Using restore()

As with the previous exercise, it is recommended that you fork the repository to your GitHub account and clone it to your local machine to follow along with the examples. This will allow the course facilitators to see your work, provide feedback, and troubleshoot with you as needed.

If you’re not familiar with using git and GitHub, you can skip the forking and cloning steps and instead download a zip file of the repository.

Restore a {renv} Project

The exercises for initiating and snapshotting a project can be found in the restore-exercises folder of the intro-to-renv-exercises repo.

Exercise Notes

Restoring a project library from a renv.lock file can generally be accomplished in just two steps:

1. Open the RStudio .RProj file.
2. Run renv::restore().

You could technically complete just these two steps for this exercise, and you would essentially be finished. However, the exercise is designed to help you understand the process of restoring a project library, and to help you see what happens when your project library does not match the required packages laid out in renv.lock file.

Instructions

IMPORTANT: This exercise expects you have version 4.4.X of R installed. If you have a different version, please install the correct version before starting the exercise. Step 5 will most likely fail if you have an older version of R installed. You can still read along, and then watch the solution video.

1. Open the restore-exercises.Rproj file.

   • Upon opening, you should be greeted with a message similar to this:

     # Bootstrapping renv 1.0.7 ---------------------------------------------------
     - Downloading renv ... OK
     - Installing renv  ... OK
     
     - Project '~/Desktop/introduction-to-renv-exercises/restore-exercises' loaded. [renv 1.0.7]
     - One or more packages recorded in the lockfile are not installed.
     - Use `renv::status()` for more details.

2. At the console, run the command renv::status().
   • What is out of sync and why?
3. At the console, run the command renv::dependencies(). For better formatting, you can run View(renv::dependencies()).

   • What packages do you see listed as direct dependencies?

   • The Source column indicates which files use these packages. Knowing this, can you list the package dependencies by file?

   • Note: some versions of Quarto/RStudio may present you with the warning message below. If this occurs, then install the package, and run renv::dependencies() again.

     The 'yaml' package is required to parse dependencies within R Markdown files. Consider installing it with install.packages("yaml")." 

4. Open the presentation.rmd file.
   • Note: RStudio may prompt you to install several packages in a yellow highlighted bar. You can ignore this request. A later step will address this.
   • {rmarkdown} was listed as a dependency from this file, but there is not actually a call to the package in the file. Why do you think this is?
5. We want to simulate running someone else’s analysis without first installing the same packages as them: try to Render¹ the presentation.rmd file.
   • You will be prompted to install some packages in a pop-up window. This is to install the {rmarkdown} package and its dependencies. Accept the prompt.
   • The {rmarkdown} package and its dependencies should install, but the rendering still fails. Why do you think this is? Take a careful look at the error message, and align it with the content of the presentation.rmd file.
6. We will now need to install all R packages required for this exercise. Run the command renv::restore().
   • What happens?
   • If prompted with the question “Do you want to proceed? [Y/n]:”, type Y and press Enter.”
7. Open the billboard_100.R file, and run the code by pressing the Source button near the top right hand corner of the script.
   • This should create the top_billboard_rankings.rds file, needed in the next step.
8. Try to render the presentation.rmd file.
   • What happens?
9. Close the project restore-exercises.Rproj.

Congrats! You have restored someone else’s project and successfully rendered their analysis.

Footnotes

1. “Rendering” an RMarkdown .rmd, Quarto .qmd, or similar file simply means you are generating the output file (e.g., .html, .pdf, etc.) from the source file. In RStudio, you can do this by clicking the “Knit” or “Render” button depending on your file type and version of RStudio.