[R-pkg-devel] Conditionally register method with generic in other package
For posterity, the solution I employed did not register the method as a formal S3 method. Functionality in package B was unchanged as long as package B was loaded and attached... which was good enough for my purposes.
On Wed, Dec 6, 2017 at 6:45 AM, Joshua Ulrich <josh.m.ulrich at gmail.com> wrote:
I have a feeling I know the answer to this question, but I'm asking with the hope that I learn something new. Package A defines a S3 generic function, "foo()". Package B defines a S3 class "bar", and a foo.bar() method. This method is not strictly necessary for the package to function, and package A has many dependencies. To avoid excessive dependencies, I would like to only register foo.bar() if package A is installed at the time package B is installed. If package A is installed after package B, then warn the user when package B is loaded and/or attached, so they can re-install A and have foo.bar() registered correctly. I could figure out a way to do this manually, but doubt it would be CRAN-approved. What is the recommended way to handle this situation? I've received one suggestion to split B into 2 packages: one without the method, and one with. Are there other alternatives? Thanks, Josh -- Joshua Ulrich | about.me/joshuaulrich FOSS Trading | www.fosstrading.com R/Finance 2018 | www.rinfinance.com
Joshua Ulrich | about.me/joshuaulrich FOSS Trading | www.fosstrading.com R/Finance 2018 | www.rinfinance.com