Understanding the Problem with Formattable() and Column Names

The formattable() function in R is a powerful tool for creating interactive tables in Shiny applications. One of its key features is the ability to format column names and values. However, when dealing with duplicate column names, the function can behave unexpectedly.

In this article, we will delve into the issue with column names and explore solutions to achieve the desired output.

The Issue

The problem arises when trying to rename a column that already has a similar name. In the provided example, the n.1 column is renamed to n, but its corresponding value is still displayed as n.1. This issue occurs because only the first column with a duplicate name is displayed.

The Solution

To resolve this problem, we can use the check.names argument in the formattable() function. By setting it to FALSE, we allow the function to display both columns even if their names are similar.

Here’s an updated example:

library(formattable)

df <- data.frame(
  ID     = LETTERS[1:4], 
  `2018` = c(0.5,0.9,0.8,0.4), 
  n      = c(88,44,55,66), 
  `2019` = c(0.9,0.8,0.7,0.4), 
  `n `   = c(78,84,54,25), 
  check.names = FALSE

formattable(df,
            align=c("l", "r", "l", "r", "l"),
            list(
              `2018` = function(x) percent(x, digits = 1),
              `2019` = function(x) percent(x, digits = 1)
            )
)

Why Does This Work?

By setting check.names = FALSE, we tell the formattable() function to ignore the standard naming conventions for data frames. This allows us to display both columns even if their names are similar.

However, it’s essential to note that using check.names = FALSE can lead to inconsistencies in the output and may affect the overall appearance of the table. It’s crucial to weigh the benefits against the potential drawbacks before deciding to use this approach.

Alternative Solutions

If you prefer not to use check.names = FALSE, there are alternative solutions to achieve similar results:

1. Add a space to the column name: As mentioned in the original question, adding a space to the column name (e.g., n) can prevent duplicate names from causing issues.

df <- data.frame( ID = LETTERS[1:4], 2018 = c(0.5,0.9,0.8,0.4), n = c(88,44,55,66), 2019 = c(0.9,0.8,0.7,0.4), n = c(78,84,54,25) )

formattable(df, align=c(“l”, “r”, “l”, “r”, “l”), list( 2018 = function(x) percent(x, digits = 1), 2019 = function(x) percent(x, digits = 1) ) )

2.  **Use a different data type**: If possible, consider using a different data type for the column with duplicate names.

## Conclusion

The issue with `formattable()` and column names can be tricky to resolve, but there are several solutions available. By understanding the underlying mechanics of the function and exploring alternative approaches, you can achieve the desired output and create high-quality tables in your Shiny applications.

Last modified on 2024-01-18