wppaste
WordPress

get_post_field( string $field, int|WP_Post $post = null, string $context = 'display' ): string

Since
2.3.0, 4.5.0
Source
wp-includes/post.php:1180
Retrieves data from a post field based on Post ID.

Description

Examples of the post field will be, 'post_type', 'post_status', 'post_content', etc and based off of the post object property or key names.

The context values are based off of the taxonomy filter functions and supported values are found within those functions.

Compatibility

WordPress
since 4.5.0
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

$fieldstring
Post field name.
$postint|WP_Postoptional
Post ID or post object. Defaults to global $post.Default: null
$contextstringoptional
How to filter the field. Accepts 'raw', 'edit', 'db', or 'display'. Default 'display'.Default: 'display'

Return value

string
The value of the post field on success, empty string on failure.

Performance profile

How much work a call to get_post_field() 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

Reaches the database via get_post().

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
9–21

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 23.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
7

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

What it touches

  • querycontent queryget_post()called directly
  • hookthird-party callbacksapply_filters()one call below get_post_field()

Further down the call graph this can also reach option, cache, serialize 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 get_post_field() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always9–11get_post()
isset($post->field)21get_post(), sanitize_post_field()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 23 instructions, 9–21 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.

Uses · 2

Used by · 7

Source code

View on Trac View on GitHub 

function get_post_field( $field, $post = null, $context = 'display' ) {	$post = get_post( $post ); 	if ( ! $post ) {		return '';	} 	if ( ! isset( $post->$field ) ) {		return '';	} 	return sanitize_post_field( $field, $post->$field, $post->ID, $context );}

Changelog

Introduced in 2.3.0. One change between 6.7.7 and 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.

6.9.7
Return type changed from string to int|string|int[].verified against source
4.5.0
The $post parameter was made optional.from the docblock
2.3.0
Introduced.from the docblock

About this page

Parsed data
Generated from the wordpress-develop 6.7.7 tag, from src/wp-includes/post.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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