wp_json_file_decode( string $filename, array $options = array() ): mixed

Compatibility

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

Parameters

$filenamestring

Path to the JSON file.

$optionsarrayoptional

Options to be used with json_decode().Default: array()

• $associativebooldefault: false

  Optional. When true, JSON objects will be returned as associative arrays. When false, JSON objects will be returned as objects.

Return value

mixed

Returns the value encoded in JSON in appropriate PHP type.
null is returned if the file is not found, or its content can't be decoded.

Performance profile

How much work a call to wp_json_file_decode() 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 or writes the filesystem via file_get_contents().

Scaling

Constant

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

Instructions

22–43

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 56.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

5

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

What it touches

• serializeserialisationjson_decode()called directly
• filesystemfilesystem accessfile_get_contents()called directly
• hookthird-party callbacksdo_action()one call below wp_json_file_decode()

Further down the call graph this can also reach query, option, cache 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 · 3 distinct outcomes

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

Uses · 4

• wp_normalize_path()Normalizes a filesystem path.
• wp_trigger_error()Generates a user-level error/warning/notice/deprecation message.
• __()Retrieves the translation of $text.
• wp_parse_args()Merges user defined arguments into defaults array.

Used by · 5

• WP_Font_Collection::load_from_file()Loads the font collection data from a JSON file path.
• WP_Theme_JSON_Resolver::read_json_file()Processes a file that adheres to the theme.json schema and returns an array with its contents, or a void array if none found.
• WP_Theme_JSON_Resolver::translate()Given a theme.json structure modifies it in place to update certain values by its translated strings according to the language set by the user.
• get_block_metadata_i18n_schema()Gets i18n schema for block's metadata read from `block.json` file.
• register_block_type_from_metadata()Registers a block type from the metadata stored in the `block.json` file.

Source code

View on Trac ↗View on GitHub ↗

4725function wp_json_file_decode( $filename, $options = array() ) {4726	$result   = null;4727	$filename = wp_normalize_path( realpath( $filename ) );4728 4729	if ( ! $filename ) {4730		wp_trigger_error(4731			__FUNCTION__,4732			sprintf(4733				/* translators: %s: Path to the JSON file. */4734				__( "File %s doesn't exist!" ),4735				$filename4736			)4737		);4738		return $result;4739	}4740 4741	$options      = wp_parse_args( $options, array( 'associative' => false ) );4742	$decoded_file = json_decode( file_get_contents( $filename ), $options['associative'] );4743 4744	if ( JSON_ERROR_NONE !== json_last_error() ) {4745		wp_trigger_error(4746			__FUNCTION__,4747			sprintf(4748				/* translators: 1: Path to the JSON file, 2: Error message. */4749				__( 'Error when decoding a JSON file at path %1$s: %2$s' ),4750				$filename,4751				json_last_error_msg()4752			)4753		);4754		return $result;4755	}4756 4757	return $decoded_file;4758}

Changelog

Introduced in 5.9.0. 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 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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