Using web-hosted boards

The pins package supports back-and-forth collaboration for publishing and consuming using, for example, board_s3(). The goal of this vignette is to show how to publish a board of pins to a website, bringing your pins to a wider audience. How does this work?

Publishing

The steps for publishing a board that can be read by consumers using board_url() are:

create a board,
write pins to the board,
write a manifest file using write_board_manifest(), and
publish your website.

The first and last steps will be specific to how you deploy your board on the web; we discuss options in the Publishing platforms section. Regardless of platform, you’ll write the pins and the manifest the same way.

For this first demonstration, we’ll start by creating a board, and finish by showing how the board works after being served.

library(pins)
board <- board_temp(versioned = TRUE)

We’re using a temporary board for this demonstration, but in practice, you might use board_folder() in a project folder or GitHub repo, or perhaps board_s3().

Let’s make the mtcars dataset available as a JSON file:

board %>% pin_write(mtcars, type = "json")
#> Using `name = 'mtcars'`
#> Creating new version '20231109T155351Z-c4fcd'
#> Writing to pin 'mtcars'

Let’s make a new version of this data by adding a column: lper100km, consumption in liters per 100 km. This could make our data friendlier to folks outside the United States.

mtcars_metric <- mtcars
mtcars_metric$lper100km <- 235.215 / mtcars$mpg

board %>% pin_write(mtcars_metric, name = "mtcars", type = "json")
#> Creating new version '20231109T155354Z-19d36'
#> Writing to pin 'mtcars'

Let’s check our board to ensure we have one pin named "mtcars", with two versions:

board %>% pin_list()
#> [1] "mtcars"

board %>% pin_versions("mtcars")
#> # A tibble: 2 × 3
#>   version                created             hash 
#>   <chr>                  <dttm>              <chr>
#> 1 20231109T155351Z-c4fcd 2023-11-09 08:53:51 c4fcd
#> 2 20231109T155354Z-19d36 2023-11-09 08:53:54 19d36

Because a board_url() is consumed over the web, it doesn’t have access to a file system the way, for example, a board_folder() has; we can work around this by creating a manifest file. When a board_url() is set up by a consumer for reading, the pins package uses this file to discover the pins and their versions. The manifest file is the key to board_url()’s ability to discover pins as if it were a file-system-based board.

After writing pins but before publishing, call write_board_manifest():

board %>% write_board_manifest()
#> Manifest file written to root folder of board, as `_pins.yaml`

The maintenance of this manifest file is not automated; it is your responsibility as the board publisher to keep the manifest up to date.

Let’s confirm that there is a file called _pins.yaml:

withr::with_dir(board$path, fs::dir_ls())
#> _pins.yaml mtcars

We can inspect its contents to see each pin in the board, and each version of each pin:

mtcars:
- mtcars/20231109T155351Z-c4fcd/
- mtcars/20231109T155354Z-19d36/

At this point, we would publish the folder containing the board as a part of a web site. Let’s pretend that we have served the folder from our fake website, https://not.real.website.co/pins/.

Consuming

With an up-to-date manifest file, a board_url() can behave as a read-only version of a board_folder(). Let’s create a board_url() using our fake URL:

web_board <- board_url("https://not.real.website.co/pins/")

The board_url() function reads the manifest file to discover the pins and versions:

web_board %>% pin_list()
#> [1] "mtcars"

versions <- web_board %>% pin_versions("mtcars")
versions
#> # A tibble: 2 × 3
#>   version                created             hash 
#>   <chr>                  <dttm>              <chr>
#> 1 20231109T155351Z-c4fcd 2023-11-09 08:53:51 c4fcd
#> 2 20231109T155354Z-19d36 2023-11-09 08:53:54 19d36

We can read the most-recent version of the "mtcars" pin:

web_board %>% pin_read("mtcars") %>% head()
#>    mpg cyl disp  hp drat    wt  qsec vs am gear carb lper100km
#> 1 21.0   6  160 110 3.90 2.620 16.46  0  1    4    4   11.2007
#> 2 21.0   6  160 110 3.90 2.875 17.02  0  1    4    4   11.2007
#> 3 22.8   4  108  93 3.85 2.320 18.61  1  1    4    1   10.3164
#> 4 21.4   6  258 110 3.08 3.215 19.44  1  0    3    1   10.9914
#> 5 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2   12.5783
#> 6 18.1   6  225 105 2.76 3.460 20.22  1  0    3    1   12.9953

We can also read the first version:

web_board %>% pin_read("mtcars", version = versions$version[[1]]) %>% head()
#>    mpg cyl disp  hp drat    wt  qsec vs am gear carb
#> 1 21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
#> 2 21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
#> 3 22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
#> 4 21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
#> 5 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
#> 6 18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

Publishing platforms

The goal of this section is to illustrate ways to publish a board as a part of a website.

pkgdown

Pins offers another way for package developers to share data associated with an R package. Publishing a package dataset as a pin can extend your data’s “audience” to those who have not installed the package.

Using pkgdown, any files you save in the directory pkgdown/assets/ will be copied to the website’s root directory when pkgdown::build_site() is run.

The R Packages book suggests using a folder called data-raw for working with datasets; this can be adapted to use pins. You would start with usethis::use_data_raw(). In a file in your /data-raw directory, wrangle and clean your datasets in the same way as if you were going to use usethis::use_data(). To offer such datasets on a web-based board instead of as a built-in package dataset, in your /data-raw file you would:

Create a board: board_folder(here::here("pkgdown/assets/pins-board")) (you might use a different name than "pins-board").
Write your datasets to the board using pin_write().
At the end, call write_board_manifest().

Now when you build your pkgdown site and serve it (perhaps via GitHub Pages at a URL like https://user-name.github.io/repo-name/), your datasets are available as pins.

The R Packages book offers this observation on CRAN and package data:

Generally, package data should be smaller than a megabyte - if it’s larger you’ll need to argue for an exemption.

Publishing a board on your pkgdown site provides a way to offer datasets too large for CRAN or extended versions of your data. A consumer can read your pins by setting up a board like:

board <- board_url("https://user-name.github.io/repo-name/pins-board/")

S3

S3 buckets can be made available to different users using permissions; buckets can even be made publicly accessible. Publishing data as a pin in an S3 bucket can allow your collaborators to read without dealing with the authentication required by board_s3().

To offer datasets as a pin on S3 via board_url() you would:

Create a board: board_s3("your-existing-bucket") (set the bucket’s permissions to give appropriate people access).
Write your datasets to the board using pin_write().
At the end, call write_board_manifest().

S3 buckets typically have a URL like https://your-existing-bucket.s3.us-west-2.amazonaws.com/. For a person who has access to your bucket, they can read your pins by setting up a board like:

board <- board_url("https://your-existing-bucket.s3.us-west-2.amazonaws.com/")