a2design-inc/upload

CakePHP plugin to handle file uploading sans ridiculous automagic


Keywords
upload, cakephp, Behavior, files
License
MIT

Documentation

Build Status Coverage Status Total Downloads Latest Stable Version

Upload Plugin 2.0

The Upload Plugin is an attempt to sanely upload files using techniques garnered packages such as MeioUpload , UploadPack and PHP documentation.

Background

Media Plugin is too complicated, and it was a PITA to merge the latest updates into MeioUpload, so here I am, building yet another upload plugin. I'll build another in a month and call it "YAUP".

Requirements

  • CakePHP 2.x
  • Imagick/GD PHP Extension (for Thumbnail Creation)
  • PHP5
  • Patience

Installation

[Using Composer]

View on Packagist, and copy the json snippet for the latest version into your project's composer.json. Eg, v. 1.0.0 would look like this:

{
    "require": {
        "josegonzalez/cakephp-upload": "1.0.0"
    }
}

Because this plugin has the type cakephp-plugin set in it's own composer.json, composer knows to install it inside your /Plugins directory, rather than in the usual vendors file. It is recommended that you add /Plugins/Upload to your .gitignore file. (Why? read this.)

[Manual]

[GIT Submodule]

In your app directory type:

git submodule add -b master git://github.com/josegonzalez/cakephp-upload.git Plugin/Upload
git submodule init
git submodule update

[GIT Clone]

In your Plugin directory type:

git clone -b master git://github.com/josegonzalez/cakephp-upload.git Upload

Imagick Support

To enable Imagick support, you need to have imagick installed:

# Debian systems
sudo apt-get install php-imagick

# OS X Homebrew
brew tap homebrew/dupes
brew tap josegonzalez/homebrew-php
brew install php54-imagick

# From pecl
pecl install imagick

If you cannot install imagick, please do not use imagick, and instead configure the plugin with 'thumbnailMethod' => 'php' in your setup options.

Enable plugin

In 2.0 you need to enable the plugin your app/Config/bootstrap.php file:

CakePlugin::load('Upload');

If you are already using CakePlugin::loadAll();, then this is not necessary.

Usage

CREATE table users (
    id int(10) unsigned NOT NULL auto_increment,
    username varchar(20) NOT NULL,
    photo varchar(255)
);

<?php
class User extends AppModel {
    public $actsAs = array(
        'Upload.Upload' => array(
            'photo'
        )
    );
}

<?php echo $this->Form->create('User', array('type' => 'file')); ?>
    <?php echo $this->Form->input('User.username'); ?>
    <?php echo $this->Form->input('User.photo', array('type' => 'file')); ?>
<?php echo $this->Form->end(); ?>

Using the above setup, uploaded files cannot be deleted. To do so, a field must be added to store the directory of the file as follows:

CREATE table users (
    `id` int(10) unsigned NOT NULL auto_increment,
    `username` varchar(20) NOT NULL,
    `photo` varchar(255) DEFAULT NULL,
    `photo_dir` varchar(255) DEFAULT NULL,
    PRIMARY KEY (`id`)
);

<?php
class User extends AppModel {
    public $actsAs = array(
        'Upload.Upload' => array(
            'photo' => array(
                'fields' => array(
                    'dir' => 'photo_dir'
                )
            )
        )
    );
}

In the above example, photo can be a file upload via a file input within a form, a file grabber (from a url) via a text input, OR programatically used on the controller to file grab via a url.

