Message • shiny.element

A set of modal boxes simulating system message box, mainly for alerting information, confirm operations and prompting messages.

Tip

By design MessageBox provides simulations of system’s alert, confirm and prompt，so it’s content should be simple. For more complicated contents, please use Dialog.

Alert

Alert interrupts user operation until the user confirms.

Open an alert by calling the ElMessageBox.alert method. It simulates the system’s alert, and cannot be closed by pressing ESC or clicking outside the box. In this example, two parameters message and title are received. It is worth mentioning that when the box is closed, it returns a Promise object for further processing. If you are not sure if your target browsers support Promise, you should import a third party polyfill or use callbacks instead like this example.

The answer is input$<id>: "confirm", "cancel" or "close".

ui <- el_page(el_button("open", "Click to open the Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "answer",
      "This is a message",
      title = "Title",
      box_type = "alert",
      confirm_button_text = "OK"
    )
  )
}
shinyApp(ui, server)

Confirm

Confirm is used to ask users’ confirmation.

Call ElMessageBox.confirm method to open a confirm, and it simulates the system’s confirm. We can also highly customize Message Box by passing a third attribute options which is a literal object. The attribute type indicates the message type, and it’s value can be primary, success, error, info and warning. Note that the second attribute title must be a string, and if it is an object, it will be handled as the attribute options. Here we use Promise to handle further processing. primary has been added in 2.9.11.

ui <- el_page(el_button("open", "Click to open the Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "answer",
      "proxy will permanently delete the file. Continue?",
      title = "Warning",
      type = "warning",
      confirm_button_text = "OK",
      cancel_button_text = "Cancel"
    )
  )
  observeEvent(
    input$answer,
    el_message(session, paste("Answer:", input$answer))
  )
}
shinyApp(ui, server)

Prompt

Prompt is used when user input is required.

Call ElMessageBox.prompt method to open a prompt, and it simulates the system’s prompt. You can use inputPattern parameter to specify your own RegExp pattern. Use inputValidator to specify validation method, and it should return Boolean or String. Returning false or String means the validation has failed, and the string returned will be used as the inputErrorMessage. In addition, you can customize the placeholder of the input box with inputPlaceholder parameter.

ui <- el_page(el_button("open", "Click to open Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "email",
      "Please input your e-mail",
      title = "Tip",
      box_type = "prompt",
      confirm_button_text = "OK",
      cancel_button_text = "Cancel",
      input_pattern = "[\\w!#$%&'*+/=?^_`{|}~-]+(?:\\.[\\w!#$%&'*+/=?^_`{|}~-]+)*@(?:[\\w](?:[\\w-]*[\\w])?\\.)+[\\w](?:[\\w-]*[\\w])?",
      input_error_message = "Invalid Email"
    )
  )
}
shinyApp(ui, server)

Use VNode

message can be VNode.

A message can be a VNode, built in the browser: give it as JS() code calling Vue.h(). One with props that change – the switch – is a function returning the VNode, as upstream says.

ui <- el_page(
  el_button("open", "Common VNode", plain = TRUE),
  el_button("open1", "Dynamic props", plain = TRUE)
)
server <- function(input, output, session) {
  observeEvent(input$open, {
    el_message_box(
      session,
      "vn",
      JS(
        "Vue.h('p', null, [
          Vue.h('span', null, 'Message can be '),
          Vue.h('i', { style: 'color: teal' }, 'VNode')
        ])"
      ),
      title = "Message",
      box_type = "alert"
    )
  })
  observeEvent(input$open1, {
    el_message_box(
      session,
      "vn1",
      JS(
        "(function() {
          var checked = Vue.ref(false);
          return function() {
            return Vue.h(ElementPlus.ElSwitch, {
              modelValue: checked.value,
              'onUpdate:modelValue': function(v) { checked.value = v; }
            });
          };
        })()"
      ),
      title = "Message",
      box_type = "alert"
    )
  })
}
shinyApp(ui, server)

Use VNode With Action Handlers

You can receive { confirm, cancel, close } as parameters in message, which allows custom content to trigger the same MessageBox actions programmatically and automatically close the instance.

