Input actions

[nteetor]

!! Outdated, please see comments below !!

Description

@jcheng5, after describing the current system of showing nav panes and based on my work thus far with {yonder}, I have started implementing a new approach. I agree freezing the layout of an application during a long running process is sub-optimal. The new approach allows inputs to target elements with bootstrap plugins (navs, alerts, modals, etc.) and makes use of the data-target attributes (as you brought up) to trigger these plugin elements.

For now only navInput() has been updated. Below are some potential uses of the new targets argument.

targets is a character string

If targets is a character string the input's values are assumed as id's of plugin elements, i.e. the id of a navPane(). For now, the value "pages" is actually ignored and I am considering using TRUE instead. (The values of an input if not specified default to the choices)

navInput(
  id = "test",
  choices = c("Home", "About"),
  targets = "pages"
)

targets is a character vector

If targets is a character vector each value is considered a corresponding id target for each choice/value of the input. The targets and values are matched by index.

navInput(
  id = "test",
  choices = c("Home", "About"),
  targets = c("chicken", "dinner")
)

targets is a named vector or list

If targets is a named character vector or list the names are used to match input values to a target id. A NULL value may be used to prevent a certain input value from triggering any effect.

navInput(
  id = "test",
  choices = c("Home", "About"),
  values = c("chicken", "dinner")
  targets = c(
    chicken = "Home", 
    dinner = "About"
  )
)

targets is a list and includes multi-length items

This case allows a single input value to trigger two targets.

navInput(
  id = "test",
  choices = c("Home"),
  targets = list(
    Home = c("home_page", "info_panel")
  )
)

Demo

If you install the feat/input-targets branch you can try out the following demo.

ui <- webpage(
  navInput(
    id = "test",
    appearance = "tabs",
    choices = c("Home", "About"),
    targets = c("home_page", "about_page")  # <=
  ),
  navContent(
    id = "pages",
    navPane(
      id = "home_page",
      h1("Home")
    ),
    navPane(
      id = "about_page",
      h1("About")
    )
  )
)

server <- function(input, output) { }

shinyApp(ui, server)

[nteetor]

I have revised the API. The argument is now actions and there are explicit helper functions for possible actions.

Implicit value and id matching

Without names showTarget(X) will show a nav pane with X when a choice with value X is selected.

navInput(
  ..,
  actions = c(
    showTarget("home"),
    showTarget("about")
  )
)

Explicit value and id matching

When named Y = showTarget(X) will show a nav pane with id X when a choice with value Y is selected.

navInput(
  .., 
  actions = c(
    home = showTarget("home"),
    about = showTarget("about")
  )
)

[nteetor]

To make calling the correct plugin much easier I have switched from showTarget() to showNavTarget().

[nteetor]

I am unsure how actions will interact with updating an input. I think selecting new values must trigger any corresponding actions or an application could quickly get out of sync.