File Upload Example

<?php echo $this->Form->create('User', array('type' => 'file')); ?>
    <?php echo $this->Form->input('User.username'); ?>
    <?php echo $this->Form->input('User.photo', array('type' => 'file')); ?>
    <?php echo $this->Form->input('User.photo_dir', array('type' => 'hidden')); ?>
<?php echo $this->Form->end(); ?>

File Grabbing via Form Example

<?php echo $this->Form->create('User', array('type' => 'file')); ?>
    <?php echo $this->Form->input('User.username'); ?>
    <?php echo $this->Form->input('User.photo', array('type' => 'file')); ?>
    <?php echo $this->Form->input('User.photo_dir', array('type' => 'hidden')); ?>
<?php echo $this->Form->end(); ?>

Programmatic File Grab via Controller

$data['photo'] = $image_url;
$this->User->set($data);
$this->User->save();

Thumbnails are not automatically created. To do so, thumbnail sizes must be defined: Note: by default thumbnails will be generated by imagick, if you want to use GD you need to set the thumbnailMethod attribute. Example: 'thumbnailMethod' => 'php'.

<?php
class User extends AppModel {
    public $actsAs = array(
        'Upload.Upload' => array(
            'photo' => array(
                'fields' => array(
                    'dir' => 'photo_dir'
                ),
                'thumbnailSizes' => array(
                    'xvga' => '1024x768',
                    'vga' => '640x480',
                    'thumb' => '80x80'
                )
            )
        )
    );
}

Multiple files can also be attached to a single record:

<?php
class User extends AppModel {
    public $actsAs = array(
        'Upload.Upload' => array(
            'resume',
            'photo' => array(
                'fields' => array(
                    'dir' => 'profile_dir'
                ),
                'thumbnailSizes' => array(
                    'xvga' => '1024x768',
                    'vga' => '640x480',
                    'thumb' => '80x80'
                )
            )
        )
    );
}

PDF Support

It is now possible to generate a thumbnail for the first page of a PDF file. (Only works with the imagick thumbnailMethod.)

Please read about the Behavior options for more details as to how to configure this plugin.

Using a Polymorphic Attachment Model for File Storage

In some cases you will want to store multiple file uploads for a multiple models, but will not want to use multiple tables for some reason. For example, we might have a Post model that can have many images for a gallery, and a Message model that has many videos. In this case, we would use an Attachment model:

Post hasMany Attachment

We could use the following database schema for the Attachment model:

CREATE table attachments (
    `id` int(10) unsigned NOT NULL auto_increment,
    `model` varchar(20) NOT NULL,
    `foreign_key` int(11) NOT NULL,
    `name` varchar(32) NOT NULL,
    `attachment` varchar(255) NOT NULL,
    `dir` varchar(255) DEFAULT NULL,
    `type` varchar(255) DEFAULT NULL,
    `size` int(11) DEFAULT 0,
    `active` tinyint(1) DEFAULT 1,
    PRIMARY KEY (`id`)
);

Our attachment records would thus be able to have a name and be activated/de-activated on the fly. The schema is simply an example, and such functionality would need to be implemented within your application.

Once the attachments table has been created, we would create the following model:

<?php
class Attachment extends AppModel {
    public $actsAs = array(
        'Upload.Upload' => array(
            'attachment' => array(
                'thumbnailSizes' => array(
                    'xvga' => '1024x768',
                    'vga' => '640x480',
                    'thumb' => '80x80',
                ),
            ),
        ),
    );

    public $belongsTo = array(
        'Post' => array(
            'className' => 'Post',
            'foreignKey' => 'foreign_key',
        ),
        'Message' => array(
            'className' => 'Message',
            'foreignKey' => 'foreign_key',
        ),
    );
}

We would also need to present a valid counter-relationship in the Post model:

<?php
class Post extends AppModel {
    public $hasMany = array(
        'Image' => array(
            'className' => 'Attachment',
            'foreignKey' => 'foreign_key',
            'conditions' => array(
                'Image.model' => 'Post',
            ),
        ),
    );
}

The key thing to note here is the Post model has some conditions on the relationship to the Attachment model, where the Image.model has to be Post. Remember to set the model field to Post, or whatever model it is you'd like to attach it to, otherwise you may get incorrect relationship results when performing find queries.

