How to specify column parameters programmatically?

Question

For the qic() function, how does one specify columns of the input data frame that are stored in string variables?

Below I attempt multiple ways to pass the "y" parameter. Given that qicharts2 is based on ggplot2 I tried some options resembling quoting for ggplot2. All failed.

my_fun <- function(y){
  require(qicharts2)

  qic(x        = i, 
      y        = .data[[y]],  # Hoping it works like ggplot2.
      n        = n, 
      data     = nhs_accidents, 
      chart    = 'p',
      title    = 'Proportion of patients seen within 4 hours',
      ylab     = NULL,
      xlab     = 'Week #')
}

my_var <- "r"
my_fun(my_var)

Error: ! Can't subset .data outside of a data mask context. Run rlang::last_trace() to see where the error occurred.

Here are some other ways I tried to define the parameter along with the errors.

y = as.symbol(my_var)

Error in stats::complete.cases(y, n) : invalid 'type' (symbol) of argument

y = {{my_var}}

Error in if (y.name == "NULL") y.name <- deparse(substitute(x)) : the condition has length > 1

y = rlang::as_label(my_var)

Error in stats::complete.cases(y, n) : not all arguments have the same length

Answer 1

This works for me:

my_fun <- function(y_){
  require(qicharts2)
  qic(x        = i, 
      y        = eval(parse(text = y_)),
      n        = n, 
      data     = nhs_accidents, 
      chart    = 'p',
      title    = 'Proportion of patients seen within 4 hours',
      ylab     = NULL,
      xlab     = 'Week #')
}

my_var <- "r"

my_fun(my_var)