I don’t frequently use parameters in R Markdown documents. The initial implementation of render() in {emayili} did not cater for them. A small tweak makes it possible though.
You can install the update from GitHub as follows.
remotes::install_github("datawookie/emayili", ref = "v0.5.2")
Then load the package.
library(emayili)
# A couple of options to display message body.
#
options(
envelope.details = TRUE,
envelope.invisible = FALSE
)
Create an empty message object.
msg <- envelope()
Suppose you have the following simple R Markdown document, params.Rmd, which you want to render into the body of an email.
---
title: "Message with Parameter"
output: html_document
params:
value: 13
---
The value is `r params$value`.
We’ll start by rendering it using the default parameter value.
msg %>%
subject("Default parameter value") %>%
render("params.Rmd", include_css = FALSE)
Date: Wed, 31 Jul 2024 11:50:23 GMT
X-Mailer: {emayili}-0.7.18
MIME-Version: 1.0
Subject: Default parameter value
Content-Type: text/html;
charset=utf-8
<html>
<head>
<title>Message with Parameter</title>
</head>
<body>
<div class="container-fluid main-container">
<div id="header">
<h1 class="title toc-ignore">Message with Parameter</h1>
</div>
<p>The value is 13.</p>
</div>
</body>
</html>
As expected, the default value for the parameter comes through.
Now let’s test a different value.
msg %>%
subject("Better parameter value") %>%
render("params.Rmd", params = list(value = 42), include_css = FALSE)
Date: Wed, 31 Jul 2024 11:50:23 GMT
X-Mailer: {emayili}-0.7.18
MIME-Version: 1.0
Subject: Better parameter value
Content-Type: text/html;
charset=utf-8
<html>
<head>
<title>Message with Parameter</title>
</head>
<body>
<div class="container-fluid main-container">
<div id="header">
<h1 class="title toc-ignore">Message with Parameter</h1>
</div>
<p>The value is 42.</p>
</div>
</body>
</html>
🚀 Success: the specified parameter value now appears. If you use parameters in your R Markdown documents, then you can be confident that these will now work in {emayili} too.