Zip Encoding Class
******************

CodeIgniter’s Zip Encoding Class permits you to create Zip archives.
Archives can be downloaded to your desktop or saved to a directory.

* Using the Zip Encoding Class

  * Initializing the Class

  * Usage Example

* Class Reference


Using the Zip Encoding Class
============================


Initializing the Class
----------------------

Like most other classes in CodeIgniter, the Zip class is initialized
in your controller using the $this->load->library function:

   $this->load->library('zip');

Once loaded, the Zip library object will be available using:

   $this->zip


Usage Example
-------------

This example demonstrates how to compress a file, save it to a folder
on your server, and download it to your desktop.

   $name = 'mydata1.txt';
   $data = 'A Data String!';

   $this->zip->add_data($name, $data);

   // Write the zip file to a folder on your server. Name it "my_backup.zip"
   $this->zip->archive('/path/to/directory/my_backup.zip');

   // Download the file to your desktop. Name it "my_backup.zip"
   $this->zip->download('my_backup.zip');


Class Reference
===============

class CI_Zip

   $compression_level = 2

      The compression level to use.

      It can range from 0 to 9, with 9 being the highest and 0
      effectively disabling compression:

         $this->zip->compression_level = 0;

   add_data($filepath[, $data = NULL])

      Parameters:
         * **$filepath** ("mixed") – A single file path or an array of
           file => data pairs

         * **$data** ("array") – File contents (ignored if $filepath
           is an array)

      Return type:
         "void"

      Adds data to the Zip archive. Can work both in single and
      multiple files mode.

      When adding a single file, the first parameter must contain the
      name you would like given to the file and the second must
      contain the file contents:

         $name = 'mydata1.txt';
         $data = 'A Data String!';
         $this->zip->add_data($name, $data);

         $name = 'mydata2.txt';
         $data = 'Another Data String!';
         $this->zip->add_data($name, $data);

      When adding multiple files, the first parameter must contain
      *file => contents* pairs and the second parameter is ignored:

         $data = array(
                 'mydata1.txt' => 'A Data String!',
                 'mydata2.txt' => 'Another Data String!'
         );

         $this->zip->add_data($data);

      If you would like your compressed data organized into sub-
      directories, simply include the path as part of the filename(s):

         $name = 'personal/my_bio.txt';
         $data = 'I was born in an elevator...';

         $this->zip->add_data($name, $data);

      The above example will place my_bio.txt inside a folder called
      personal.

   add_dir($directory)

      Parameters:
         * **$directory** ("mixed") – Directory name string or an
           array of multiple directories

      Return type:
         "void"

      Permits you to add a directory. Usually this method is
      unnecessary since you can place your data into directories when
      using "$this->zip->add_data()", but if you would like to create
      an empty directory you can do so:

         $this->zip->add_dir('myfolder'); // Creates a directory called "myfolder"

   read_file($path[, $archive_filepath = FALSE])

      Parameters:
         * **$path** ("string") – Path to file

         * **$archive_filepath** ("mixed") – New file name/path
           (string) or (boolean) whether to maintain the original
           filepath

      Returns:
         TRUE on success, FALSE on failure

      Return type:
         "bool"

      Permits you to compress a file that already exists somewhere on
      your server. Supply a file path and the zip class will read it
      and add it to the archive:

         $path = '/path/to/photo.jpg';

         $this->zip->read_file($path);

         // Download the file to your desktop. Name it "my_backup.zip"
         $this->zip->download('my_backup.zip');

      If you would like the Zip archive to maintain the directory
      structure of the file in it, pass TRUE (boolean) in the second
      parameter. Example:

         $path = '/path/to/photo.jpg';

         $this->zip->read_file($path, TRUE);

         // Download the file to your desktop. Name it "my_backup.zip"
         $this->zip->download('my_backup.zip');

      In the above example, photo.jpg will be placed into the
      *path/to/* directory.

      You can also specify a new name (path included) for the added
      file on the fly:

         $path = '/path/to/photo.jpg';
         $new_path = '/new/path/some_photo.jpg';

         $this->zip->read_file($path, $new_path);

         // Download ZIP archive containing /new/path/some_photo.jpg
         $this->zip->download('my_archive.zip');

   read_dir($path[, $preserve_filepath = TRUE[, $root_path = NULL]])

      Parameters:
         * **$path** ("string") – Path to directory

         * **$preserve_filepath** ("bool") – Whether to maintain the
           original path

         * **$root_path** ("string") – Part of the path to exclude
           from the archive directory

      Returns:
         TRUE on success, FALSE on failure

      Return type:
         "bool"

      Permits you to compress a directory (and its contents) that
      already exists somewhere on your server. Supply a path to the
      directory and the zip class will recursively read and recreate
      it as a Zip archive. All files contained within the supplied
      path will be encoded, as will any sub-directories contained
      within it. Example:

         $path = '/path/to/your/directory/';

         $this->zip->read_dir($path);

         // Download the file to your desktop. Name it "my_backup.zip"
         $this->zip->download('my_backup.zip');

      By default the Zip archive will place all directories listed in
      the first parameter inside the zip. If you want the tree
      preceding the target directory to be ignored, you can pass FALSE
      (boolean) in the second parameter. Example:

         $path = '/path/to/your/directory/';

         $this->zip->read_dir($path, FALSE);

      This will create a ZIP with a directory named “directory”
      inside, then all sub-directories stored correctly inside that,
      but will not include the */path/to/your* part of the path.

   archive($filepath)

      Parameters:
         * **$filepath** ("string") – Path to target zip archive

      Returns:
         TRUE on success, FALSE on failure

      Return type:
         "bool"

      Writes the Zip-encoded file to a directory on your server.
      Submit a valid server path ending in the file name. Make sure
      the directory is writable (755 is usually OK). Example:

         $this->zip->archive('/path/to/folder/myarchive.zip'); // Creates a file named myarchive.zip

   download($filename = 'backup.zip')

      Parameters:
         * **$filename** ("string") – Archive file name

      Return type:
         "void"

      Causes the Zip file to be downloaded from your server. You must
      pass the name you would like the zip file called. Example:

         $this->zip->download('latest_stuff.zip'); // File will be named "latest_stuff.zip"

      Note:

        Do not display any data in the controller in which you call
        this method since it sends various server headers that cause
        the download to happen and the file to be treated as binary.

   get_zip()

      Returns:
         Zip file content

      Return type:
         "string"

      Returns the Zip-compressed file data. Generally you will not
      need this method unless you want to do something unique with the
      data. Example:

         $name = 'my_bio.txt';
         $data = 'I was born in an elevator...';

         $this->zip->add_data($name, $data);

         $zip_file = $this->zip->get_zip();

   clear_data()

      Return type:
         "void"

      The Zip class caches your zip data so that it doesn’t need to
      recompile the Zip archive for each method you use above. If,
      however, you need to create multiple Zip archives, each with
      different data, you can clear the cache between calls. Example:

         $name = 'my_bio.txt';
         $data = 'I was born in an elevator...';

         $this->zip->add_data($name, $data);
         $zip_file = $this->zip->get_zip();

         $this->zip->clear_data();

         $name = 'photo.jpg';
         $this->zip->read_file("/path/to/photo.jpg"); // Read the file's contents

         $this->zip->download('myphotos.zip');
