Messages and errors in googledrive • googledrive

library(googledrive)

Things I do in a hidden chunk here, to aid exposition about internal tooling:

“Export” the internal helpers covered below
(Attempt to) auth as the service account we use when rendering documentation

User-facing messages

Everything should be emitted by helpers in utils-ui.R: specifically, drive_bullets() (and, for errors, drive_abort()). These helpers are all wrappers around cli functions, such as cli::cli_bullets().

These may not demo well via pkgdown, but the interactive experience is nice.

drive_bullets(c(
        "noindent",
  " " = "indent",
  "*" = "bullet",
  ">" = "arrow",
  "v" = "success",
  "x" = "danger",
  "!" = "warning",
  "i" = "info"
))
#> noindent
#>   indent
#> • bullet
#> → arrow
#> ✔ success
#> ✖ danger
#> ! warning
#> ℹ info

The helpers encourage consistent styling and make it possible to selectively silence messages coming from googledrive. The googledrive message helpers:

Use the cli package to get interpolation, inline markup, and pluralization.
Eventually route through rlang::inform(), which is important because inform() prints to standard output in interactive sessions. This means that informational messages won’t have the same “look” as errors and can generally be more stylish, at least in IDEs like RStudio.
Use some googledrive-wide style choices, such as:
- The custom .drivepath style is like cli’s inline .file style, except cyan instead of blue.
- The built-in .field style is tweaked to be flanked by single quotes in a no-color situation.
- The typical “*” bullet isn’t colored, since we’ve got so much other color going on.
Are under the control of the googledrive_quiet option. If it’s unset, the default is to show messages (unless we’re testing, i.e. the environment variable TESTTHAT is "true"). Doing options(googledrive_quiet = TRUE) will suppress messages. There are withr-style convenience helpers: local_drive_quiet() and with_drive_quiet().

Inline styling

How we use the inline classes:

.drivepath for the name or, occasionally, the (partial) path of a Drive file
.field for the value of an argument, e.g. a MIME type
.code for a column in a data frame and for reserved words, such as NULL, TRUE, and NA
.arg, .fun, .path, .cls, .url for their usual purpose

drive_bullets(c(
  "We need to talk about the {.arg foofy} argument to {.fun blarg}",
  "You provided {.field a_very_weird_value} and I suspect you're confused \\
   about something"
))
#> We need to talk about the `foofy` argument to `blarg()`
#> You provided a_very_weird_value and I suspect you're confused about something

Most relevant cli docs:

Bullets

I use the different bullet points in drive_bullets() to convey a mood.

Exclamation mark "!": I’m not throwing an error or warning, but I want to get the user’s attention, because it seems likely (but not certain) that they misunderstand something about googledrive or Google Drive or their Drive files. Examples:

drive_bullets(c(
  "!" = "Ignoring {.arg type}. Only consulted for native Google file types.",
  " " = "MIME type of {.arg file}: {.field mime_type}."
))
#> ! Ignoring `type`. Only consulted for native Google file types.
#>   MIME type of `file`: mime_type.

drive_bullets(c(
  "!" = "Currently only fields for the {.field files} resource can be \\
         checked for validity.",
  " " = "Nothing done."
))
#> ! Currently only fields for the files resource can be checked for validity.
#>   Nothing done.

drive_bullets(c(
  "!" = "No updates specified."
))
#> ! No updates specified.

drive_bullets(c(
  "!" = "No such file to delete."
))
#> ! No such file to delete.

Information “i”: I’m just keeping you informed of how my work is going.

drive_bullets(c(
  "i" = "No pre-existing file at this filepath. Calling \\
         {.fun drive_upload}."
))
#> ℹ No pre-existing file at this filepath. Calling `drive_upload()`.

drive_bullets(c(
  "i" = "Pre-existing file at this filepath. Calling \\
         {.fun drive_update}."
))
#> ℹ Pre-existing file at this filepath. Calling `drive_update()`.

drive_bullets(c(
  "i" = "Not logged in as any specific Google user."
))
#> ℹ Not logged in as any specific Google user.