We would also need a similar relationship in our Message model:

<?php
class Message extends AppModel {
    public $hasMany = array(
        'Video' => array(
            'className' => 'Attachment',
            'foreignKey' => 'foreign_key',
            'conditions' => array(
                'Video.model' => 'Message',
            ),
        ),
    );
}

Now that we have our models setup, we should create the proper actions in our controllers. To keep this short, we shall only document the Post model:

<?php
class PostsController extends AppController {
  /* the rest of your controller here */
  public function add() {
    if ($this->request->is('post')) {
      try {
        $this->Post->createWithAttachments($this->request->data);
        $this->Session->setFlash(__('The message has been saved'));
      } catch (Exception $e) {
        $this->Session->setFlash($e->getMessage());
      }
    }
  }
}

In the above example, we are calling our custom createWithAttachments method on the Post model. This will allow us to unify the Post creation logic together in one place. That method is outlined below:

<?php
class Post extends AppModel {
  /* the rest of your model here */

  public function createWithAttachments($data) {
    // Sanitize your images before adding them
    $images = array();
    if (!empty($data['Image'][0])) {
      foreach ($data['Image'] as $i => $image) {
        if (is_array($data['Image'][$i])) {
          // Force setting the `model` field to this model
          $image['model'] = 'Post';

          // Unset the foreign_key if the user tries to specify it
          if (isset($image['foreign_key'])) {
            unset($image['foreign_key']);
          }

          $images[] = $image;
        }
      }
    }
    $data['Image'] = $images;

    // Try to save the data using Model::saveAll()
    $this->create();
    if ($this->saveAll($data)) {
      return true;
    }

    // Throw an exception for the controller
    throw new Exception(__("This post could not be saved. Please try again"));
  }
}

The above model method will:

  • Ensure we only try to save valid images
  • Force the foreign_key to be unspecified. This will allow saveAll to properly associate it
  • Force the model field to Post

Now that this is set, we just need a view for our controller. A sample view for View/Posts/add.ctp is as follows (fields not necessary for the example are omitted):

<?php
  echo $this->Form->create('Post', array('type' => 'file'));
    echo $this->Form->input('Image.0.attachment', array('type' => 'file', 'label' => 'Image'));
    echo $this->Form->input('Image.0.model', array('type' => 'hidden', 'value' => 'Post'));
  echo $this->Form->end(__('Add'));
?>

The one important thing you'll notice is that I am not referring to the Attachment model as Attachment, but rather as Image; when I initially specified the $hasMany relationship between an Attachment and a Post, I aliased Attachment to Image. This is necessary for cases where many of your Polymorphic models may be related to each other, as a type of hint to the CakePHP ORM to properly reference model data.

I'm also using Model.{n}.field notation, which would allow you to add multiple attachment records to the Post. This is necessary for $hasMany relationships, which we are using for this example.

Once you have all the above in place, you'll have a working Polymorphic upload!

Please note that this is not the only way to represent file uploads, but it is documented here for reference.

Alternative Behaviors

The Upload plugin also comes with a FileImport behavior and a FileGrabber behavior.

FileImportBehavior

FileImportBehavior may be used to import files directly from the disk. This is useful in importing from a directory already on the filesystem.

Behavior options:

