Fence: getNestedConfigs() method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The getNestedConfigs() method of the Fence interface returns the FencedFrameConfigs loaded into <fencedframe>s embedded inside the current <fencedframe>.

Syntax

js
getNestedConfigs()

Parameters

None.

Return value

getNestedConfigs() has two possible return values:

  • An array of 20 FencedFrameConfig objects, if the current <fencedframe>'s config was created using an API that supports nested configs (for example Protected Audience). Of these 20 configs, the first N configs are those registered through the API and the rest are padding configs that will navigate to about:blank, so that the number of configs is hidden and cannot leak any information.
  • null if the current <fencedframe>'s config was created using an API that does not support nested configs (for example Shared Storage).

Examples

js
// Run inside a <fencedframe>

// Retrieve the configs of embedded fenced frames
const configs = window.fence.getNestedConfigs();

// Set a new fenced frame's config to equal one of the retrieved configs
const frame = document.createElement("fencedframe");
frame.config = configs[0];

Specifications

Specification
Fenced Frame
# dom-fence-getnestedconfigs

Browser compatibility

BCD tables only load in the browser

See also