How do you handle file validation in FuelPHP?

Handling file validation in FuelPHP involves using the Validation class to ensure that uploaded files meet specific criteria, such as size, type, and required fields. Here’s a brief overview of how you can perform file validation in FuelPHP:

1. