We can use rlang::parse_quosure()
together with !!
(bang bang) to produce the same result:
Note that parse_quosure()
was soft-deprecated and renamed to parse_quo()
in rlang 0.2.0
per its documentation. If we use parse_quo()
, we need to specify the environment for the quosures e.g. parse_quo(input_from_shiny, env = caller_env())
library(rlang)
library(tidyverse)
input_from_shiny <- "Petal.ratio = Petal.Length/Petal.Width"
iris_mutated <- iris %>% mutate_(input_from_shiny)
iris_mutated2 <- iris %>%
mutate(!!parse_quosure(input_from_shiny))
head(iris_mutated2)
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> 1 5.1 3.5 1.4 0.2 setosa
#> 2 4.9 3.0 1.4 0.2 setosa
#> 3 4.7 3.2 1.3 0.2 setosa
#> 4 4.6 3.1 1.5 0.2 setosa
#> 5 5.0 3.6 1.4 0.2 setosa
#> 6 5.4 3.9 1.7 0.4 setosa
#> Petal.ratio = Petal.Length/Petal.Width
#> 1 7.00
#> 2 7.00
#> 3 6.50
#> 4 7.50
#> 5 7.00
#> 6 4.25
identical(iris_mutated, iris_mutated2)
#> [1] TRUE
Edit: to separate LHS & RHS
lhs <- "Petal.ratio"
rhs <- "Petal.Length/Petal.Width"
iris_mutated3 <- iris %>%
mutate(!!lhs := !!parse_quosure(rhs))
head(iris_mutated3)
> head(iris_mutated3)
Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1 5.1 3.5 1.4 0.2 setosa
2 4.9 3.0 1.4 0.2 setosa
3 4.7 3.2 1.3 0.2 setosa
4 4.6 3.1 1.5 0.2 setosa
5 5.0 3.6 1.4 0.2 setosa
6 5.4 3.9 1.7 0.4 setosa
Petal.ratio
1 7.00
2 7.00
3 6.50
4 7.50
5 7.00
6 4.25
Created on 2018-03-24 by the reprex package (v0.2.0).
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