Custom PowerPoints Using {officer}

From a purely design perspective, Quarto’s standard PowerPoint output
falls short. It is limited to
seven layout
options, with the most complex being “Two Content.” The {officer} R
package offers a powerful alternative for those seeking full control and
customisation.

Why PowerPoint?

At work, I use a Linux operating system (OS), and at home, I use macOS.
Within my little bubble, it’s easy to forget how much of the market
share Microsoft still holds. It’s estimated that around 70% of the
desktop operating system market share belongs to
Microsoft.
Many of the clients I work with prefer Microsoft outputs, such as
PowerPoint, over HTML or PDF. Aside from company alignment with
Microsoft, there are a few practical reasons why using PowerPoint with
Quarto can be advantageous:

No need to be a CSS / LaTeX whizz-kid to produce professional-looking
slides
Possible (and easy) to edit after rendering the doc!

What is {officer}?

From
davidgohel.github.io/officer

The officer package lets R users manipulate Word (.docx) and
PowerPoint (*.pptx) documents. In short, one can add images, tables
and text into documents from R. An initial document can be provided;
contents, styles and properties of the original document will then be
available.

This means for this workflow, Quarto is sidestepped altogether, and we
focus entirely on R scripts and R coding.

How?

There are a few ways to use {officer} – I’ll walk through the approach
that I’ve found to be most effective.

Layout templates

First – you’ll need a PowerPoint presentation that contains template
layout slides. There are no limits to these slides, the format can be as
custom as you like and there can be as many layouts as you want.
Remember – this file doesn’t need any actual slides, it only needs
layouts! To create a layout:

Enter “Slide Master” mode
Add any content (headers, footers, styling etc) you want to appear
on each slide to the “Slide Master”
Create a new Layout Slide

To insert content from R, the easiest way is via placeholders. These can
be text, tables, images and more. To add a placeholder:

Click “Insert Placeholder” and choose the content type
If it’s a text placeholder, you can customise the formatting of the
text

You can see below that I’ve added some basic Jumping River styling to
mine, and added two placeholders; a text placeholder for a title and an
image placeholder for a plot.

In order to access these placeholders easily from R, it’s better to
rename them:

Home tab
Click the “Select” dropdown
Click “Selection pane”
Select your placeholder and rename

Here I’ve named my image placeholder “plot”, and my text placeholder
for the slide title, “title”. Note that it’s also a good idea to name
your layout – just right click and hit rename. In this demo I’ve just
left it as “Title Slide”.

The R code

Now that I’ve got my template set up, the rest is in R. First, we load
{officer} and read the PowerPoint document in as an R object.

library("officer")
doc = read_pptx("mytemplate.pptx")

If you’ve forgotten your layout / placeholder names, access them through
layout_summary() and layout_properties()

layout_summary(doc)
layout_properties(doc, layout = "Title Slide", master = "Office Theme")

Before any content can be added, content is needed! Let’s use the
{palmerpenguins} package to create a simple plot of “Adelie” penguins
data

library("palmerpenguins")
library("dplyr")
library("ggplot2")

adelie_plot = penguins |>
 filter(species == "Adelie") |>
 ggplot(aes(x = bill_length_mm, y = flipper_length_mm)) +
 geom_point() +
 theme_linedraw() +
 theme(
 # Make the background transparent
 plot.background = element_rect(fill = "transparent", colour = NA),
 # Match the panel colour to the slide
 panel.background = element_rect(fill = "#F1EADE", colour = NA)) +
 labs(
 x = "Bill Length (mm)",
 y = "Flipper Length (mm)")

I can add empty slides to the document using the add_slide() function.
Here I simply choose a layout from my .pptx file to use.

doc = add_slide(doc, layout = "Jumping Rivers", master = "Office Theme")
doc

Then, using the ph_with() function, I can insert R objects into my
placeholders by name

doc = ph_with(
 doc,
 value = "Adelie",
 location = ph_location_label("title")
)
# Add the plot
doc = ph_with(
 doc,
 value = adelie_plot,
 location = ph_location_label("myplot")
)

To create the PowerPoint, use print()

print(doc, "penguins.pptx")

And there we have it! I’ve used only two placeholders here to keep the
example simple, but in reality there is no limit.

Looping

It’s easy to make use of programming when using purely R code to
generate PowerPoints. For instance, we could stick our code into a for
loop, and add a slide for each Penguin species

# Read in doc again
# this resets the doc object to the original file
doc = read_pptx("mytemplate.pptx")

for (penguin_species in c("Adelie", "Chinstrap", "Gentoo")) {
 doc = add_slide(doc, layout = "Title Slide", master = "Office Theme")
 # Add the title using the iterator value
 doc = ph_with(
 doc,
 value = penguin_species,
 location = ph_location_label("title")
 )
 # Create the plot using the iterator value
 penguin_plot = penguins |>
 filter(species == penguin_species) |>
 ggplot(aes(x = bill_length_mm, y = flipper_length_mm)) +
 geom_point() +
 theme_linedraw()
 theme(
 plot.background = element_rect(fill = "transparent", colour = NA),
 panel.background = element_rect(fill = "#F1EADE", colour = NA)) +
 labs(
 x = "Bill Length (mm)",
 y = "Flipper Length (mm)")
 # Add the plot
 doc = ph_with(
 doc,
 value = adelie_plot,
 location = ph_location_label("plot")
 )
}
# Output to a file
print(doc, "penguins_loop.pptx")

Conclusion

There are a few drawbacks to this method:

It is quite annoying to insert large amounts of text using just an R
script
Content added to the “Slide Master” slide cannot be moved or edited on
the output file
The web version of powerpoint doesn’t have the Slide Master
functionality features

However, I think the pros outweigh the cons:

For updates and revisions to this article, see the original post