Send email with gmailr

In gmailr: Access the 'Gmail' 'RESTful' API

Scenario: BYO encrypted user token

library(shiny)

can_decrypt <- gargle::secret_has_key("GMAILR_DEPLOY_DEMO_KEY")

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  eval = can_decrypt
)

cat("*Decryption key is unavailable, so no code will be evaluated.*")

The following chunk reads the stored token from file, using the environment variable "GMAILR_DEPLOY_DEMO_KEY" to decrypt it, and tells gmailr to use it.

library(gmailr)

try(
  gm_auth(token = gm_token_read(
    ".secrets/gmailr-token.rds",
    key = "GMAILR_DEPLOY_DEMO_KEY"
  ))
)

We wrap that in try() to guard against the scenario where the token can be decrypted, but then it can't be refreshed. If auth has been successful, the gm_profile() call below reveals details about the account associated with the cached token. If auth has not been successful, gm_profile() will throw an error. Other functions that can be helpful for confirming the validity of a re-loaded token are gargle::token_tokeninfo() and gargle::token_userinfo().

This Shiny document sends email from this account:

(whoami <- gm_profile())

Here's the function that takes the inputs for To:, Subject:, and Body: and sends an email when the user clicks "Send mail":

send_email <- function() {
  gm_mime() |>
    gm_to(input$field_to) |>
    gm_from(whoami$emailAddress) |>
    gm_subject(input$field_subject) |>
    gm_text_body(input$field_body) |>
    gm_send_message()
}

Send an Email

textInput("field_to", "To:", placeholder = "[e-mail]")
textInput("field_subject", "Subject:", placeholder = "fascinating email subject")
textAreaInput("field_body", "Body:", placeholder = "riveting, but short, email body")

actionButton("btn", "Send mail")

observeEvent(input$btn, {
  output$log_sent_email <- renderPrint({
    cat("Sending email...\n")
    cat(format(send_email()))
  })
})
verbatimTextOutput("log_sent_email")

Preview Email

renderPrint({
  cat(
    "To: ", input$field_to,
    "\nSubject: ", input$field_subject,
    "\n\n", input$field_body,
    sep = ""
  )
})

gmailr documentation built on July 9, 2023, 5:07 p.m.