You should be able to use an Anonymous Function (aka Closure) with a call to the parent scoped$delimiter
variable, like so:
$callbacks[$delimiter] = function($matches) use ($delimiter) {
return $delimiter . strtolower($matches[1]);
};
I would like to contribute with a very simple case I found in a Wordpress Theme and seems to work properly:
Having the following add_filter statement:
add_filter( 'option_page_capability_' . ot_options_id(), create_function( '$caps', "return '$caps';" ), 999 );
Replace it for:
add_filter( 'option_page_capability_' . ot_options_id(), function($caps) {return $caps;},999);
We can see the usage of function(), very typical function creation instead of a deprecated create_function() to create functions.
If anyone needs to upgrade dozens ofcreate_function()
cases in their code to anonymous functions, I work on a tool called Rector.
It goes through the code and replaces thecreate_function
with anonymous functions 1:1. It's tested on 30 various cases.
Install
composer require rector/rector --dev
Setup
Let's say you want to upgrade code in the/src
directory.
# rector.php
<?php
use Rector\Core\Configuration\Option;
use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
use Rector\Php72\Rector\FuncCall\CreateFunctionToAnonymousFunctionRector;
return static function (ContainerConfigurator $containerConfigurator) {
$parameters = $containerConfigurator->parameters();
$parameters->set(Option::PATHS, [
__DIR__ . '/src',
]);
$services = $containerConfigurator->services();
$services->set(CreateFunctionToAnonymousFunctionRector::class);
};
Run on your code
# this is set run, it only report what it would change
vendor/bin/rector process --config rector.php --dry-run
# this actually changes the code
vendor/bin/rector process --config rector.php
# the "rector.php" config is loaded by default, so we can drop it
vendor/bin/rector process
EDIT: Updated 2020-10-31 with PHP Rector 0.8.x syntax
Since PHP 7.4 you can use an Arrow function:
$callbacks[$delimiter] = fn($matches) => $delimiter . strtolower($matches[1]);
Arrow functions are shorter than anonymous functions, and use the parent scope - so you can refer to $delimiter without passing it in.
This Array of Anonymous functions worked for me, see code below:
// This will be a dynamic name that could
// be used as a function like "namespace".
$dynamic_name = 'my_dynamic_name';
// Here's some variables that you could use in the scope of
// your dynamic anonymous functions.
$outerVariable = 'If I need this varible, I can use it';
$outerVariableTwo = 'If I need this varible, I can use it too!';
// Create an array that we can later use and turn into
// and associative array with our new dynamic anonymous functions.
$dynamicAnonFunctions = [];
// Create the first dynamic function.
$dynamicAnonFunctions[($dynamic_name."_func_one")] = function () use ($outerVariable, $dynamic_name) {
echo 'Running: function <b>'.$dynamic_name .'_func_one()</b>';
echo '<br><br>';
echo $outerVariable;
echo '<br><br>';
echo 'This works :)';
echo '<br><br>';
};
// Create the second dynamic function
$dynamicAnonFunctions[($dynamic_name."_func_two")] = function () use ($outerVariableTwo, $dynamic_name) {
echo '- - - - - - - - - - - - - - - - - - - ';
echo '<br><br>';
echo 'Running: function <b>'.$dynamic_name .'_func_two()</b>';
echo '<br><br>';
echo $outerVariableTwo;
echo '<br><br>';
echo 'This also works :)!';
echo '<br><br>';
};
// Call the functions.
$dynamicAnonFunctions[($dynamic_name."_func_one")]();
$dynamicAnonFunctions[($dynamic_name."_func_two")]();
// Halt execution.
exit();
Just copy this into your script file and you will see the output from theecho
statements, then simply remap the function to your own will!
Happy coding =)
The anonymous function solution works, but if the expression to be returned is in a string I thinkeval
should be used.
$callbacks[$delimiter] = eval('return function($matches){return '.$delimiter.' . strtolower($matches[1]);};');
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PHP (from the English Hypertext Preprocessor - hypertext preprocessor) is a scripting programming language for developing web applications. Supported by most hosting providers, it is one of the most popular tools for creating dynamic websites.
The PHP scripting language has gained wide popularity due to its processing speed, simplicity, cross-platform, functionality and distribution of source codes under its own license.
https://www.php.net/
Symfony compares favorably with other PHP frameworks in terms of reliability and maturity. This framework appeared a long time ago, in 2005, that is, it has existed much longer than most of the other tools we are considering. It is popular for its web standards compliance and PHP design patterns.
https://symfony.com/
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