HTMLDialogElement.showModal()

The showModal() method of the HTMLDialogElement interface displays the dialog as a modal, over the top of any other dialogs that might be present. It displays into the top layer, along with a ::backdrop pseudo-element. Interaction outside the dialog is blocked and the content outside it is rendered inert.

Syntax

showModal()

Parameters

None.

Return value

None (undefined).

Exceptions

InvalidStateError DOMException

Thrown if the dialog is already open (i.e. if the open attribute is already set on the <dialog> element).

Examples

The following example shows a simple button that, when clicked, opens a <dialog> containing a form via the showModal() method. From there you can click the Cancel button to close the dialog (via the HTMLDialogElement.close() method), or submit the form via the submit button.

<!-- Simple pop-up dialog box, containing a form -->
<dialog id="favDialog">
  <form method="dialog">
    <p>
      <label for="favAnimal">Favorite animal:</label>
      <select id="favAnimal" name="favAnimal">
        <option></option>
        <option>Brine shrimp</option>
        <option>Red panda</option>
        <option>Spider monkey</option>
      </select>
    </p>
    <div>
      <button id="cancel" type="reset">Cancel</button>
      <button type="submit">Confirm</button>
    </div>
  </form>
</dialog>

<div>
  <button id="updateDetails">Update details</button>
</div>

<script>
  (() => {
    const updateButton = document.getElementById("updateDetails");
    const cancelButton = document.getElementById("cancel");
    const dialog = document.getElementById("favDialog");
    dialog.returnValue = "favAnimal";

    function openCheck(dialog) {
      if (dialog.open) {
        console.log("Dialog open");
      } else {
        console.log("Dialog closed");
      }
    }

    // Update button opens a modal dialog
    updateButton.addEventListener("click", () => {
      dialog.showModal();
      openCheck(dialog);
    });

    // Form cancel button closes the dialog box
    cancelButton.addEventListener("click", () => {
      dialog.close("animalNotChosen");
      openCheck(dialog);
    });
  })();
</script>

Note: You can find this example on GitHub as htmldialogelement-basic (see it live also).

Specifications

Specification
HTML Standard
# dom-dialog-showmodal-dev

Browser compatibility

BCD tables only load in the browser

See also

  • The HTML element implementing this interface: <dialog>.