wp_allowed_protocols(): string[]
- Since
- 3.3.0, 4.3.0, 4.7.0, 5.3.0, 5.6.0
- Source
wp-includes/functions.php:7331
Compatibility
- WordPress
- since 5.6.0
- 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[]- Array of allowed protocols. Defaults to an array containing 'http', 'https', 'ftp', 'ftps', 'mailto', 'news', 'irc', 'irc6', 'ircs', 'gopher', 'nntp', 'feed', 'telnet', 'mms', 'rtsp', 'sms', 'svn', 'tel', 'fax', 'xmpp', 'webcal', and 'urn'.
This covers all common link protocols, except for 'javascript' which should not be allowed for untrusted users.
Performance profile
How much work a call to wp_allowed_protocols() 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
- 8–18
- Plugin surface
- 1 hook
- Called by
- 11
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 18.
Third-party callbacks on 'kses_allowed_protocols' run inside this call, and their cost is not bounded by anything here.
11 places 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
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_allowed_protocols() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
did_action() | 8–9 | did_action() |
!did_action() | 17–18 | did_action(), apply_filters(), 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: 18 instructions, 8–18 executed per call, 2 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.
Hooks and filters fired · 1
One hook fires while wp_allowed_protocols() runs, in this order:
- apply_filters( kses_allowed_protocols )filterline 7346 (+15 into the body)
Filters the list of protocols allowed in HTML attributes.
Uses · 2
- did_action()Retrieves the number of times an action has been fired during the current request.
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 11
- _links_add_base()Callback to add a base URL to relative links in passed content.
- _make_clickable_rel_attr()Helper function used to build the "rel" attribute for a URL when creating an anchor using make_clickable().
- edit_user()Edit user settings based on contents of $_POST
- esc_url()Checks and cleans a URL.
- safecss_filter_attr()Filters an inline style attribute and removes disallowed rules.
- wp_filter_oembed_iframe_title_attribute()Filters the given oEmbed HTML to make sure iframes have a title attribute.
- wp_is_internal_link()Determines whether or not the specified URL is of a host included in the internal hosts list.
- wp_kses()Filters text content and strips out disallowed HTML.
- wp_kses_one_attr()Filters one HTML attribute and ensures its value is allowed.
- wp_rel_callback()Callback to add a rel attribute to HTML A element.
- wp_targeted_link_rel_callback()Callback to add `rel="noopener"` string to HTML A element.
Source code
function wp_allowed_protocols() { static $protocols = array(); if ( empty( $protocols ) ) { $protocols = array( 'http', 'https', 'ftp', 'ftps', 'mailto', 'news', 'irc', 'irc6', 'ircs', 'gopher', 'nntp', 'feed', 'telnet', 'mms', 'rtsp', 'sms', 'svn', 'tel', 'fax', 'xmpp', 'webcal', 'urn' ); } if ( ! did_action( 'wp_loaded' ) ) { /** * Filters the list of protocols allowed in HTML attributes. * * @since 3.0.0 * * @param string[] $protocols Array of allowed protocols e.g. 'http', 'ftp', 'tel', and more. */ $protocols = array_unique( (array) apply_filters( 'kses_allowed_protocols', $protocols ) ); } return $protocols;}Changelog
Introduced in 3.3.0. 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/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
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