  • pathMethod: The method to use for file paths. This is appended to the path option below
    • Default: (string) primaryKey
    • Options:
      • flat: Does not create a path for each record. Files are moved to the value of the 'path' option.
      • primaryKey: Path based upon the record's primaryKey is generated. Persists across a record update.
      • random: Random path is generated for each file upload in the form nn/nn/nn where nn are random numbers. Does not persist across a record update.
      • randomCombined: Random path - with model id - is generated for each file upload in the form ID/nn/nn/nn where ID is the current model's ID and nn are random numbers. Does not persist across a record update.
  • path: A path relative to the APP_PATH. Should end in {DS}
    • Default: (string) '{ROOT}webroot{DS}files{DS}{model}{DS}{field}{DS}'
    • Tokens:
      • {ROOT}: Replaced by a rootDir option
      • {DS}: Replaced by a DIRECTORY_SEPARATOR
      • {model}: Replaced by the Model Alias.
      • {field}: Replaced by the field name.
      • {primaryKey}: Replaced by the record primary key, when available. If used on a new record being created, will have undefined behavior.
      • {size}: Replaced by a zero-length string (the empty string) when used for the regular file upload path. Only available for resized thumbnails.
      • {geometry}: Replaced by a zero-length string (the empty string) when used for the regular file upload path. Only available for resized thumbnails.
  • fields: An array of fields to use when uploading files
    • Default: (array) array('dir' => 'dir', 'type' => 'type', 'size' => 'size')
    • Options:
      • dir: Field to use for storing the directory
      • type: Field to use for storing the filetype
      • size: Field to use for storing the filesize
  • rootDir: Root directory for moving images. Auto-prepended to path and thumbnailPath where necessary
    • Default (string) ROOT . DS . APP_DIR . DS
  • mimetypes: Array of mimetypes to use for validation
    • Default: (array) empty
  • extensions: Array of extensions to use for validation
    • Default: (array) empty
  • maxSize: Max filesize in bytes for validation
    • Default: (int) 2097152
  • minSize: Minimum filesize in bytes for validation
    • Default: (int) 8
  • maxHeight: Maximum image height for validation
    • Default: (int) 0
  • minHeight: Minimum image height for validation
    • Default: (int) 0
  • maxWidth: Maximum image width for validation
    • Default: (int) 0
  • minWidth: Minimum image width for validation
    • Default: (int) 0
  • deleteOnUpdate: Whether to delete files when uploading new versions (potentially dangerous due to naming conflicts)
    • Default: (boolean) false
  • thumbnails: Whether to create thumbnails or not
    • Default: (boolean) true
  • thumbnailMethod: The method to use for resizing thumbnails
    • Default: (string) imagick
    • Options:
      • imagick: Uses the PHP imagick extension to generate thumbnails
      • php: Uses the built-in PHP methods (GD extension) to generate thumbnails. Does not support BMP images.
  • thumbnailName: Naming style for a thumbnail
    • Default: NULL
    • Note: The tokens {size} and {filename} are both valid for naming and will be auto-replaced with the actual terms.
    • Note: As well, the extension of the file will be automatically added.
    • Note: When left unspecified, will be set to {size}_{filename} or {filename}_{size} depending upon the value of thumbnailPrefixStyle
  • thumbnailPath: A path relative to the rootDir where thumbnails will be saved. Should end in {DS}. If not set, thumbnails will be saved at path.
    • Default: NULL
    • Tokens:
      • {ROOT}: Replaced by a rootDir option
      • {DS}: Replaced by a DIRECTORY_SEPARATOR
      • {model}: Replaced by the Model Alias
      • {field}: Replaced by the field name
      • {size}: Replaced by the size key specified by a given thumbnailSize
      • {geometry}: Replaced by the geometry value specified by a given thumbnailSize
  • thumbnailPrefixStyle: Whether to prefix or suffix the style onto thumbnails
    • Default: (boolean) true prefix the thumbnail
    • Note that this overrides thumbnailName when thumbnailName is not specified in your config
  • thumbnailQuality: Quality of thumbnails that will be generated, on a scale of 0-100. Not supported gif images when using GD for image manipulation.
    • Default: (int) 75
  • thumbnailSizes: Array of thumbnail sizes, with the size-name mapping to a geometry
    • Default: (array) empty
  • thumbnailType: Override the type of the generated thumbnail
    • Default: (mixed) false or png when the upload is a Media file
    • Options:
      • Any valid image type
  • mediaThumbnailType: Override the type of the generated thumbnail for a non-image media (pdfs). Overrides thumbnailType
    • Default: (mixed) png
    • Options:
      • Any valid image type
  • saveDir: Can be used to turn off saving the directory
    • Default: (boolean) true
    • Note: Because of the way in which the directory is saved, if you are using a pathMethod other than flat and you set saveDir to false, you may end up in situations where the file is in a location that you cannot predict. This is more of an issue for a pathMethod of random and randomCombined than primaryKey, but keep this in mind when fiddling with this option
  • mode: The UNIX permissions to set on the created upload directories.
    • Default: (integer) 0777

Thumbnail Sizes and Styles

Styles are the definition of thumbnails that will be generated for original image. You can define as many as you want.

