pipe (%>%) ggplot2 like ggvis - r

Question

When I integrate tables and figures in a document using knitr, adding the code makes it more reproducible and interesting.
Often a combination of dplyr and ggvis can make a plot that has relatively legible code (using the magrittr pipe operator %>).
mtcars %>%
group_by(cyl, am) %>%
summarise( weight = mean(wt) ) %>%
ggvis(x=~am, y=~weight, fill=~cyl) %>%
layer_bars()
The problem is that the ggvis plot:
does not look quite as as pretty as the ggplot2 plot (I know, factoring of cyl):
However, for ggplot2 we need:
mtcars %>%
group_by(am, cyl) %>%
summarise( weight = mean(wt) ) %>%
ggplot( aes(x=am, y=weight, fill=cyl) ) +
geom_bar(stat='identity')
My problem is that this switches from %>% to + for piping. I know this is a very minor itch, but I would much prefer to use:
mtcars %>%
group_by(am, cyl) %>%
summarise( weight = mean(wt) ) %>%
ggplot( aes(x=am, y=weight, fill=cyl) ) %>%
geom_bar(stat='identity')
Is there a way to modify the behaviour of ggplot2 so that this would work?
ps. I don't like the idea of using magrittr's add() since this again make the code more complicated to read.

Answer 1

Since it would be too long to expand in the comments, and based on your answer I am not sure if you tried the bit of code I provided and it didn't work or you tried previously and didn't manage
geom_barw<-function(DF,x,y,fill,stat){
require(ggplot2)
p<-ggplot(DF,aes_string(x=x,y=y,fill=fill)) + geom_bar(stat=stat)
return(p)
}
library(magrittr)
library(dplyr)
library(ggplot2)
mtcars %>%
group_by(cyl, am) %>%
summarise( weight = mean(wt) ) %>%
geom_barw(x='am', y='weight', fill='cyl', stat='identity')
This works for me with:
dplyr_0.4.2 ggplot2_2.1.0 magrittr_1.5
Of course geom_barw could be modified so you don't need to use the quotes anymore.
EDIT: There should be more elegant and safer way with lazy (see the lazyeval package), but a very quick adaptation would be to use substitute (as pointed by Axeman - however without the deparse part):
geom_barw<-function(DF,x,y,fill,stat){
require(ggplot2)
x<-substitute(x)
y<-substitute(y)
fill<-substitute(fill)
p<- ggplot(DF,aes_string(x=x,y=y,fill=fill))
p<- p + geom_bar(stat=stat)
return(p)
}