Writing a package function that uses a dbplyr call to tbl() - r

Question

I have a simple function that should fetch a table using a DBI::dbConnect() connection. I am having trouble with the call to tbl() that works fine in an interactive session.
My function:
a2_db_read <- function(con, tbl_name, schema = "dbo"){
if(schema == "dbo"){
dplyr::tbl(con, tbl_name)
}
else{
dplyr::tbl(con, dbplyr::in_schema(schema, tbl_name))
}
}
If I make the call dplyr::tbl() I get:
Error in UseMethod("tbl") :
no applicable method for 'tbl' applied to an object of class "Microsoft SQL Server"
If I make the call dbplyr::tbl() I get:
a2_db_read(a2_con_uat, "AVL Data")
Error: 'tbl' is not an exported object from 'namespace:dbplyr'
How can I get that call to succeed in a function? My package Imports is:
Imports:
DBI,
dbplyr,
dplyr,
ggplot2,
odbc

Answer 1

I got it working with dplyr::tbl(), the correct usage.
The problem was that my connection was stored as an object in a package when in fact the connection needs to be made every time I restart R.
On a fresh R environment, the stored stale connection caused the error:
Error in UseMethod("tbl") :
no applicable method for 'tbl' applied to an object of class "Microsoft SQL Server"
When I regenerated the connection, it worked.