Collect grades from feedback YAML

[thereseanders]

There are at least two alternative approaches for collecting grades from the YAML of the standardized feedback forms. Both options below first use get_file() to retrieve the content of the .Rmd via the Contents API: "---\ntitle: \"Reviewer feedback for HW1\"\noutput: github_document\nparams:\n q1_score: 5\n q2_score: 3\n q3_score: 3\n q4_score: 5\n q5_score: 10\n---\n\n\n## Feedback\n\n1. Place Question 1 text here.\n\nYour response goes here...\n\n2. Place Question 2 text here.\n\nYour response goes here...\n\n3. Place Question 3 text here.\n\nYour response goes here...\n\n4. Place Question 4 text here.\n\nYour response goes here...\n\n5. Place Question 5 text here.\n\nYour response goes here...\n"

One can extract the grades (i.e. 5, 3, 3, 5, 10) by:

A) Using string operations to extract the content of the grade tags from the raw content above.

OR

B) Using tempfile() to create a temporary .Rmd file and then extract the information via rmarkdown::yaml_front_matter().

Option B) seems preferable, because rmarkdown::yaml_front_matter() automatically outputs a list, but it also requires a potentially large number of temporary .Rmd files, depending on the number of students and reviews.

@mine-cetinkaya-rundel @rundel do you have any thoughts on which route to go with?

[mine-cetinkaya-rundel]

Why is the temporary file needed for option B? Is it not possible to extract it out without the temporary file? I imagine not, but I'm not sure why off the top of my head.

[thereseanders]

The return of get_file() is a character string with the raw file contents. rmarkdown::yaml_front_matter() expects a .Rmd file as input and can therefore not directly be called on the return of get_file().

Here is the code snipped implementing option B) in the current version of peer_collect_score():

feedback = purrr::safely(get_file)(repo, file)

if (succeeded(feedback)) {

  tempf = tempfile(fileext = ".Rmd")
  zz = file(tempf, "w")
  cat(feedback[[1]], file = zz)
  close(zz)
  scores = rmarkdown::yaml_front_matter(tempf)$params
  unlink(tempf)

} else {
  usethis::ui_oops(
    "Cannot locate file {usethis::ui_value(file)} on repo {usethis::ui_value(repo)}."
  )
}

[rundel]

I don't think a tempfile is needed here - this delves a bit into the weirdness of files vs connections in R but I think something like

txt = ghclass::repo_get_file()
tc = textConnection(txt)
rmarkdown::yaml_front_matter(tc)

should work.

[thereseanders]

Oh thats a great solution and it works! Thank you.