A better PHP backtrace

To get the backtrace in PHP you can use the debug_backtrace function. By default, it can be hard to work with. The reported function name for a frame is skewed: it belongs to the previous frame. Also, options need to be passed using a bitmask.

This package provides a better way than debug_backtrace to work with a back trace. Here's an example:

// returns an array with `Spatie\Backtrace\Frame` instances
$frames = Spatie\Backtrace\Backtrace::create()->frames(); 

$firstFrame = $frames[0];

$firstFrame->file; // returns the file name
$firstFrame->lineNumber; // returns the line number
$firstFrame->class; // returns the class name

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Installation

You can install the package via composer:

composer require spatie/backtrace

Usage

This is how you can create a backtrace instance:

$backtrace = Spatie\Backtrace\Backtrace::create();

Getting the frames

To get all the frames you can call frames.

$frames = $backtrace->frames(); // contains an array with `Spatie\Backtrace\Frame` instances

A Spatie\Backtrace\Frame has these properties:

• file: the name of the file
• lineNumber: the line number
• arguments: the arguments used for this frame. Will be null if withArguments was not used.
• class: the class name for this frame. Will be null if the frame concerns a function.
• method: the method used in this frame
• applicationFrame: contains true is this frame belongs to your application, and false if it belongs to a file in the vendor directory

Collecting arguments

For performance reasons, the frames of the back trace will not contain the arguments of the called functions. If you want to add those use the withArguments method.

$backtrace = Spatie\Backtrace\Backtrace::create()->withArguments();

Reducing arguments

For viewing purposes, arguments can be reduced to a string:

$backtrace = Spatie\Backtrace\Backtrace::create()->withArguments()->reduceArguments();

By default, some typical types will be reduced to a string. You can define your own reduction algorithm per type by implementing an ArgumentReducer:

class DateTimeWithOtherFormatArgumentReducer implements ArgumentReducer
{
    public function execute($argument): ReducedArgumentContract
    {
        if (! $argument instanceof DateTimeInterface) {
            return UnReducedArgument::create();
        }

        return new ReducedArgument(
            $argument->format('d/m/y H:i'),
            get_class($argument),
        );
    }
}

This is a copy of the built-in argument reducer for DateTimeInterface where we've updated the format. An UnReducedArgument object is returned when the argument is not of the expected type. A ReducedArgument object is returned with the reduced value of the argument and the original type of the argument.

The reducer can be used as such:

$backtrace = Spatie\Backtrace\Backtrace::create()->withArguments()->reduceArguments(
    Spatie\Backtrace\Arguments\ArgumentReducers::default([
        new DateTimeWithOtherFormatArgumentReducer()
    ])
);

Which will first execute the new reducer and then the default ones.

Setting the application path

You can use the applicationPath to pass the base path of your app. This value will be used to determine whether a frame is an application frame, or a vendor frame. Here's an example using a Laravel specific function.

$backtrace = Spatie\Backtrace\Backtrace::create()->applicationPath(base_path());

Getting a certain part of a trace

If you only want to have the frames starting from a particular frame in the backtrace you can use the startingFromFrame method:

use Spatie\Backtrace\Backtrace;
use Spatie\Backtrace\Frame;

$frames = Backtrace::create()
    ->startingFromFrame(function (Frame $frame) {
        return $frame->class === MyClass::class;
    })
    ->frames();

With this code, all frames before the frame that concerns MyClass will have been filtered out.

Alternatively, you can use the offset method, which will skip the given number of frames. In this example the first 2 frames will not end up in $frames.

$frames = Spatie\Backtrace\Backtrace::create()
    ->offset(2)
    ->frames();

Limiting the number of frames

To only get a specific number of frames use the limit function. In this example, we'll only get the first two frames.

$frames = Spatie\Backtrace\Backtrace::create()
    ->limit(2)
    ->frames();

Getting a backtrace for a throwable

Here's how you can get a backtrace for a throwable.

$frames = Spatie\Backtrace\Backtrace::createForThrowable($throwable)

Because we will use the backtrace that is already available the throwable, the frames will always contain the arguments used.

Testing

composer test

Changelog

Please see CHANGELOG for more information on what has changed recently.

Contributing

Please see CONTRIBUTING for details.

Security Vulnerabilities

Please review our security policy on how to report security vulnerabilities.

Credits

• Freek Van de Herten
• All Contributors

License

The MIT License (MIT). Please see License File for more information.