Error Handling

• Image Exceptions
  • LogicExceptions
  • RuntimeExceptions

Image Exceptions

If something goes wrong, Intervention Image throws exceptions. For this purpose, a structured hierarchy has been implemented.

All exceptions are extended from a container the container class Intervention\Image\Exceptions\ImageException. This makes it possible to catch all errors in the library in general.

The container class is divided into two types: LogicException and RuntimeException indicating and operational failure or that the error can be fixed by correcting the code.

These two types are each divided into further sub-branches. Adding the possibility to intercept every type of error in detail and respond accordingly.

ImageException
├── LogicException
│   ├── ArgumentException
│   │   └── InvalidArgumentException
│   ├── NotSupportedException
│   └── StateException
│
└── RuntimeException
    ├── MissingDependencyException
    ├── FilesystemException
    │   ├── DirectoryNotFoundException
    │   ├── StreamException
    │   ├── FileNotFoundException
    │   ├── FileNotReadableException
    │   └── FileNotWritableException
    └── DriverException
        ├── AnalyzerException
        ├── ModifierException
        ├── DecoderException
        │   ├── ImageDecoderException
        │   └── ColorDecoderException
        └── EncoderException

LogicExceptions

Exceptions of type Intervention\Image\LogicException mean that the API was not addressed correctly, i.e., there is an error in the end user's code. There are further sub-types.

ArgumentException / InvalidArgumentException

This exceptions are thrown when a argument passed does not match the expected format. For example, if a negative value is specified for an image width.

NotSupportedException

This type of exception indicates that something was requested that lacks general support. For example, when an image is to be converted to a color space that is not implemented for the driver.

StateException

This type of exception indicates that something is not in the correct state for the requested operation. For example when you try to decode an image but there are no decoders in the handler stack.

RuntimeExceptions

RuntimeException means operational failure. Usually occurs when something internal goes wrong. See the following sub-types for better understanding.

MissingDependencyException

This exception indicates that a dependency is not been met. For example when you try to use the driver for Imagick but forgot to install the matching PHP extension.

FilesystemException

This extension is thrown when something went wrong in the filesystem. This can have various causes. For example, a file cannot be read because it does not exist or there are no permissions to do so. Or a directory cannot be written to because it does not exist.

There is an exception type for each of these individual cases.

• Intervention\Image\Exceptions\DirectoryNotFoundException
• Intervention\Image\Exceptions\StreamException
• Intervention\Image\Exceptions\FileNotFoundException
• Intervention\Image\Exceptions\FileNotReadableException
• Intervention\Image\Exceptions\FileNotWritableException

DriverException

This exception is thrown when the underlying image extension produces an error. It is divided into four sub-types, each dealing with a specific driver operation.

• Intervention\Image\Exceptions\AnalyzerException
• Intervention\Image\Exceptions\ModifierException
• Intervention\Image\Exceptions\DecoderException
• Intervention\Image\Exceptions\EncoderException