PHP parse function call with parameters from string

Question

What is the best way to parse a string containing a function call with parameters in PHP so that I have the function name and the parameters with their correct types. Example:

$string = "ask('Do you want to continue?', ['yes', 'no'])";

I don't want to directly call that function, so eval is not an option. I want to do something based on the function name and use the parameters with their correct types. Is there an easy way in PHP?

I expect something like this as a result:

$name = 'ask';
$parameters = ['Do you want to continue?', ['yes', 'no']];

Nothing in PHP per se. You'd need to code that yourself. Have you tried anything so far?! — user8034901
– user8034901, Commented Feb 13, 2021 at 9:38
github.com/nikic/php-ast should be able to parse it to an AST. — Nigel Ren
– Nigel Ren, Commented Feb 13, 2021 at 9:41

trincot · Accepted Answer · 2021-02-13 10:15:48Z

1

Assuming that you want the arguments to be parsed to an array structure, you would still need to use eval (with all the precautions taken to ensure that the content is safe).

This code also assumes the format is as expected, i.e. it represents a valid function call, and the closing parenthesis is the final non-blank character:

$string = "ask('Do you want to continue?', ['yes', 'no'])";

$parts = array_map("trim", explode("(", substr(trim($string), 0, -1), 2));
$parts[1] = eval("return [$parts[1]];");

$parts will be:

[
    "ask",
    [
        "Do you want to continue?", 
        ["yes", "no"]
    ]
]

edited Feb 13, 2021 at 10:15

answered Feb 13, 2021 at 10:01

trincot

357k38 gold badges282 silver badges338 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Alexandr Blyakher · Accepted Answer · 2021-02-13 10:00:49Z

0

I think you should use one good library to parse PHP code. that is some example of that kind of library

use PhpParser\Error;
use PhpParser\NodeDumper;
use PhpParser\ParserFactory;

$code = <<<'CODE'
<?php

function test($foo)
{
    var_dump($foo);
}
CODE;

$parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7);
try {
    $ast = $parser->parse($code);
} catch (Error $error) {
    echo "Parse error: {$error->getMessage()}\n";
    return;
}

$dumper = new NodeDumper;
echo $dumper->dump($ast) . "\n";

https://github.com/nikic/PHP-Parser

answered Feb 13, 2021 at 10:00

Alexandr Blyakher

1804 bronze badges

1 Comment

Tom Piaggio Over a year ago

Could you add how would you convert the $ast to the actual needed output.

Collectives™ on Stack Overflow

PHP parse function call with parameters from string

2 Answers 2

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related