CODEWITHSUNDEEP
rggplot2
Tschösi
Tschösi

Reputation: 579

ggplot object value only available after printing it, how do I force it to evaluate

I have a function (not a function that I can modify though) that returns a ggplot2 object, and I would like to access some value of that object. However, the value is NULL, but as soon as I print the object it becomes available.

Here is a minimal example that mimics the behaviour of that function

test_function <- function(test_arg){ 
      ggplot() + annotate("text", x=0, y=0, label= test_arg) 
    }

Now I'd like to extract the value of the label that was set.

r$> result <- test_function("test")
r$> result$layers[[1]]$geom_params$label
NULL

However

r$> print(result)
r$> result$layers[[1]]$geom_params$label
[1] "test"

does work as intended.

How can I get the same result, but without actually printing the ggplot object?

Thanks!

Upvotes: 0

Views: 113

Answers (1)

teunbrand
teunbrand

Reputation: 38023

I think it lives in the aes_params part until the plot gets printed.

library(ggplot2)

test_function <- function(test_arg){ 
  ggplot() + annotate("text", x=0, y=0, label= test_arg) 
} 

result <- test_function("test")

result$layers[[1]]$aes_params$label
#> [1] "test"

Created on 2021-03-19 by the reprex package (v0.3.0)

Upvotes: 1

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