Clase de Carga de Archivo
La Clase de Carga de Archivo de CodeIgniter le permite subir archivos. Puede establecer varias preferencias, restringir el tipo y tamaño de los archivos.
El Proceso
Subir un archivo involucra el siguiente proceso general:
- Un formulario de carga es mostrado, permitiendole al usuario seleccionar un archivo y subirlo.
- Cuando el formulario es enviado, el archivo es subido a la destinación que especifique.
- En el camino, el archivo es validado para estar seguro que es permitido basado en las preferencias que haya establecido.
- Una vez cargado, al usuario se le mostrará un mensaje de éxito.
Para demostrar este proceso aquí hay un pequeño tutorial. Luego encontrará información de referencia.
Creando el Formulario de Carga
Usando un editor de texto, crear un formulario llamado formulario_carga.php. En él, ubique este código y guardelo en su applications/views/ folder:
Notará que estamos usando el asistente de formulario para crear la etiqueta de apertura de formulario. La carga de archivos requiere un formulario "multipart", así que el asistente crea la sintaxis apropiada para usted. También notará que hay un variable $error. Esto es para que podamos mostrar mensajes de error en el caso que el usuario haga algo mal.
La página de éxito
Usando un editor de texto, debes crear un formulario llamado upload_success.php. En el, coloque este código y guárdelo dentro de su carpeta applications/views/:
El controlador
Usando un editor de texto, debe crear un controlador llamado upload.php. En el, coloque el siguiente código y guárdelo en su carpeta applications/controllers/:
La carpeta Upload
Ud. necesitará una carpeta de destino para sus imágines subidas. Cree una carpeta en la raiz de su instalación CodeIgniter llamado uploads y establezca los permisos de archivo a 777.
Pruébelo!
Para probar su propio formulario, visite su sitio usando una URL similar a esta:
www.tu-sitio.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 CodeIgniter, 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->load->library('upload', $config);
// Alternately you can set preferences by calling the initialize function. Useful if you auto-load the class:
$this->upload->initialize($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. |