wp_internal_hosts(): string[]
- Since
- 6.2.0
- Source
wp-includes/link-template.php:4863
Description
By default the list of internal hosts is comprised of the host name of the site's home_url() (as parsed by wp_parse_url()).
This list is used when determining if a specified URL is a link to a page on the site itself or a link offsite (to an external host). This is used, for example, when determining if the "nofollow" attribute should be applied to a link.
Compatibility
- WordPress
- since 6.2.0
- 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.
Return value
string[]- An array of URL hosts.
Performance profile
How much work a call to wp_internal_hosts() 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
- Trivial
- Scaling
- Constant
- Instructions
- 4–25
- Plugin surface
- 1 hook
- Called by
- 1
Touches nothing outside its own arguments.
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 25.
Third-party callbacks on 'wp_internal_hosts' run inside this call, and their cost is not bounded by anything here.
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()called directly
Further down the call graph this can also reach option, 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 · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_internal_hosts() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!empty($internal_hosts) | 4 | none |
empty($internal_hosts) | 25 | home_url(), wp_parse_url(), array_map(), array_unique() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 25 instructions, 4–25 executed per call, 1 branch. The work does not change between versions.
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.
Hooks and filters fired · 1
One hook fires while wp_internal_hosts() runs, in this order:
- apply_filters( wp_internal_hosts )filterline 4874 (+11 into the body)
Filters the array of URL hosts which are considered internal.
Uses · 3
- apply_filters()Calls the callback functions that have been added to a filter hook.
- wp_parse_url()A wrapper for PHP's parse_url() function that handles consistency in the return values across PHP versions.
- home_url()Retrieves the URL for the current site where the front end is accessible.
Used by · 1
- wp_is_internal_link()Determines whether or not the specified URL is of a host included in the internal hosts list.
Source code
function wp_internal_hosts() { static $internal_hosts; if ( empty( $internal_hosts ) ) { /** * Filters the array of URL hosts which are considered internal. * * @since 6.2.0 * * @param string[] $internal_hosts An array of internal URL hostnames. */ $internal_hosts = apply_filters( 'wp_internal_hosts', array( wp_parse_url( home_url(), PHP_URL_HOST ), ) ); $internal_hosts = array_unique( array_map( 'strtolower', (array) $internal_hosts ) ); } return $internal_hosts;}Changelog
Introduced in 6.2.0. 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 7.1.0 tag, from
src/wp-includes/link-template.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.