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globalThis.assertSpeculationRulesIsSupported = () => {
assert_implements(
'supports' in HTMLScriptElement,
'HTMLScriptElement.supports must be supported');
assert_implements(
HTMLScriptElement.supports('speculationrules'),
'<script type="speculationrules"> must be supported');
};
// If you want access to these, be sure to include
// /html/browsers/browsing-the-web/remote-context-helper/resources/remote-context-helper.js.
// So as to avoid requiring everyone to do that, we only conditionally define this infrastructure.
if (globalThis.RemoteContextHelper) {
class PreloadingRemoteContextWrapper extends RemoteContextHelper.RemoteContextWrapper {
/**
* Starts preloading a page with this `PreloadingRemoteContextWrapper` as the
* referrer, using `<script type="speculationrules">`.
*
* @param {"prefetch"|"prerender"} preloadType - The preload type to use.
* @param {object} [extrasInSpeculationRule] - Additional properties to add
* to the speculation rule JSON.
* @param {RemoteContextConfig|object} [extraConfig] - Additional remote
* context configuration for the preloaded context.
* @returns {Promise<PreloadingRemoteContextWrapper>}
*/
addPreload(preloadType, { extrasInSpeculationRule = {}, ...extraConfig } = {}) {
const referrerRemoteContext = this;
return this.helper.createContext({
executorCreator(url) {
return referrerRemoteContext.executeScript((url, preloadType, extrasInSpeculationRule) => {
const script = document.createElement("script");
script.type = "speculationrules";
script.textContent = JSON.stringify({
[preloadType]: [
{
source: "list",
urls: [url],
...extrasInSpeculationRule
}
]
});
document.head.append(script);
}, [url, preloadType, extrasInSpeculationRule]);
},
extraConfig
});
}
}
globalThis.PreloadingRemoteContextHelper = class extends RemoteContextHelper {
static RemoteContextWrapper = PreloadingRemoteContextWrapper;
};
}