Why your custom post type URLs 404 (and how to never re-save permalinks again)

说明与用途

该方案仅在路由更改时自动刷新 WordPress 重写规则，消除了手动重新保存永久链接的需求，并防止了性能问题。

问题

Custom post type URLs return 404 until permalinks are re‑saved, causing a recurring manual ritual.

结果

The recipe automates rewrite rule flushing only when routes change, eliminating the need to manually re‑save permalinks and preventing performance regressions.

工作流

• Register the custom post type during init.
• Hook a function to wp_loaded that checks a fingerprint of $wp_rewrite.
• If the fingerprint differs from the stored option, perform a soft flush_rewrite_rules(false) and update the fingerprint option.
• Optionally cap rebuilds to 5 per 10 minutes to avoid excessive flushing on admin‑ajax requests.
• Ensure the hook runs at priority PHP_INT_MAX so all routes are registered.
• Use a soft flush to avoid rewriting .htaccess.
• Maintain a counter of rebuilds in an option to enforce the cap.

证据

WordPress doesn’t create any URL rules yet. It records a permastruct (/recipes/%recipe%) in the global $wp_rewrite object.

来源

The function’s documentation warns that flushing is expensive and belongs in activation hooks, not on every page load.

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A soft flush rebuilds the rules in the database and leaves .htaccess alone.

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I wrote a test that reproduced it first: alternate 10 front‑end requests with 10 admin‑ajax.php requests and count the rebuilds. The result was 20 rebuilds in 20 requests.

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