Attachment component for CakePHP handles file uploads to the file system. If
it’s an image file, it creates thumbnail copies in
/app/webroot/attachments/photos/{required_sizes} folder; while other files
are stored in /app/webroot/attachments/files.

I’ve started it from the public copy at
https://sabbour.wordpress.com/2008/07/18/enhanced-image-upload-component-for-cakephp-12/
to have a standard way of uploading files to CakePHP projects.

See branch cake1.3 for Cake 1.3 version; branch cake2 for CakePHP 2 version.

1. PHP GD library installed and enabled.
2. /app/webroot/attachments/ must be writable by the web server.

1. Copy attachment.php to /app/controllers/components/
2. Add component to your controller: var $components = array('Attachment');
3. Add DB columns {prefix}_file_path, {prefix}_file_name, {prefix}_file_size
   and {prefix}_content_type to the model. The prefix is the model name, in
   lowercase, words seperated by underscores.

We’ll asume a Model named ‘Pet’ for a sample installation. The code relies on
four columns in the Model table:

pet_file_path, pet_file_name, pet_file_size and pet_content_type

Models with multi-word names should have each word seperated by underscores.
For example, the model “GalleryPhoto” would use the table “gallery_photos” and
the following fields:

gallery_photo_file_path, gallery_photo_file_name, gallery_photo_file_size and gallery_photo_content_type

These fields are automagically updated when you call save() on the $this->data array

<?= $this->Form->create('Pet', array('type' => 'file'));
<?= $this->Form->input('pet' , array('type' => 'file')); ?>
<?= $this->Form->end('Save my pooch'); ?>

The (file) input ‘pet’ is the lower case model-name, multi-word model names
seperated by underscores.

For images: <?= $this->Html->image('/attachments/files_dir/{size}/' . $data['Pet']['pet_file_path']); ?>
For files: <?= $this->Html->link('Grab file', '/attachments/files_dir/' . $data['Pet']['pet_file_path']); ?>

Configuration options (default values between parentheses):

• files_dir: Where to save the files (inside /app/webroot/attachments/) (photos).
• rm_tmp_file: Remove temporal image after resizing (false).
• allow_non_image_files, self descriptive ;-) (true).
• default_col: Column prefix for file related data (lowercase modelname, words seperated by underscores).
• images_size: Array of different file sizes required by your app. Each
  element is itself an array, like: 'folder_name' => array($width, $height, $crop).
  (You may define only width or height, and the image will scale appropriately).

You can override the default configuration passing an array of options while
including the component, like:

var $components = array('Attachment' => array( 'files_dir' => 'pets', 'images_size' => array( 'avatar' => array(75, 75, 'resizeCrop') ) ));

• data: Raw data from form.

Simply call the following on the form data:

$this->Attachment->upload($this->data['Pet']);

You may choose different column prefixes than the model name, as long as you
specify it on the upload method, like so:

$this->Attachment->upload($this->data['Pet'], 'dog');

Used by the more general upload method.

• data: image data array
• upload_dir: where to save the file (inside attachments/files_dir)
• maxw/maxh: maximum width/height for resizing images
• crop: Crop image? (one of resize, resizeCrop or crop)

• filename: file-to-delete name

You may wish to validate from the model. e.g:

var $validate = array(
'pet_file_size' => array(
'rule' => array('maxLength', 6),
'message' => 'Image size is waaaaaayyy too big. Try resizing first'
)
);

if(isset($this->Form->validationErrors)) {
foreach ($this->Form->validationErrors as $model => $columns) {
foreach ($columns as $err_msg) {
echo $this->Html->div('error-message', $err_msg);
}
}
}

if (isset($this->Form->validationErrors['Pet']['pet_file_name'])) {
echo $this->Html->div('error-message', $this->Form->validationErrors['Pet']['pet_file_name']);
}