File Uploading Class
Code Igniter's File Uploading Class permits files to be uploaded. You can set various preferences, restricting the type and size of the files.
The Process
Uploading a file involves the following general process:
- An upload form is displayed, allowing a user to select a file and upload it.
- When the form is submitted, the file is uploaded to the destination you specify.
- Along the way, the file is validated to make sure it is allowed to be uploaded based on the preferences you set.
- Once uploaded, the user will be shown a success message.
To demonstrate this process here is brief tutorial. Afterward you'll find reference information.
Creating the Upload Form
Using a text editor, create a form called upload_form.php. In it, place this code and save it to your applications/views/ folder:
You'll notice we are using a form helper to create the opening form tag. File uploads require a multipart form, so the helper creates the proper syntax for you. You'll also notice we have an $error variable. This is so we can show error messages in the event the user does something wrong.
The Success Page
Using a text editor, create a form called upload_success.php. In it, place this code and save it to your applications/views/ folder:
The Controller
Using a text editor, create a controller called upload.php. In it, place this code and save it to your applications/controllers/ folder:
The Upload Folder
You'll need a destination folder for your uploaded images. Create a folder at the root of your Code Igniter installation called uploads and set its file permissions to 777.
Try it!
To try your form, visit your site using a URL similar to this one:
www.your-site.com/index.php/upload/
You should see an upload form. Try uploading an image file (either a jpg, gif, or png). If the path in your controller is correct it should work.
Reference Guide
Initializing the Upload Class
Like most other classes in Code Igniter, the Upload class is initialized in your controller using the $this->load->library function:
$this->load->library('upload');
Once the Upload class is loaded, the object will be available using: $this->upload
Setting Preferences
Similar to other libraries, you'll control what is allowed to be upload based on your preferences. In the controller you built above you set the following preferences:
$config['upload_path'] = './uploads/';
$config['allowed_types'] = 'gif|jpg|png';
$config['max_size'] = '100';
$config['max_width'] = '1024';
$config['max_height'] = '768';
$this->upload->initialize($config);
The above preferences should be fairly self-explanatory. Below is a table describing all available preferences.
Preferences
The following preferences are available. The default value indicates what will be used if you do not specify that preference.
| Preference | Default Value | Options | Description |
|---|---|---|---|
| upload_path | None | None | The path to the folder where the upload should be placed. The folder must be writable and the path can be absolute or relative. |
| allowed_types | None | None | The mime types corresponding to the types of files you allow to be uploaded. Usually the file extension can be used as the mime type. Separate multiple types with a pipe. |
| overwrite | FALSE | TRUE/FALSE (boolean) | If set to true, if a file with the same name as the one you are uploading exists, it will be overwritten. If set to false, a number will be appended to the filename if another with the same name exists. |
| max_size | 0 | None | The maximum size (in kilobytes) that the file can be. Set to zero for no limit. Note: Most PHP installations have their own limit, as specified in the php.ini file. Usually 2 MB (or 2048 KB) by default. |
| max_width | 0 | None | The maximum width (in pixels) that the file can be. Set to zero for no limit. |
| max_height | 0 | None | The maximum height (in pixels) that the file can be. Set to zero for no limit. |
| encrypt_name | FALSE | TRUE/FALSE (boolean) | If set to TRUE the file name will be converted to a random encrypted string. This can be useful if you would like the file saved with a name that can not be discerned by the person uploading it. |
| remove_spaces | TRUE | TRUE/FALSE (boolean) | If set to TRUE, any spaces in the file name will be converted to underscores. This is recommended. |
Setting preferences in a config file
If you prefer not to set preferences using the above method, you can instead put them into a config file. Simply create a new file called the upload.php, add the $config array in that file. Then save the file in: config/upload.php and it will be used automatically. You will NOT need to use the $this->upload->initialize function if you save your preferences in a config file.
Function Reference
The following functions are available
$this->upload->do_upload()
Performs the upload based on the preferences you've set. Note: By default the upload routine expects the file to come from a form field called userfile, and the form must be a "multipart type:
<form method="post" action="some_action" enctype="multipart/form-data" />
If you would like to set your own field name simply pass its value to the do_upload function:
$field_name = "some_field_name";
$this->upload->do_upload($field_name)
$this->upload->display_errors()
Retrieves any error messages if the do_upload() function returned false. The function does not echo automatically, it returns the data so you can assign it however you need.
Formatting Errors
By default the above function wraps any errors within <p> tags. You can set your own delimiters like this:
$this->upload->display_errors('<p>', '</p>');
$this->upload->data()
This is a helper function that returns an array containing all of the data related to the file you uploaded. Here is the array prototype:
Array
(
[file_name] => mypic.jpg
[file_type] => image/jpeg
[file_path] => /path/to/your/upload/
[full_path] => /path/to/your/upload/jpg.jpg
[raw_name] => mypic
[orig_name] => mypic.jpg
[file_ext] => .jpg
[file_size] => 22.2
[is_image] => 1
[image_width] => 800
[image_height] => 600
[image_type] => jpeg
[image_size_str] => width="800" height="200"
)
Explanation
Here is an explanation of the above array items.
| Item | Description |
|---|---|
| file_name | The name of the file that was uploaded including the file extension. |
| file_type | The file's Mime type |
| file_path | The absolute server path to the file |
| full_path | The absolute server path including the file name |
| raw_name | The file name without the extension |
| orig_name | The original file name. This is only useful if you use the encrypted name option. |
| file_ext | The file extension with period |
| file_size | The file size in kilobytes |
| is_image | Whether the file is an image or not. 1 = image. 0 = not. |
| image_width | Image width. |
| image_heigth | Image height |
| image_type | Image type. Typically the file extension without the period. |
| image_size_str | A string containing the width and height. Useful to put into an image tag. |