Mutate expression block constructor

This block allows to add new variables and preserve existing ones using R expressions (see dplyr::mutate()). Changes are applied after clicking the submit button.

Usage

new_mutate_expr_block(exprs = list(new_col = "1"), by = character(), ...)

Arguments

exprs

Reactive expression returning character vector of expressions

by

Character vector of column names for grouping. Default is empty.

...

Additional arguments forwarded to blockr.core::new_block()

Value

A block object for mutate operations

See also

blockr.core::new_transform_block()

Examples

# Create a mutate expression block
new_mutate_expr_block(exprs = list(mpg_squared = "mpg^2"))
#> <mutate_expr_block<transform_block<block>>>
#> Name: "Mutate expr"
#> Data inputs: "data"
#> Initial block state:
#>  $ exprs:List of 1
#>   ..$ mpg_squared: chr "mpg^2"
#>  $ by   : chr(0)
#> Constructor: blockr.dplyr::new_mutate_expr_block()

if (interactive()) {
  # Basic usage with mtcars datase
  library(blockr.core)
  serve(new_mutate_expr_block(), data = list(data = mtcars))

  # With a custom dataset
  df <- data.frame(x = 1:5, check.names = FALSE)
  df$`2025 Sales` <- letters[1:5]
  serve(new_mutate_expr_block(), data = list(data = df))
}