Display a plain-text namespace tree for a Shiny app

ns_tree() statically parses all R source files in a directory, builds a call graph of every function defined there, and prints a plain-text tree showing how functions call one another. Functions that use shiny::NS() or shiny::moduleServer() are identified as Shiny modules, but their presence is not required — ns_tree() works for any collection of R source files.

Usage

ns_tree(
  path = "R",
  app_fun = "launch",
  ui_fun = "app_ui",
  server_fun = "app_server"
)

Arguments

path: Character scalar; path to the directory containing R source files. Defaults to "R".
app_fun: Character scalar; name of the top-level app launch function used as the tree root. Defaults to "launch".
ui_fun: Character scalar; name of the UI function. Defaults to "app_ui".
server_fun: Character scalar; name of the server function. Defaults to "app_server".

Value

Invisibly returns the nested tree structure (a list). The tree is printed to the console as a side effect.

Details

The tree root is resolved with a three-tier fallback:

app_fun — a named launcher function (e.g. launch()).
ui_fun + server_fun — displayed as co-roots under (app) when no launcher is found (e.g. bare ui / server objects).
All defined functions listed flat under (app) when neither of the above is found.

Examples

# Locate the bundled demo apps
apps <- system.file("apps", package = "shooters")

# Bare ui/server — no wrapper functions, no modules
ns_tree(file.path(apps, "minimal"), ui_fun = "ui", server_fun = "server")
#> █─(app)
#> └─█─server 

# Helper functions, no Shiny modules
ns_tree(file.path(apps, "no_modules"))
#> █─launch
#> ├─█─app_ui
#> └─█─app_server
#>   ├─█─make_data
#>   └─█─render_scatter 

# One NS / moduleServer pair
ns_tree(file.path(apps, "single_module"))
#> █─launch
#> ├─█─app_ui
#> │ └─█─scatter_ui
#> └─█─app_server
#>   └─█─scatter_server 

# Modules calling other modules (multi-file)
ns_tree(file.path(apps, "nested_modules"))
#> █─launch
#> ├─█─app_ui
#> │ └─█─display_ui
#> │   ├─█─plot_ui
#> │   └─█─table_ui
#> └─█─app_server
#>   └─█─display_server
#>     ├─█─plot_server
#>     └─█─table_server