Board plugin

A core mechanism for extending or customizing UX aspects of the board module is a "plugin" architecture. All plugins inherit from plugin and a sub-class is assigned to each specific plugin. The "manage blocks" plugin for example has a class vector c("manage_blocks", "plugin"). Sets of plugins are handled via a wrapper class plugins. Each plugin needs a server component, in most cases accompanied by a UI component and is optionally bundled with a validator function.

Usage

new_plugin(server, ui = NULL, validator = abort_not_null, class = character())

is_plugin(x)

abort_not_null(x)

as_plugin(x)

board_plugins(x, ...)

plugins(...)

is_plugins(x)

as_plugins(x)

validate_plugins(x)

Arguments

server, ui

Server/UI for the plugin module

validator

Validator function that validates server return values

class

Plugin subclass

x

Plugin object

...

Plugin objects

Value

Constructors new_plugin()/plugins() return plugin and plugins objects, respectively, as do as_plugin()/as_plugins() and validators validate_plugin()/validate_plugins(), which are typically called for their side effects of throwing errors in case of validation failure. Inheritance checkers is_plugin()/is_plugins() return scalar logicals and finally, the convenience function board_plugins() returns a plugins object with all known plugins (or a selected subset thereof).

Examples

plg <- board_plugins(new_board())

is_plugins(plg)
#> [1] TRUE
names(plg)
#> [1] "preserve_board" "manage_blocks"  "manage_links"   "manage_stacks" 
#> [5] "notify_user"    "generate_code"  "edit_block"     "edit_stack"    

plg[1:3]
#> <plugins[3]>
#> preserve_board: <preserve_board<plugin>>
#> manage_blocks: <manage_blocks<plugin>>
#> manage_links: <manage_links<plugin>>

is_plugin(plg[["preserve_board"]])
#> [1] TRUE