Generating placeholder slides for your presentation

Yolanda Zhou ([yolandazzz13])

2026-09-09

Overview

This vignette shows how to add placeholder slides, including title slides and section headers, to a PowerPoint presentation using autoslider.core.

The main function for this is append_all_slides, which takes in a structured page_list as input to define the slides you want to add. This approach is ideal for quickly building a standardized presentation from scratch.

Generating a Deck with append_all_slides

The append_all_slides function automates adding multiple slides by reading a page_list you provide. Each item in this list defines a single slide’s properties.

Each slide definition in the page_list must be a list containing:

type: The kind of slide to add (“title” or “section”).

to_page: The page number where the slide should be inserted.

Content parameters:

Fortype = "title", you need to provide a study_id.

For type = "section", you need to provide a section_title.

Example: Generating placeholder slides

Here’s a complete example. We’ll start with an empty presentation, define a page_list for our slides, and then call append_all_slides to generate the final deck and save it to a file.

library(officer)
library(tools)

# 1. Define a initial presentation file
input <- "My_Presentation.pptx"
read_pptx() %>% print(target = input)

expected_output_file <- file.path(
  dirname(input),
  paste0(file_path_sans_ext(basename(input)), "_final.pptx")
)

# 2. Define the presentation structure with a page_list
my_page_list <- list(
  list(type = "title", to_page = 1, study_id = "Project No.1"),
  list(type = "section", to_page = 2, section_title = "Introduction"),
  list(type = "section", to_page = 3, section_title = "Methodology")
)

# 3. Call append_all_slides to generate the deck
# Set save_file = TRUE to write the result to a new file.
# If you have an existing pptx object to modify on, pass it into `doc_original`.
doc_result <- append_all_slides(
  doc_o = temp_pptx,
  page_list = my_page_list,
  doc_original = NULL,
  save_file = TRUE
)

# 4. Verify the output
cat(paste("Number of slides created:", length(doc_result), "\n"))
cat(paste("Output file exists:", file.exists(expected_output_file)))

This script produces a new PowerPoint file named My_Presentation_final.pptx, containing the three slides defined in my_page_list.

Controlling slide text with metadata tokens

Rather than hard-coding study-level details (study number, data cut-off date, …) into every slide, you can write {token} placeholders in the slide text and let autoslider.core fill them in from a single, user-controlled metadata list. This keeps values such as the study number in one place instead of scattered across the deck.

A metadata list is a plain named list. You can define it inline, or keep it in a small YAML file that you own and load with yaml::read_yaml():

metadata <- list(study = "BP12345", cutoff = "2026-01-15")

Pass metadata to append_all_slides() and use {token} in study_id / section_title. Each {token} is replaced with the matching value from metadata:

my_page_list <- list(
  list(type = "title", to_page = 1, study_id = "Study {study} "),
  list(type = "section", to_page = 2, section_title = "Efficacy - Study {study}"),
  list(type = "section", to_page = 3, section_title = "Data cut-off {cutoff}")
)

doc_result <- append_all_slides(
  doc_o = input,
  page_list = my_page_list,
  save_file = TRUE,
  metadata = metadata
)

Here the section header reads “Efficacy - Study BP12345” on the generated slide. The same metadata list also drives titles and footnotes for tables, listings and graphs when passed to read_spec() (see ?read_spec), so one list controls the text across the whole deck.

A few rules worth knowing:

• Tokens use glue syntax: name is matched to the name element of metadata.
• An unknown token (e.g. a typo like {studdy}) raises an informative error rather than silently printing the literal text, so mistakes surface early.
• Text with no {token} and no metadata behaves exactly as before, so this feature is fully opt-in.

The underlying substitution is done by apply_tokens(), which you can also call directly:

library(autoslider.core)
#> Registered S3 method overwritten by 'tern':
#>   method   from 
#>   tidy.glm broom
apply_tokens("Efficacy - Study {study}", list(study = "BP12345"))
#> Efficacy - Study BP12345

Notes

• to_page parameter: The function validates that it does not exceed the maximum possible slide position (number of slides + 1). After a slide is inserted at a specific page, all subsequent page numbers shift. Plan your page_list sequence accordingly.

• The functions are designed to work with standard officer layouts. They will fail if PowerPoint does not support the specified layouts (“Title and Content”, “Section Header”) and master theme (“Office Theme”).