make_url_footnote( string $content ): string

Description

Compatibility

Deprecated in WordPress 2.9.0. Kept for back-compatibility; avoid it in new code.

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$contentstring

Content to get links.

Return value

string

HTML stripped out of content with links at the bottom.

Performance profile

How much work a call to make_url_footnote() 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

Reads stored settings via get_option(), cached per request but not free on a cold cache.

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

24

Executed per call on PHP 8.5. The body compiles to 68.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

• optionoption read or writeget_option()called directly
• regexregular expression over the whole inputpreg_match_all()called directly
• hookthird-party callbacksdo_action()one call below make_url_footnote()
• cacheobject cachewp_cache_get()one call below make_url_footnote()
• serializeserialisationmaybe_unserialize()one call below make_url_footnote()

Further down the call graph this can also reach 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 · 1 distinct outcome

One number would be a lie: the work depends on which branch runs. These are every distinct cost make_url_footnote() can have, taken from its control-flow graph on PHP 8.5.

Uses · 2

• _deprecated_function()Marks a function as deprecated and inform when it has been used.
• get_option()Retrieves an option value based on an option name.

Used by · 1

• the_content_rss()Display the post content for the feed.

Source code

View on Trac ↗View on GitHub ↗

1734function make_url_footnote( $content ) {1735	_deprecated_function( __FUNCTION__, '2.9.0', '' );1736	preg_match_all( '/<a(.+?)href=\"(.+?)\"(.*?)>(.+?)<\/a>/', $content, $matches );1737	$links_summary = "\n";1738	for ( $i = 0, $c = count( $matches[0] ); $i < $c; $i++ ) {1739		$link_match = $matches[0][$i];1740		$link_number = '['.($i+1).']';1741		$link_url = $matches[2][$i];1742		$link_text = $matches[4][$i];1743		$content = str_replace( $link_match, $link_text . ' ' . $link_number, $content );1744		$link_url = ( ( strtolower( substr( $link_url, 0, 7 ) ) !== 'http://' ) && ( strtolower( substr( $link_url, 0, 8 ) ) !== 'https://' ) ) ? get_option( 'home' ) . $link_url : $link_url;1745		$links_summary .= "\n" . $link_number . ' ' . $link_url;1746	}1747	$content  = strip_tags( $content );1748	$content .= $links_summary;1749	return $content;1750}

Changelog

Introduced in 0.71. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.9.7 tag, from src/wp-includes/deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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