abstract syntax tree - How to use PHP-Parser to get the global variables name and change it

Hey there!

I've also had my fair share of experience using PHP-Parser to analyze and modify PHP code, so I can definitely share some insights on your question.

To retrieve global variable names from the AST and apply changes, you can leverage the power of PHP-Parser and its visitor pattern capability. Here's an approach you can take:

php
class GlobalVariableVisitor extends PhpParser\NodeVisitorAbstract

{

    public $globalVariables = [];



    public function enterNode(PhpParser\Node $node)

    {

        if ($node instanceof PhpParser\Node\Expr\Variable && $this->isGlobalVariable($node)) {

            $this->globalVariables[] = $node->name->name;

        }

    }



    private function isGlobalVariable(PhpParser\Node\Expr\Variable $node): bool

    {

        $parentNode = $node->getAttribute('parent');

        

        if ($parentNode instanceof PhpParser\Node\Stmt\Global_) {

            return true;

        }



        // Add more conditions to determine if the variable is global

        // For instance, you can check if it's outside any function or class



        return false;

    }

}



$code = "..."; // Your PHP code snippet goes here



$parser = (new PhpParser\ParserFactory)->create(PhpParser\ParserFactory::PREFER_PHP7); // Adjust PHP version if required

$traverser = new PhpParser\NodeTraverser();



$globalVisitor = new GlobalVariableVisitor();

$traverser->addVisitor($globalVisitor);



$ast = $parser->parse($code);

$traverser->traverse($ast);



$globalVariables = $globalVisitor->globalVariables; // Store the global variable names



foreach ($globalVariables as $variable) {

    // Go ahead and make the desired modifications to the global variables

    // You can update their names or implement any other changes as per your requirements

}

Hello!

I've had the opportunity to work with PHP-Parser in a similar scenario, and I can definitely assist you with your question.

To extract global variable names from the AST and apply modifications, you can implement a visitor pattern using PHP-Parser. Here's how you can go about it:

php
class GlobalVariableVisitor extends PhpParser\NodeVisitorAbstract

{

    public $globalVariables = [];



    public function enterNode(PhpParser\Node $node)

    {

        if ($node instanceof PhpParser\Node\Expr\Variable && $this->isGlobalVariable($node)) {

            $this->globalVariables[] = $node->name->name;

        }

    }



    private function isGlobalVariable(PhpParser\Node\Expr\Variable $node): bool

    {

        $parent = $node->getAttribute('parent');

        

        // Check if variable is global based on parent node

        if ($parent instanceof PhpParser\Node\Stmt\Global_) {

            return true;

        }



        // You can add more conditions to determine global variables, like checking if it's outside any function or class



        return false;

    }

}



$code = "..."; // Insert your PHP code here



$parser = (new PhpParser\ParserFactory)->create(PhpParser\ParserFactory::PREFER_PHP7); // Adjust PHP version if needed

$traverser = new PhpParser\NodeTraverser();



$globalVisitor = new GlobalVariableVisitor();

$traverser->addVisitor($globalVisitor);



$ast = $parser->parse($code);

$traverser->traverse($ast);



$globalVariables = $globalVisitor->globalVariables; // Contains global variable names



foreach ($globalVariables as $variable) {

    // Perform your desired modifications to the global variables

    // You can change the variable name or apply any other necessary changes

}

Related Topics

• Setting Fake/local IP address To PHP $_SERVER variable
• JavaScript to PHP variable value pass error (document.write command is not working)
• session - Undefined variable: _SESSION in php?
• Store hex color value in variable and convert it into JPEG in PHP
• How to strip html tags and leave link from a variable in php
• Set html text box value from php variable
• PHP Curl COQL Select Query works with string but fails with Variable
• How can I pass variable to check plagiarism in Copyleaks API using PHP.? Here is my Code. I have just implement API in php code yet
• html - Changing text to image with php variables
• cant include skript or variable in php

Hey there,

I've actually used PHP-Parser for a similar purpose before. To get the names of global variables from the AST, you can make use of the Visitor pattern provided by PHP-Parser.

Here's how you can do it:

php
class GlobalVarVisitor extends PhpParser\NodeVisitorAbstract

{

    public $globalVariables = [];



    public function enterNode(PhpParser\Node $node)

    {

        if ($node instanceof PhpParser\Node\Expr\Variable && $node->name instanceof PhpParser\Node\Identifier) {

            $this->globalVariables[] = $node->name->name;

        }

    }

}



$code = "..."; // Your PHP code here



$parser = (new PhpParser\ParserFactory)->create(PhpParser\ParserFactory::PREFER_PHP7); // Adjust the PHP version based on your code

$traverser = new PhpParser\NodeTraverser;



$visitor = new GlobalVarVisitor;

$traverser->addVisitor($visitor);



$ast = $parser->parse($code);

$traverser->traverse($ast);



$globalVariables = $visitor->globalVariables; // Array of global variable names



foreach ($globalVariables as $variable) {

    // Perform your modifications to the global variables here

    // For example, you can change the variable name to something else

}

More Topics Related to PHP

• What are the recommended PHP versions for different operating systems?
• Can I install PHP without root/administrator access?
• How can I verify the integrity of the PHP installation files?
• Are there any specific considerations when installing PHP on a shared hosting environment?
• Is it possible to install PHP alongside other programming languages like Python or Ruby?

More Topics Related to Global Variables

• How do local variables differ from global variables in PHP?
• Can I access a global variable inside a function in PHP?
• How do I create and access variables within different functions in PHP?
• Is it possible to List Out All the Global variables in PHP?
• What is the difference between "GLOBAL" and "STATIC" variable in PHP?

More Topics Related to Code Analysis

• php - How to declare the type for local variables using PHPDoc notation?
• abstract syntax tree - How to use PHP-Parser to get the global variables name and change it
• How do attributes interact with PHP IDEs and development tools, and can they enhance the developer experience?