In cases where we determine there is nothing we can or should do, sometimes I use "!" and sometimes I use "i". It depends on whether it feels like the user could or should have known that no work would be possible or needed.

Programmatic generation of bullets

Often we need to create bullets from an R object, such as a character vector or a dribble. What needs to happen:

Map a cli-using string template over the object to get a character vector
Truncate this vector in an aesthetically pleasing way
Apply names to this vector to get the desired bullet points

gargle_map_cli() is a new generic in gargle that turns an object into a vector of strings with cli markup. Currently gargle exports methods for character (and NULL and a default) and googlesheets4 defines a method for dribble. This is likely to be replaced by something in cli itself in due course.

gargle_map_cli(letters[1:3])
#> [1] "{.field a}" "{.field b}" "{.field c}"

By default gargle_map_cli.character() just applies the .field style, i.e. the template is "{.field <<x>>}". But the template can be customized, if you need something else. Note that we use non-standard glue delimiters (<< and >>, by default), because we are interpolating into a string with glue/cli markup, where {} has the usual meaning.

gargle_map_cli(letters[4:6], template = "how about a path {.path <<x>>}?")
#> [1] "how about a path {.path d}?" "how about a path {.path e}?"
#> [3] "how about a path {.path f}?"

The gargle_map_cli.dribble() method makes a cli-marked up string for each row of the dribble, i.e. for each Drive file.

dat <- drive_find(n_max = 5)
#> Error in `drive_auth()`:
#> ! Can't get Google credentials.
#> ℹ Are you running googledrive in a non-interactive session? Consider:
#> • Call `drive_deauth()` to prevent the attempt to get credentials.
#> • Call `drive_auth()` directly with all necessary specifics.
#> ℹ See gargle's "Non-interactive auth" vignette for more details:
#> ℹ <https://gargle.r-lib.org/articles/non-interactive-auth.html>
gargle_map_cli(dat)
#> Error: object 'dat' not found

gargle_map_cli.dribble() also allows a custom template, but it’s a more complicated and less common situation than for character. We won’t get into that here. (I don’t consider the dribble styling to be finalized yet.)

The result of gargle_map_cli() then gets processed with gargle::bulletize(), which adds the bullet-specifying names and does aesthetically pleasing truncation.

bulletize(gargle_map_cli(letters))
#>               *               *               *               *               * 
#>    "{.field a}"    "{.field b}"    "{.field c}"    "{.field d}"    "{.field e}" 
#>                 
#> "… and 21 more"

bulletize(gargle_map_cli(letters), bullet = "x", n_show = 2)
#>               x               x                 
#>    "{.field a}"    "{.field b}" "… and 24 more"

drive_bullets(c(
  "These are surprising things:",
  bulletize(gargle_map_cli(letters), bullet = "!")
))
#> These are surprising things:
#> ! a
#> ! b
#> ! c
#> ! d
#> ! e
#>   … and 21 more

dat <- drive_find(n_max = 10)
#> Error in `drive_auth()`:
#> ! Can't get Google credentials.
#> ℹ Are you running googledrive in a non-interactive session? Consider:
#> • Call `drive_deauth()` to prevent the attempt to get credentials.
#> • Call `drive_auth()` directly with all necessary specifics.
#> ℹ See gargle's "Non-interactive auth" vignette for more details:
#> ℹ <https://gargle.r-lib.org/articles/non-interactive-auth.html>

drive_bullets(c(
  "Some Drive files:",
  bulletize(gargle_map_cli(dat))
))
#> Error: object 'dat' not found

It’s conceivable that cli will gain a better way of vectorization, but this works for now.

Known dysfunction: it’s inefficient to gargle_map_cli() over the whole object, then truncate with bulletize(). But it’s easy. There are contexts, like tibble printing, where formatting stuff that will never see the light of day is really punishing. But I’m not sure I really have to worry about that.

Errors

I am currently using cli::cli_abort(), which is present in the dev version of cli (as of late May 2021, cli version 2.5.0.9000).

It’s wrapped as drive_abort(), for the same reason as drive_bullets(), namely to apply some package-wide style tweaks.

The mechanics of drive_abort() usage are basically the same as drive_bullets().