/tar-render-book-demo

Primary LanguageHTML

tar-render-book-demo

The goal of tar-render-book-demo is to provide a preview of creating a bookdown book using a targets pipeline.

This project was created with the template book by calling bookdown::create_bs4_book(path = "demo-book"). I added a section to the file demo-book/01-intro.Rmd to use the data target created as part of the default _targets.R file generated with targets::tar_script(). I also modified the demo-book/index.Rmd file to write the ‘packages.bib’ to demo-book/packages.bib.

After running the pipeline, any time we update or modify a file in the “demo-book” folder, the target demo_book will become outdated.

_targets.R File

library(targets)

source("R/utils-tar-render-book.R")
source("R/tar-render-book.R")

summ <- function(dataset) {
  dplyr::summarize(dataset, mean_x = mean(x))
}

# Set target-specific options such as packages.
tar_option_set(packages = "dplyr")

# End this file with a list of target objects.
list(
  tar_target(data, data.frame(x = sample.int(100), y = sample.int(100))),
  tar_target(summary, summ(data)),
  tar_render_book(
    demo_book,
    path = "demo-book",
    # Will create bs4_book and pdf_book
    output_format = c(
      "bookdown::bs4_book",
      "bookdown::pdf_book"
    )
  )
)

Run and Visualize Pipeline

targets::tar_make()
✓ skip target data
• start target demo_book
Rendering book in directory 'demo-book'
Tweaking _book/index.html
Tweaking _book/hello-bookdown.html
Tweaking _book/adding-a-targets-dependency.html
Tweaking _book/cross.html
Tweaking _book/parts.html
Tweaking _book/footnotes-and-citations.html
Tweaking _book/blocks.html
Tweaking _book/sharing-your-book.html
Tweaking _book/references.html
Tweaking _book/404.html
• built target demo_book
✓ skip target summary
• end pipeline
targets::tar_visnetwork(targets_only = TRUE)

Invalidate Pipeline

We can invalidate the pipeline by modifying any of the files in the “demo-book” directory. One easy way is just to add a new line to a file.

writeLines(
  text = c(
    readLines("demo-book/01-intro.Rmd"), 
    "new line here!"
    ),
  con = "demo-book/01-intro.Rmd"
  )
targets::tar_visnetwork(targets_only = TRUE)