A function message is handed the box’s own actions, confirm, cancel and close, for buttons of its own. The answer reaches the server as input$handled, as for any message box.

ui <- el_page(el_button("open", "Click to open Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(input$open, {
    el_message_box(
      session,
      "handled",
      JS(
        "function({ confirm, cancel, close }) {
          var button = function(props, text) {
            return Vue.h(ElementPlus.ElButton, props, function() { return text; });
          };
          return Vue.h('div', [
            Vue.h('p', { style: 'margin-bottom: 8px' },
              'Custom buttons with MessageBox action handlers'),
            button({ type: 'primary', onClick: function() { confirm(); } }, 'Resolve'),
            button({ type: 'danger', onClick: function() { cancel(); } }, 'Reject'),
            button({ onClick: function() { close(); } }, 'Close')
          ]);
        }"
      ),
      title = "Message",
      show_confirm_button = FALSE,
      show_cancel_button = FALSE,
      distinguish_cancel_and_close = TRUE
    )
  })
  observeEvent(
    input$handled,
    el_message(session, paste("Answer:", input$handled))
  )
}
shinyApp(ui, server)

The use-vnode-with-action-handlers example, running

Customization

Can be customized to show various content.

The three methods mentioned above are repackagings of the ElMessageBox method. This example calls ElMessageBox method directly using the showCancelButton attribute, which is used to indicate if a cancel button is displayed. Besides we can use cancelButtonClass to add a custom style and cancelButtonText to customize the button text (the confirm button also has these fields, and a complete list of fields can be found at the end of this documentation). This example also uses the beforeClose attribute. It is a method and will be triggered when the MessageBox instance will be closed, and its execution will stop the instance from closing. It has three parameters: action, instance and done. Using it enables you to manipulate the instance before it closes, e.g. activating loading for confirm button; you can invoke the done method to close the MessageBox instance (if done is not called inside beforeClose, the instance will not be closed).

ui <- el_page(el_button("open", "Click to open Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "answer",
      "This is a message",
      title = "Title",
      show_cancel_button = TRUE,
      confirm_button_text = "OK",
      cancel_button_text = "Cancel",
      confirm_button_type = "danger",
      button_size = "small"
    )
  )
}
shinyApp(ui, server)

Use HTML String

message supports HTML string.

Set dangerouslyUseHTMLString to true and message will be treated as an HTML string.

ui <- el_page(el_button("open", "Click to open Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "answer",
      "<strong>proxy is <i>HTML</i> string</strong>",
      title = "HTML String",
      box_type = "alert",
      dangerously_use_html_string = TRUE
    )
  )
}
shinyApp(ui, server)

Warning

Although message property supports HTML strings, dynamically rendering arbitrary HTML on your website can be very dangerous because it can easily lead to XSS attacks. So when dangerouslyUseHTMLString is on, please make sure the content of message is trusted, and never assign message to user-provided content.

Distinguishing cancel and close

In some cases, clicking the cancel button and close button may have different meanings.

By default, the parameters of Promise’s reject callback and callback are ‘cancel’ when the user cancels (clicking the cancel button) and closes (clicking the close button or mask layer, pressing the ESC key) the MessageBox. If distinguishCancelAndClose is set to true, the parameters of the above two operations are ‘cancel’ and ‘close’ respectively.

ui <- el_page(el_button("open", "Click to open Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "answer",
      "You have unsaved changes, save and proceed?",
      title = "Confirm",
      distinguish_cancel_and_close = TRUE,
      confirm_button_text = "Save",
      cancel_button_text = "Discard Changes"
    )
  )
}
shinyApp(ui, server)

The distinguishable-close-cancel example, running

Centered content

Content of MessageBox can be centered.

Setting center to true will center the content.

ui <- el_page(el_button("open", "Click to open Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "answer",
      "proxy will permanently delete the file. Continue?",
      title = "Warning",
      type = "warning",
      center = TRUE,
      confirm_button_text = "OK",
      cancel_button_text = "Cancel"
    )
  )
}
shinyApp(ui, server)

Customized Icon

The icon can be customized to any Vue component or render function (JSX).

ui <- el_page(el_button("open", "Click to open Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "answer",
      "Are you sure to delete this?",
      title = "Warning",
      type = "warning",
      icon = "Delete",
      confirm_button_text = "OK",
      cancel_button_text = "Cancel"
    )
  )
}
shinyApp(ui, server)

Draggable

MessageBox can be draggable.

