12-18 by the reprex package (v0.3.0)}

[yutannihilation]

I guess evaluating x and other data in qplot() might fix this issue, but I'm afraid the change would break other things in other places. So, I don't feel this is worth fixing.

[thomasp85]

Yeah, I agree... This is a wontfix especially considering the status of qplot()