TheselectURL() method of theWindowSharedStorage interface executes aURL Selection operation that is registered in a module added to the current origin'sSharedStorageWorklet.

Syntax

selectURL(name, urls)selectURL(name, urls, options)

Parameters

name

A string representing the registered operation's name within the shared storage worklet module. It must match the name given to the operation when it is registered withSharedStorageWorkletGlobalScope.register().

urls

An array of objects representing the URLs to be chosen between by the URL Selection operation. Each object contains two properties:

url

A string representing the URL.

reportingMetadataOptional

An object containing properties where names are event types and values are URLs pointing to reporting destinations, for example"click" : "my-reports/report1.html". The URLs act as destinations for reports submitted with a destination of type"shared-storage-select-url", typically submitted via aFence.reportEvent() orFence.setReportEventDataForAutomaticBeacons() method call.

optionsOptional

An options object, which can contain the following properties:

dataOptional

An object representing any data required for executing the operation.

keepAliveOptional

A boolean value. If set totrue, theSharedStorageWorkletGlobalScope of the associated worklet is kept alive, and the operation can be run again. Therefore, you need to setkeepAlive totrue for each operation that is not intended to be the last one. The default value,false, means that theSharedStorageWorkletGlobalScope is terminated after the operation is run and cannot be run again.

resolveToConfigOptional

A boolean value. If set totrue, the fulfillment value of thePromise returned byrun() will be aFencedFrameConfig object that can be used to load content into a<fencedframe> via itsconfig attribute. The default value,false, means that the fulfillment value will be a URL that can be used to load content into an<iframe>.

Return value

APromise that fulfills with aFencedFrameConfig object or a string representing a URL, depending on the value of theresolveToConfig option.

Exceptions

TypeError

Thrown if:

• The worklet module has not yet been added withaddModule().
• urls is empty or exceeds the maximum allowed length (which is browser-specific).
• An object'surl property contains an invalid URL.
• Shared storage is disabled (for example, via a browser setting).
• The calling site does not have the Shared Storage API included in a successfulprivacy sandbox enrollment process.

Examples

Basic A/B testing

// Randomly assigns a user to a group 0 or 1function getExperimentGroup() {  return Math.round(Math.random());}async function injectContent() {  // Add the module to the shared storage worklet  await window.sharedStorage.worklet.addModule("ab-testing-worklet.js");  // Assign user to a random group (0 or 1) and store it in shared storage  window.sharedStorage.set("ab-testing-group", getExperimentGroup(), {    ignoreIfPresent: true,  });  // Run the URL selection operation  const fencedFrameConfig = await window.sharedStorage.selectURL(    "ab-testing",    [      { url: `https://your-server.example/content/default-content.html` },      { url: `https://your-server.example/content/experiment-content-a.html` },    ],    {      resolveToConfig: true,    },  );  // Render the chosen URL into a fenced frame  document.getElementById("content-slot").config = fencedFrameConfig;}injectContent();

See theShared Storage API landing page for a walkthrough of this example and links to other examples.

Specifications

Browser compatibility

See also

• Shared Storage API