wp_is_local_html_output( string $html ): bool|null
- Since
- 5.7.0
- Source
wp-includes/https-detection.php:173
Description
This function attempts to check for various common WordPress patterns whether they are included in the HTML string.
Since any of these actions may be disabled through third-party code, this function may also return null to indicate that it was not possible to determine ownership.
Compatibility
- WordPress
- since 5.7.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$htmlstring- Full HTML output string, e.g. from a HTTP response.
Return value
bool|null- True/false for whether HTML was generated by this site, null if unable to determine.
Performance profile
How much work a call to wp_is_local_html_output() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Moderate
- Scaling
- Constant
- Instructions
- 12–20
- Plugin surface
- None
- Called by
- 1
Reads stored settings via get_option(), cached per request but not free on a cold cache.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 32.
Nothing here hands control to plugin code.
1 place in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()one call below wp_is_local_html_output() - optionoption read or write
get_option()one call below wp_is_local_html_output()
Further down the call graph this can also reach cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 3 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_is_local_html_output() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!has_action() | 12 | has_action(), has_action() |
has_action() | 17 | has_action(), site_url(), esc_url() |
| always | 20 | has_action(), has_action(), get_rest_url(), esc_url() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 32 | 12–20 | 2 | |
| 8.5 | 32 | 12–20 | 2 | |
| 8.4 | 32 | 12–20 | 2 | 14 fewer instructions than PHP 8.3 |
| 8.3 | 46 | 12–27 | 2 | |
| 8.2 | 46 | 12–27 | 2 | |
| 8.1 | 46 | 12–27 | 2 | |
| 7.4 | 46 | 12–27 | 2 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 5
- has_action()Checks if any action has been registered for a hook.
- esc_url()Checks and cleans a URL.
- site_url()Retrieves the URL for the current site where WordPress application files (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.
- str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
- get_rest_url()Retrieves the URL to a REST endpoint on a site.
Used by · 1
- wp_get_https_detection_errors()Runs a remote HTTPS request to detect whether HTTPS supported, and stores potential errors.
Source code
function wp_is_local_html_output( $html ) { // 1. Check if HTML includes the site's Really Simple Discovery link. if ( has_action( 'wp_head', 'rsd_link' ) ) { $pattern = preg_replace( '#^https?:(?=//)#', '', esc_url( site_url( 'xmlrpc.php?rsd', 'rpc' ) ) ); // See rsd_link(). return str_contains( $html, $pattern ); } // 2. Check if HTML includes the site's REST API link. if ( has_action( 'wp_head', 'rest_output_link_wp_head' ) ) { // Try both HTTPS and HTTP since the URL depends on context. $pattern = preg_replace( '#^https?:(?=//)#', '', esc_url( get_rest_url() ) ); // See rest_output_link_wp_head(). return str_contains( $html, $pattern ); } // Otherwise the result cannot be determined. return null;}Changelog
Introduced in 5.7.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 7.0.4 tag, from
src/wp-includes/https-detection.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.