How to pass an unqoted column name to another method?

[holger brandl]

Hi,

I'd like to pass on a bare column name to another method:

plot_hist = function(df, column){
    quoCol= enquo(column)
    
    hist(pull(df, !!quoCol))
}

plot_hist(iris, Petal.Width) ## works as expected

# here another method that internally should call plot_hist:
do_stuff = function (df, column){
    plot_hist(df, column)
    # ... more stuff
}

do_stuff(iris, Petal.Width) ##  does not work but fails with 

Error in overscope_eval_next(overscope, expr) : 
  object 'Petal.Width' not found

plot_hist should stay as it is, but do_stuff needs to be changed somehow, I guess.

What am I doing wrong here? 

Thanks,

best regards,

Holger

[Hadley Wickham]

do_stuff() needs to enquo() and then unquote when calling plot_hist(). (Quasiquotation is sort of infectious)

Hadley

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[Holger Brandl]

Thanks Hadley, 

it works perfectly now.

Best,

Holger

Hadley Wickham <h.wi...@gmail.com> schrieb am Fr., 8. Dez. 2017 um 19:55 Uhr:

do_stuff() needs to enquo() and then unquote when calling plot_hist(). (Quasiquotation is sort of infectious)

Hadley

On Saturday, December 9, 2017, holger brandl <holger...@gmail.com> wrote:

Hi,

I'd like to pass on a bare column name to another method:

plot_hist = function(df, column){
    quoCol= enquo(column)
    
    hist(pull(df, !!quoCol))
}

plot_hist(iris, Petal.Width) ## works as expected

# here another method that internally should call plot_hist:
do_stuff = function (df, column){
    plot_hist(df, column)
    # ... more stuff
}

do_stuff(iris, Petal.Width) ##  does not work but fails with 

Error in overscope_eval_next(overscope, expr) : 
  object 'Petal.Width' not found

plot_hist should stay as it is, but do_stuff needs to be changed somehow, I guess.

What am I doing wrong here? 

Thanks,

best regards,

Holger

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