Speculative Loading

常見問題集

如何將某些網址排除於預先擷取及預先轉譯之外？

Not every URL can be reasonably prerendered. Prerendering static content is typically reliable, however prerendering interactive content, such as a logout URL, can lead to issues. For this reason, certain WordPress core URLs such as /wp-login.php and /wp-admin/* are excluded from prefetching and prerendering. Additionally, any URL generated with wp_nonce_url() (or which contain the _wpnonce query var) is also ignored. You can exclude additional URL patterns by using the plsr_speculation_rules_href_exclude_paths filter.

This example would ensure that URLs like https://example.com/cart/ or https://example.com/cart/foo would be excluded from prefetching and prerendering.

<?php

add_filter(
    'plsr_speculation_rules_href_exclude_paths',
    function ( array $exclude_paths ): array {
        $exclude_paths[] = '/cart/*';
        return $exclude_paths;
    }
);

Keep in mind that sometimes it may be useful to exclude a URL from prerendering while still allowing it to be prefetched. For example, a page with client-side JavaScript to update user state should probably not be prerendered, but it would be reasonable to prefetch.

For this purpose, the plsr_speculation_rules_href_exclude_paths filter receives the current mode (either “prefetch” or “prerender”) to provide conditional exclusions.

The following example would ensure that URLs like https://example.com/products/... cannot be prerendered, while still allowing them to be prefetched.

<?php

add_filter(
    'plsr_speculation_rules_href_exclude_paths',
    function ( array $exclude_paths, string $mode ): array {
        if ( 'prerender' === $mode ) {
            $exclude_paths[] = '/products/*';
        }
        return $exclude_paths;
    },
    10,
    2
);

As mentioned above, adding the no-prerender CSS class to a link will prevent it from being prerendered (but not prefetched). Additionally, links with rel=nofollow will neither be prefetched nor prerendered because some plugins add this to non-idempotent links (e.g. add to cart); such links ideally should rather be buttons which trigger a POST request or at least they should use wp_nonce_url().

How will this impact analytics and personalization?

Prerendering can affect analytics and personalization.

For client-side JavaScript, is recommended to delay these until the page clicks and some solutions (like Google Analytics) already do this automatically for prerender. See Impact on Analytics. Additionally, cross-origin iframes are not loaded until activation which can further avoid issues here.

Speculating on hover (moderate) increases the chance the page will be loaded, over preloading without this signal, and thus reduces the risk here. Alternatively, the plugin offers to only speculate on mouse/pointer down (conservative) which further reduces the risk here and is an option for sites which are concerned about this, at the cost of having less of a lead time and so less of a performance gain.

A prerendered page is linked to the page that prerenders it, so personalisation may already be known by this point and changes (e.g. browsing other products, or logging in/out) may require a new page load, and hence a new prerender anyway, which will take these into account. But it definitely is something to be aware of and test!

使用者可以在何處提交外掛意見反應？

非常鼓勵也感謝使用者提供意見反應，尤其是這個外掛會是將來 WordPress 核心程式的功能。使用者如果有任何建議或功能要求，可以在 WordPress 效能團隊的 GitHub 存放庫提出。如果對這個外掛有需要疑難排解協助或提出問題之處，請在外掛的技術支援論壇提出。

在何處可以回報安全性程式碼錯誤？

效能團隊及 WordPress 社群對安全性程式碼錯誤一向嚴陣以待，我們非常感謝使用者披露相關發現所付出的心力，並會盡全力解決使用者提出的問題。

如需回報安全性問題，請參考 WordPress HackerOne 計畫。

如何為這個外掛做出貢獻？

非常感謝各位的各種貢獻！請參考核心程式效能團隊手冊以進一步了解參與的方式。