_wp_link_page( int $i ): string
- Since
- 3.1.0
- Source
wp-includes/post-template.php:1056
Compatibility
- WordPress
- since 3.1.0
- 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
$iint- Page number.
Return value
string- Link.
Performance profile
How much work a call to _wp_link_page() 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
- Heavy
- Scaling
- Constant
- Instructions
- 21–81
- Plugin surface
- None
- Called by
- 1
Reaches the database via get_post().
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 104.
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
- querycontent query
get_post()called directly - optionoption read or write
get_option()called directly - hookthird-party callbacks
apply_filters()one call below _wp_link_page() - cacheobject cache
wp_cache_get()one call below _wp_link_page() - serializeserialisation
maybe_unserialize()one call below _wp_link_page()
Further down the call graph this can also reach transient. That is the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 12 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost _wp_link_page() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
$i === 1 && !is_preview() | 21 | get_post(), get_permalink(), is_preview(), esc_url() |
$i === 1 && is_preview() | 30–36 | get_post(), get_permalink(), is_preview(), get_preview_post_link(), esc_url() |
$i !== 1 && !is_preview() | 30–33 | get_post(), get_option(), get_permalink(), add_query_arg(), is_preview(), esc_url() |
$i !== 1 && is_preview() | 39–48 | get_post(), get_option(), get_permalink(), add_query_arg(), is_preview(), get_preview_post_link(), esc_url() |
$i !== 1 && get_option() && !is_preview() | 39 | get_post(), get_option(), get_option(), get_permalink(), trailingslashit(), user_trailingslashit(), is_preview(), esc_url() |
$i !== 1 && get_option() && !is_preview() | 46–50 | get_post(), get_option(), get_option(), get_option(), get_permalink(), trailingslashit(), user_trailingslashit(), is_preview(), esc_url() |
$i !== 1 && get_option() && is_preview() | 48–54 | get_post(), get_option(), get_option(), get_permalink(), trailingslashit(), user_trailingslashit(), is_preview(), get_preview_post_link(), esc_url() |
$i === 1 && is_preview() && isset($value) | 52 | get_post(), get_permalink(), is_preview(), wp_unslash(), wp_unslash(), get_preview_post_link(), esc_url() |
$i !== 1 && get_option() && is_preview() | 55–65 | get_post(), get_option(), get_option(), get_option(), get_permalink(), trailingslashit(), user_trailingslashit(), is_preview(), get_preview_post_link(), esc_url() |
$i !== 1 && is_preview() && isset($value) | 61–64 | get_post(), get_option(), get_permalink(), add_query_arg(), is_preview(), wp_unslash(), wp_unslash(), get_preview_post_link(), esc_url() |
$i !== 1 && get_option() && is_preview() && isset($value) | 70 | get_post(), get_option(), get_option(), get_permalink(), trailingslashit(), user_trailingslashit(), is_preview(), wp_unslash(), wp_unslash(), get_preview_post_link(), esc_url() |
$i !== 1 && get_option() && is_preview() && isset($value) | 77–81 | get_post(), get_option(), get_option(), get_option(), get_permalink(), trailingslashit(), user_trailingslashit(), is_preview(), wp_unslash(), wp_unslash(), get_preview_post_link(), esc_url() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 104 instructions, 21–81 executed per call, 9 branches. 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.
Uses · 10
- get_post()Retrieves post data given a post ID or post object.
- get_permalink()Retrieves the full permalink for the current post or post ID.
- get_option()Retrieves an option value based on an option name.
- add_query_arg()Retrieves a modified URL query string.
- trailingslashit()Appends a trailing slash.
- user_trailingslashit()Retrieves a trailing-slashed string if the site is set for adding trailing slashes.
- is_preview()Determines whether the query is for a post or page preview.
- wp_unslash()Removes slashes from a string or recursively removes slashes from strings within an array.
- get_preview_post_link()Retrieves the URL used for the post preview.
- esc_url()Checks and cleans a URL.
Used by · 1
- wp_link_pages()The formatted output of a list of pages.
Source code
function _wp_link_page( $i ) { global $wp_rewrite; $post = get_post(); $query_args = array(); if ( 1 === $i ) { $url = get_permalink(); } else { if ( ! get_option( 'permalink_structure' ) || in_array( $post->post_status, array( 'draft', 'pending' ), true ) ) { $url = add_query_arg( 'page', $i, get_permalink() ); } elseif ( 'page' === get_option( 'show_on_front' ) && (int) get_option( 'page_on_front' ) === $post->ID ) { $url = trailingslashit( get_permalink() ) . user_trailingslashit( "$wp_rewrite->pagination_base/" . $i, 'single_paged' ); } else { $url = trailingslashit( get_permalink() ) . user_trailingslashit( $i, 'single_paged' ); } } if ( is_preview() ) { if ( ( 'draft' !== $post->post_status ) && isset( $_GET['preview_id'], $_GET['preview_nonce'] ) ) { $query_args['preview_id'] = wp_unslash( $_GET['preview_id'] ); $query_args['preview_nonce'] = wp_unslash( $_GET['preview_nonce'] ); } $url = get_preview_post_link( $post, $query_args, $url ); } return '<a href="' . esc_url( $url ) . '" class="post-page-numbers">';}Changelog
Introduced in 3.1.0. 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 6.7.7 tag, from
src/wp-includes/post-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.