<?php
class User extends AppModel {
    public $name = 'User';
    public $actsAs = array(
        'Upload.Upload' => array(
            'photo' => array(
                'thumbnailSizes' => array(
                    'big' => '200x200',
                    'small' => '120x120'
                    'thumb' => '80x80'
                )
            )
        )
    );
}

Styles only apply to images of the following types:

  • image/bmp
  • image/gif
  • image/jpeg
  • image/pjpeg
  • image/png
  • image/vnd.microsoft.icon
  • image/x-icon

You can specify any of the following resize modes for your sizes:

  • 100x80 - resize for best fit into these dimensions, with overlapping edges trimmed if original aspect ratio differs
  • [100x80] - resize to fit these dimensions, with white banding if original aspect ratio differs
  • 100w - maintain original aspect ratio, resize to 100 pixels wide
  • 80h - maintain original aspect ratio, resize to 80 pixels high
  • 80l - maintain original aspect ratio, resize so that longest side is 80 pixels
  • 600mw - maintain original aspect ratio, resize to max 600 pixels wide, or copy the original image if it is less than 600 pixels wide
  • 800mh - maintain original aspect ratio, resize to max 800 pixels high, or copy the original image if it is less than 800 pixels high
  • 960ml - maintain original aspect ratio, resize so that longest side is max 960 pixels, or copy the original image if the thumbnail would be bigger than the origina

Validation rules

By default, no validation rules are attached to the model. One must explicitly attach each rule if needed. Rules not referring to PHP upload errors are configurable but fallback to the behavior configuration.

isUnderPhpSizeLimit

Check that the file does not exceed the max file size specified by PHP

public $validate = array(
    'photo' => array(
        'rule' => 'isUnderPhpSizeLimit',
        'message' => 'File exceeds upload filesize limit'
    )
);

isUnderFormSizeLimit

Check that the file does not exceed the max file size specified in the HTML Form

public $validate = array(
    'photo' => array(
        'rule' => 'isUnderFormSizeLimit',
        'message' => 'File exceeds form upload filesize limit'
    )
);

isCompletedUpload

Check that the file was completely uploaded

public $validate = array(
    'photo' => array(
        'rule' => 'isCompletedUpload',
        'message' => 'File was not successfully uploaded'
    )
);

isFileUpload

Check that a file was uploaded

public $validate = array(
    'photo' => array(
        'rule' => 'isFileUpload',
        'message' => 'File was missing from submission'
    )
);

isFileUploadOrHasExistingValue

Check that either a file was uploaded, or the existing value in the database is not blank

public $validate = array(
    'photo' => array(
        'rule' => 'isFileUploadOrHasExistingValue',
        'message' => 'File was missing from submission'
    )
);

tempDirExists

Check that the PHP temporary directory is missing

public $validate = array(
    'photo' => array(
        'rule' => 'tempDirExists',
        'message' => 'The system temporary directory is missing'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('tempDirExists', false),
        'message' => 'The system temporary directory is missing'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isSuccessfulWrite

Check that the file was successfully written to the server

public $validate = array(
    'photo' => array(
        'rule' => 'isSuccessfulWrite',
        'message' => 'File was unsuccessfully written to the server'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isSuccessfulWrite', false),
        'message' => 'File was unsuccessfully written to the server'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

noPhpExtensionErrors

Check that a PHP extension did not cause an error

public $validate = array(
    'photo' => array(
        'rule' => 'noPhpExtensionErrors',
        'message' => 'File was not uploaded because of a faulty PHP extension'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('noPhpExtensionErrors', 1024, false),
        'message' => 'File was not uploaded because of a faulty PHP extension'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isValidMimeType

