Obtain the module information — module

current_module returns the information of the currently running module. It looks up the .module_id variable in the calling environment (set automatically when a module is loaded), then retrieves the corresponding row from the module table.

active_module returns a reactive value with information about the module that is currently visible in the iframe tab (or the standalone module if no iframe manager is present). Unlike current_module which is static and always returns the module whose server code is running, active_module dynamically tracks which module the user is looking at from any context.

Usage

module_info(root_path = template_root(), settings_file = "modules.yaml")

current_module(
  session = shiny::getDefaultReactiveDomain(),
  root_path = template_root()
)

active_module(
  session = shiny::getDefaultReactiveDomain(),
  root_path = template_root()
)

load_module(
  root_path = template_root(),
  request = list(QUERY_STRING = "/"),
  env = parent.frame()
)

Arguments

root_path: the root path of the website project
settings_file: the settings file containing the module information
session: shiny reactive domain; used to extract the module id from the URL query string when .module_id is not found.
request: 'HTTP' request string
env: environment to load module variables into

Value

A data frame with the following columns that contain the module information:

id: module id, folder name
order: display order in side-bar
group: group menu name if applicable, otherwise NA
label: the readable label to be displayed on the side-bar
icon: icon that will be displayed ahead of label, will be passed to as_icon
badge: badge text that will be displayed following the module label, will be passed to as_badge
url: the relative 'URL' address of the module.

current_module: a named list with id, group, label, icon, badge, and url of the current module, or NULL if no module is active.

active_module: a named list with id, group, label, icon, badge, and url of the currently active (visible) module, or NULL if no module is active.

Details

The module files are stored in modules/ folder in your project. The folder names are the module id. Within each folder, there should be one "server.R", R/, and a "module-ui.html".

The R/ folder stores R code files that generate variables, which will be available to the other two files. These variables, along with some built-ins, will be used to render "module-ui.html". The built-in functions are

ns: shiny name-space function; should be used to generate the id for inputs and outputs. This strategy avoids conflict id effectively.
.module_id: a variable of the module id
module_title: a function that returns the module label

The "server.R" has access to all the code in R/ as well. Therefore it is highly recommended that you write each 'UI' component side-by-side with their corresponding server functions and call these server functions in "server.R".

active_module works by reading the '@shidashi_active_module@' Shiny input that is set by the JavaScript front-end whenever a module tab is activated. Because it accesses session$rootScope()$input, the return value is reactive: when called inside an observe or reactive context it will re-fire whenever the user switches modules.

If the input has not been set yet (e.g. before any module is opened), the function falls back to current_module().

Examples


library(shiny)
module_info()
#>              id group          label                 icon      badge
#> 1    getstarted  <NA>    Get Started               rocket           
#> 2          card Cards          Cards               square           
#> 3       widgets Cards        Widgets         puzzle-piece           
#> 4          demo  <NA>           Demo            chart-bar           
#> 5 filestructure  <NA> File Structure          folder-open           
#> 6       page500  <NA>      Error 500 exclamation-triangle           
#> 7     module_id  <NA>   Module Label               circle New|bg-red
#>                      url
#> 1    /?module=getstarted
#> 2          /?module=card
#> 3       /?module=widgets
#> 4          /?module=demo
#> 5 /?module=filestructure
#> 6       /?module=page500
#> 7     /?module=module_id

# load master module
load_module()
#> $environment
#> <environment: 0x55e8ab78c7a0>
#> 
#> $has_module
#> [1] FALSE
#> 
#> $root_path
#> [1] "/home/runner/.local/share/R/shidashi/bslib-bare"
#> 
#> $template_path
#> [1] "/home/runner/.local/share/R/shidashi/bslib-bare/index.html"
#> 
#> $module
#> $module$id
#> NULL
#> 
#> $module$server
#> function (input, output, session, ...) 
#> {
#> }
#> <bytecode: 0x55e8abdd6d00>
#> <environment: 0x55e8abdd8e50>
#> 
#> $module$template_path
#> NULL
#> 
#> 

# load specific module
module_data <- load_module(
  request = list(QUERY_STRING = "/?module=module_id"))
env <- module_data$environment

if(interactive()){

# get module title
env$module_title()

# generate module-specific shiny id
env$ns("input1")

# generate part of the UI
env$ui()

}