R htmltools browsable HTML does not view without explicit print() - html

Question

I can create HTML code in R that is wrapped with attributes using htmltools package functions. This allows html to be rendered from the console (a browser window is automatically launched) as well as in R Markdown and Quarto documents. But I can't get this to work without an explicit print(). How to make it work with an implicit print? Here is a minimal working example.
require(htmltools)
x <- readLines(textConnection('
<table>
<tr>
<th>Company</th>
<th>Contact</th>
<th>Country</th>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Maria Anders</td>
<td>Germany</td>
</tr>
<tr>
<td>Centro comercial Moctezuma</td>
<td>Francisco Chang</td>
<td>Mexico</td>
</tr>
</table>'))
print.ctest <- function(x) browsable(HTML(x))
class(x) <- 'ctest'
print(x) # opens browser
x # does nothing

Answer 1

If an object is called by its name it uses the default print method for the respective class. Convert x to HTML and call x afterwards it will implicit call print and launch the correct device ( browser)
require(htmltools)
x <- readLines(textConnection('
<table>
<tr>
<th>Company</th>
<th>Contact</th>
<th>Country</th>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Maria Anders</td>
<td>Germany</td>
</tr>
<tr>
<td>Centro comercial Moctezuma</td>
<td>Francisco Chang</td>
<td>Mexico</td>
</tr>
</table>'))
class(x) # [1] "character"
x # prints character in console
x_1 <- browsable(HTML(x))
class(x_1) # [1] "html" "character"
x_1 # shows HTML in browser without explicit print
Edit, to get the implicit print call to work with our custom class use registerS3method to link the method to the class
## change class
class(x) <- 'ctest'
## register its method
registerS3method("print", "ctest",function(x) {print(browsable(HTML(x)))} )
# now the class is recognized and our registered Method is used.
x