Check that the file is of a valid mimetype

public $validate = array(
    'photo' => array(
        'rule' => array('isValidMimeType', array('application/pdf', 'image/png')),
        'message' => 'File is not a pdf or png'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isValidMimeType', array('application/pdf', 'image/png'), false),
        'message' => 'File is not a pdf or png'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isWritable

Check that the upload directory is writable

public $validate = array(
    'photo' => array(
        'rule' => array('isWritable'),
        'message' => 'File upload directory was not writable'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isWritable', false),
        'message' => 'File upload directory was not writable'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isValidDir

Check that the upload directory exists

public $validate = array(
    'photo' => array(
        'rule' => array('isValidDir'),
        'message' => 'File upload directory does not exist'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isValidDir', false),
        'message' => 'File upload directory does not exist'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isBelowMaxSize

Check that the file is below the maximum file upload size (checked in bytes)

public $validate = array(
    'photo' => array(
        'rule' => array('isBelowMaxSize', 1024),
        'message' => 'File is larger than the maximum filesize'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isBelowMaxSize', 1024, false),
        'message' => 'File is larger than the maximum filesize'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isAboveMinSize

Check that the file is above the minimum file upload size (checked in bytes)

public $validate = array(
    'photo' => array(
        'rule' => array('isAboveMinSize', 1024),
        'message' => 'File is below the mimimum filesize'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isAboveMinSize', 1024, false),
        'message' => 'File is below the mimimum filesize'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isValidExtension

Check that the file has a valid extension

public $validate = array(
    'photo' => array(
        'rule' => array('isValidExtension', array('pdf', 'png', 'txt')),
        'message' => 'File does not have a pdf, png, or txt extension'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isValidExtension', array('pdf', 'png', 'txt'), false),
        'message' => 'File does not have a pdf, png, or txt extension'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isAboveMinHeight

Check that the file is above the minimum height requirement (checked in pixels)

public $validate = array(
    'photo' => array(
        'rule' => array('isAboveMinHeight' 150),
        'message' => 'File is below the minimum height'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isAboveMinHeight', 150, false),
        'message' => 'File is below the minimum height'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isBelowMaxHeight

Check that the file is below the maximum height requirement (checked in pixels)

public $validate = array(
    'photo' => array(
        'rule' => array('isBelowMaxHeight', 150),
        'message' => 'File is above the maximum height'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isBelowMaxHeight', 150, false),
        'message' => 'File is above the maximum height'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isAboveMinWidth

Check that the file is above the minimum width requirement (checked in pixels)

public $validate = array(
    'photo' => array(
        'rule' => array('isAboveMinWidth', 150),
        'message' => 'File is below the minimum width'
    )
);

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isAboveMinWidth', 150, false),
        'message' => 'File is below the minimum width'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

isBelowMaxWidth

Check that the file is below the maximum width requirement (checked in pixels) public $validate = array( 'photo' => array( 'rule' => array('isBelowMaxWidth', 150), 'message' => 'File is above the maximum width' ) );

If the argument $requireUpload is passed, we can skip this check when a file is not uploaded:

public $validate = array(
    'photo' => array(
        'rule' => array('isBelowMaxWidth', 150, false),
        'message' => 'File is above the maximum width'
    )
);

In the above, the variable $requireUpload has a value of false. By default, requireUpload is set to true.

Remove a current file without deleting the entire record

In some cases you might want to remove a photo or uploaded file without having to remove the entire record from the Model. In this case you would use the following code:

<?php
echo $this->Form->create('Model', array('type' => 'file'));
echo $this->Form->input('Model.file.remove', array('type' => 'checkbox', 'label' => 'Remove existing file'));

License

The MIT License (MIT)

Copyright (c) 2010 Jose Diaz-Gonzalez

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.