# Draw a tree of your package files and functions

    library(fusen)

# Get a tree of the package structure to help developers

`get_package_structure()` is a function that helps developers understand the package structure. It reads the `dev/config_fusen.yaml` file, adds the list of resulting functions and extra description of files.

You can know:

- The description of the flat file as issued from its Title when exists
- If the flat file is still active
- The list of R files issued from the flat file
- The list of functions inside these R files
- The list of files of tests issued from the flat file
- There is a possibility to list all functions that are called in the test files
- The vignette issued from the flat file

With `draw_package_structure()`, you can draw a tree of the package structure in the console.
This also works for any R package, not only for `fusen` built packages.

    #' \dontrun{
    #' # This only works inside a 'fusen' built package
    #' pkg_structure <- get_package_structure()
    #' draw_package_structure(pkg_structure)
    #' }
    #'
    #' # Example with a dummy package
    dummypackage <- tempfile("drawpkg.structure")
    dir.create(dummypackage)

    # {fusen} steps
    fill_description(pkg = dummypackage, fields = list(Title = "Dummy Package"))
    dev_file <- suppressMessages(
      add_flat_template(pkg = dummypackage, overwrite = TRUE, open = FALSE)
    )
    flat_file <- dev_file[grepl("flat_", dev_file)]

    usethis::with_project(dummypackage, {
      # Add an extra R file with internal function
      # to list in "keep"
      dir.create("R")
      cat("extra_fun <- function() {1}\n", file = "R/my_extra_fun.R")

      # Works with classical package
      pkg_structure <- get_package_structure()
      draw_package_structure(pkg_structure)
    })
    #> ✔ Setting active project to
    #>   "C:/Users/PC/AppData/Local/Temp/RtmpaCgLlT/drawpkg.structurea8082e5e5da4".
    #> ── No NAMESPACE file found there:  C:/Users/PC/AppData/Local/Temp/RtmpaCgLlT/dra
    #> ── keep ────────────────────────────────────────────────────────────────────────
    #>
    #> - keep
    #>   - path
    #>       + keep
    #>   - state
    #>       + 🍏 active
    #>   - R
    #>     - R/my_extra_fun.R
    #>       + 🙈 extra_fun
    #>   - tests
    #>   - vignettes
    #> ✔ Setting active project to "<no active project>".

    usethis::with_project(dummypackage, {
      # Works with 'fusen' package
      suppressMessages(
        inflate(
          pkg = dummypackage,
          flat_file = flat_file,
          vignette_name = "Get started",
          check = FALSE,
          open_vignette = FALSE
        )
      )

      pkg_structure <- get_package_structure()
      draw_package_structure(pkg_structure)
    })
    #> ✔ Setting active project to
    #>   "C:/Users/PC/AppData/Local/Temp/RtmpaCgLlT/drawpkg.structurea8082e5e5da4".
    #> ── config file for dev/flat_full.Rmd ───────────────────────────────────────────
    #> ── Reading NAMESPACE file ──────────────────────────────────────────────────────
    #> ── flat_full.Rmd ───────────────────────────────────────────────────────────────
    #> ── keep ────────────────────────────────────────────────────────────────────────
    #>
    #> - flat_full.Rmd
    #>   - flat_title
    #>       + flat_full.Rmd for working package
    #>   - path
    #>       + dev/flat_full.Rmd
    #>   - state
    #>       + 🍏 active
    #>   - R
    #>     - R/my_median.R
    #>       + 👀 my_median
    #>     - R/my_other_median.R
    #>       + 👀 my_other_median
    #>       + 🙈 sub_median
    #>   - tests
    #>       + tests/testthat/test-my_median.R
    #>       + tests/testthat/test-my_other_median.R
    #>   - vignettes
    #>       + vignettes/get-started.Rmd
    #> - keep
    #>   - path
    #>       + keep
    #>   - state
    #>       + 🍏 active
    #>   - R
    #>     - R/my_extra_fun.R
    #>       + 🙈 extra_fun
    #>   - tests
    #>   - vignettes
    #> ✔ Setting active project to "<no active project>".

# Get the list of functions from a R file

    file_path <- tempfile(fileext = ".R")
    cat(
      "my_fun <- function() {1}",
      "my_fun2 <- function() {2}",
      sep = "\n",
      file = file_path
    )
    get_all_created_funs(file_path)
    #> [1] "my_fun"  "my_fun2"