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Authorize ladder

Source: R/api_slides_auth.R
ladder_auth.Rd

Authorize ladder to view and manage your presentations. This function is a wrapper around gargle::token_fetch().

By default, you are directed to a web browser, asked to sign in to your Google account, and to grant ladder permission to operate on your behalf with Google Slides. By default, with your permission, these user credentials are cached in a folder below your home directory, from where they can be automatically refreshed, as necessary. Storage at the user level means the same token can be used across multiple projects and tokens are less likely to be synced to the cloud by accident.

Usage

ladder_auth(
  email = gargle::gargle_oauth_email(),
  path = NULL,
  subject = NULL,
  scopes = c("https://www.googleapis.com/auth/drive.file",
    "https://www.googleapis.com/auth/presentations.currentonly"),
  cache = gargle::gargle_oauth_cache(),
  use_oob = gargle::gargle_oob_default(),
  token = NULL
)

Arguments

email

Optional. If specified, email can take several different forms:

  • "jane@gmail.com", i.e. an actual email address. This allows the user to target a specific Google identity. If specified, this is used for token lookup, i.e. to determine if a suitable token is already available in the cache. If no such token is found, email is used to pre-select the targeted Google identity in the OAuth chooser. (Note, however, that the email associated with a token when it's cached is always determined from the token itself, never from this argument).

  • "*@example.com", i.e. a domain-only glob pattern. This can be helpful if you need code that "just works" for both alice@example.com and bob@example.com.

  • TRUE means that you are approving email auto-discovery. If exactly one matching token is found in the cache, it will be used.

  • FALSE or NA mean that you want to ignore the token cache and force a new OAuth dance in the browser.

Defaults to the option named "gargle_oauth_email", retrieved by gargle_oauth_email() (unless a wrapper package implements different default behavior).

path

JSON identifying the service account, in one of the forms supported for the txt argument of jsonlite::fromJSON() (typically, a file path or JSON string).

subject

An optional subject claim. Specify this if you wish to use the service account represented by path to impersonate the subject, who is a normal user. Before this can work, an administrator must grant the service account domain-wide authority. Identify the user to impersonate via their email, e.g. subject = "user@example.com". Note that gargle automatically adds the non-sensitive "https://www.googleapis.com/auth/userinfo.email" scope, so this scope must be enabled for the service account, along with any other scopes being requested.

scopes

A character vector of scopes to request. Pick from those listed at https://developers.google.com/identity/protocols/oauth2/scopes.

cache

Specifies the OAuth token cache. Defaults to the option named "gargle_oauth_cache", retrieved via gargle_oauth_cache().

use_oob

Whether to use out-of-band authentication (or, perhaps, a variant implemented by gargle and known as "pseudo-OOB") when first acquiring the token. Defaults to the value returned by gargle_oob_default(). Note that (pseudo-)OOB auth only affects the initial OAuth dance. If we retrieve (and possibly refresh) a cached token, use_oob has no effect.

If the OAuth client is provided implicitly by a wrapper package, its type probably defaults to the value returned by gargle_oauth_client_type(). You can take control of the client type by setting options(gargle_oauth_client_type = "web") or options(gargle_oauth_client_type = "installed").

token

A token with class Token2.0 or an object of httr's class request, i.e. a token that has been prepared with httr::config() and has a Token2.0 in the auth_token component.

Details

Most users, most of the time, do not need to call ladder_auth() explicitly – it is triggered by the first action that requires authorization. Even when called, the default arguments often suffice.

However, when necessary, ladder_auth() allows the user to explicitly:

  • Declare which Google identity to use, via an email specification.

  • Use a service account token or workload identity federation via path.

  • Bring your own token.

  • Customize scopes.

  • Use a non-default cache folder or turn caching off.

  • Explicitly request out-of-band (OOB) auth via use_oob.

If you are interacting with R within a browser (applies to RStudio Server, Posit Workbench, Posit Cloud, and Google Colaboratory), you need OOB auth or the pseudo-OOB variant. If this does not happen automatically, you can request it explicitly with use_oob = TRUE or, more persistently, by setting an option via options(gargle_oob_default = TRUE).

The choice between conventional OOB or pseudo-OOB auth is determined by the type of OAuth client. If the client is of the "installed" type, use_oob = TRUE results in conventional OOB auth. If the client is of the "web" type, use_oob = TRUE results in pseudo-OOB auth. Packages that provide a built-in OAuth client can usually detect which type of client to use. But if you need to set this explicitly, use the "gargle_oauth_client_type" option:

options(gargle_oauth_client_type = "web")       # pseudo-OOB
# or, alternatively
options(gargle_oauth_client_type = "installed") # conventional OOB

For details on the many ways to find a token, see gargle::token_fetch(). For deeper control over auth, use ladder_auth_configure() to bring your own OAuth client or API key. To learn more about gargle options, see gargle::gargle_options.

See also

Other auth functions: ladder_auth_configure(), ladder_deauth()

Examples

if (FALSE) { # rlang::is_interactive()
# load/refresh existing credentials, if available
# otherwise, go to browser for authentication and authorization
ladder_auth()

# see user associated with current token
ladder_user()

# force use of a token associated with a specific email
ladder_auth(email = "jenny@example.com")
ladder_user()

# force the OAuth web dance
ladder_auth(email = NA)

# use a 'read only' scope, so it's impossible to edit or delete files
ladder_auth(scopes = "slides.readonly")

# use a service account token
ladder_auth(path = "foofy-83ee9e7c9c48.json")
}