Setting draggable to true allows user to drag MessageBox. Set overflow 2.5.4 to true can drag overflow the viewport.

ui <- el_page(el_button("open", "Click to open Message Box", plain = TRUE))
server <- function(input, output, session) {
  observeEvent(
    input$open,
    el_message_box(
      session,
      "answer",
      "proxy will permanently delete the file. Continue?",
      title = "Warning",
      type = "warning",
      draggable = TRUE,
      confirm_button_text = "OK",
      cancel_button_text = "Cancel"
    )
  )
}
shinyApp(ui, server)

Global method

If Element Plus is fully imported, it will add the following global methods for app.config.globalProperties: $msgbox, $alert, $confirm and $prompt. So in a Vue instance you can call MessageBox like what we did in this page. The parameters are:

$msgbox(options)
$alert(message, title, options) or $alert(message, options)
$confirm(message, title, options) or $confirm(message, options)
$prompt(message, title, options) or $prompt(message, options)

App context inheritance > 2.0.4

Now message box accepts a context as second (fourth if you are using message box variants) parameter of the message constructor which allows you to inject current app’s context to message which allows you to inherit all the properties of the app.

Local import

If you prefer importing MessageBox on demand:

The corresponding methods are: ElMessageBox, ElMessageBox.alert, ElMessageBox.confirm and ElMessageBox.prompt. The parameters are the same as above.

API

Element Plus’s tables, and beside each entry where it is in R.

Options

Element	In R	Description	Type	Accepted	Default
`autofocus`	`autofocus`	auto focus when open MessageBox	¹		true
`title`	`title`	title of the MessageBox	²		’’
`message`	`message`	content of the MessageBox	³ / ⁴ / ⁵`() => VNode` ^(2.2.17) / ⁶`({ confirm, cancel, close }) => VNode` ^(2.14.0)		—
`dangerouslyUseHTMLString`	`dangerously_use_html_string`	whether `message` is treated as HTML string	⁷		false
`type`	`type`	message type, used for icon display	⁸`'primary' (2.9.11) \\\| 'success' \\\| 'info' \\\| 'warning' \\\| 'error'`		’’
`icon`	`icon`	custom icon component, overrides `type`	⁹ / ¹⁰		’’
`closeIcon`	`close_icon`	custom close icon component, default is Close	¹¹ / ¹²		’’
`customClass`	`custom_class`	custom class name for MessageBox	¹³		’’
`customStyle`	`custom_style`	custom inline style for MessageBox	¹⁴		{}
`modal`	`modal`	whether a mask is displayed	¹⁵		true
`modalClass`	`modal_class`	custom class names for mask	string		—
`callback`	``input$<id>`, the answer`\| MessageBox closing callback if you don't prefer Promise \| ^[Function]`(value: string, action: Action) => any \	(action: Action) => any`\| \| null \| \|`showClose`\|`show_close`\| whether to show close icon of MessageBox \| ^[boolean] \| \| true \| \|`beforeClose`\|`before_close`\| callback before MessageBox closes, and it will prevent MessageBox from closing \| ^[Function]`(action: Action, instance: MessageBoxState, done: () => void) => void`\| \| null \| \|`distinguishCancelAndClose`\|`distinguish_cancel_and_close`\| whether to distinguish canceling and closing the MessageBox \| ^[boolean] \| \| false \| \|`lockScroll`\|`lock_scroll`\| whether to lock body scroll when MessageBox prompts \| ^[boolean] \| \| true \| \|`showCancelButton`\|`show_cancel_button`\| whether to show a cancel button \| ^[boolean] \| \| false (true when called with confirm and prompt) \| \|`showConfirmButton`\|`show_confirm_button`\| whether to show a confirm button \| ^[boolean] \| \| true \| \|`cancelButtonText`\|`cancel_button_text`\| text content of cancel button \| ^[string] \| \| Cancel \| \|`confirmButtonText`\|`confirm_button_text`\| text content of confirm button \| ^[string] \| \| OK \| \|`cancelButtonType`\|`cancel_button_type`\| type of cancel button \| ^[enum]`‘primary’ \	‘success’ \	‘warning’ \	‘danger’ \