Upload images using the CodeIgniter class library

CodeIgniter's file upload class allows files to be uploaded. You can specify the file type to be uploaded and the file size to be specified.

The general process of uploading files:

• A form used to upload a file. You can select a file and upload it.
• When this form is submitted, the file is uploaded to the specified directory.
• At the same time, the file will be verified to meet your set requirements.
• Once the file is uploaded successfully, a confirmation window is returned.

The following is a form:

<Form method = "post" action = "<? = Base_url ()?> Admin/img_upload/"enctype =" multipart/form-data "/> <div style =" margin: 0 0 0.5em 0em; "> <input type =" file "name =" userfile "size =" 20 "class =" button "/> <input type =" submit "value =" Upload "class = "button"/> </div> </form>

Next is the upload class:

public function img_upload(){$this->load->helper('url');$config['upload_path'] = './images/'.date('Ym', time()).'/';$config['allowed_types'] = 'gif|jpg|png';$config['file_name'] = date('Y_m_d', time()).'_'.sprintf('%02d', rand(0,99));$config['max_size'] = '500';$config['max_width']  = '1024';$config['max_height']  = '768';$this->load->library('upload', $config);if ( !$this->upload->do_upload())  {   $error = array('error' => $this->upload->display_errors());  } else  {   $data = array('upload_data' => $this->upload->data());  }}

Preference Parameters

Preference settings	Default Value	Option	Description
Upload_path	None	None	File Upload path. The path must be writable. The relative path and absolute path can both be used.
Allowed_types	None	None	The MIME type of the file to be uploaded. Generally, the file extension can be used as the MIME type. Multiple types can be separated by vertical bars (| ).
File_name	None	File name to be used	If this parameter is set, CodeIgniter will rename the uploaded file based on the file name set here. The file name extension must also be of the allowed file type.
Overwrite	FALSE	TRUE/FALSE (boolean)	Overwrite or not. If this parameter is set to TRUE, the original file will be overwritten if the file is uploaded with a duplicate name. If this parameter is set to FALSE, CI will add a number after the file name of the new file. 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	Maximum size of the file to be uploaded (in K ). If this parameter is set to 0, no restriction is imposed. Note: PHP also has this restriction, which can be specified in the php. ini file. The default value is 2 MB.
Max_width	0	None	The maximum width (in pixels) of the uploaded file ). 0 is unlimited.
Max_height	0	None	The maximum height (in pixels) of the uploaded file ). 0 is unlimited.
Max_filename	0	None	The maximum length of a file name. 0 is unlimited.
Encrypt_name	FALSE	TRUE/FALSE (boolean)	Whether to rename the file. If this parameter is set to TRUE, the uploaded file is renamed as a random encrypted string. It is useful when you want the File Uploader not to distinguish the file name uploaded by himself. This option takes effect only when overwrite is FALSE.
Remove_spaces	TRUE	TRUE/FALSE (boolean)	If the parameter is TRUE, the space in the file name is replaced with an underscore. Recommended.

Several functions used

• $ This-> upload-> do_upload (): Configure parameters according to your preference to perform the operation. Note: by default, the uploaded file is namedUserfileAnd the form must be of the "multipart" type.
• $ This-> upload-> display_errors (): IfDo_upload ()An error is returned. This function does not automatically output but returns data, so you can arrange it as required.
• $ This-> upload-> data (): this is an auxiliary function that returns an array of all relevant information about the uploaded file.