Yii – Rewrite file or image urls for download or display

I recently had a need to track files and images which were uploaded and for their urls to be secret. This meant that they couldn’t sit in a folder waiting to be found and had to be saved below the site root.

To get access to them I wanted to the check the user permissions followed by forcing download of all files (including images). Here are the steps I took to accomplish this…

For the sake of this page, my (fake) file urls are something like:

example.com/user/123/file/456.pdf

Update the urlmanager to rewrite files to my filemanager/view:


	'user//file/.[a-z0-9]+' => 'filemanager/view',

Update the filemanager class’ actionView function:


	public function actionView($id)
	{
		$file = $this->loadModel($id);

		header("Pragma: public"); // required
		header("Expires: 0");
		header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
		header("Cache-Control: private",false); // required for certain browsers 
		//header("Content-Type: " . $file->mime_type);
		header("Content-Disposition: attachment; filename=\"" . str_replace(" ", "-", preg_replace("@[^a-z0-9 ]@", "", strtolower($file->file_name))) . '.' . $file->file_extension . "\";" );
		header("Content-Transfer-Encoding: binary");
		header("Content-Length: ".filesize(Yii::app()->basePath . '/../../uploads/user_files/' . $file->file_id . '.' . $file->file_extension));
		readfile(Yii::app()->basePath . '/../../uploads/user_files/' . $file->file_id . '.' . $file->file_extension);
		exit();

	}

I also of course required filemanager access to be strict:


	public function accessRules()
	{
		return array(
			array('allow', 
				'actions'=>array('view', 'create','delete'),
				'users'=>array(),
				'expression' => 'User::model()->hasRightsToFile()',
			),
			array('deny',  // deny all users
				'users'=>array('*'),
			),
		);
	}

And that’s about it. Controlled and forced file download with rewritten file urls.

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Yii – Only fill filter dropdown with used options

Sometimes you want to show a filter dropdown but by default it will show all value options even if not assigned to anything. You can use findAll with criteria to only bring back items which are in use…


$criteria = new CDbCriteria;
$criteria->join = 'INNER JOIN organisation ON organisation.category_id = t.category_id';

if($_GET['school_id'])
{
	$criteria->condition = 'organisation.school_id = ' . $_GET['school_id'];
}
else
{

}

$categories = OrganisationCategory::model()->findAll($criteria);
$categories_array = array();
foreach($categories as $category)
{
	$categories_array[$category->category_id] = $category->name;
}


$columns = array(
	'name',
	array(
		'name'=>'category_id',
		'value' => 'OrganisationCategory::model()->findByPk($data->category_id)->name',
		'filter' => $categories_array
[...]

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Yii CGridView default Order

If you want to set a default sort order for a CGridView, often used in admin views you can do so in the controller as part of the search() function:

$dataProvider = new CActiveDataProvider(get_class($this), array(
	'criteria'=>$criteria,
	'sort' => array('defaultOrder' => 'name')
));

Do We Even Need Cookies?

A new law came into force on May 26th 2011 in the UK and Europe that affect websites and how they deal with the user flow of saving cookies to a visitors browser.

Previously websites could use cookies as much as they liked and we only limited by the browsers of the people visiting their websites, but as of late May the Privacy and Electronic Communications (EC Directive) Amendment Regulations 2011 require that certain information must be given to that site’s visitors and the user must give his or her consent to the placing of the cookies.

In english, that means that a site must ask all users permission before saving a cookie to their browser.

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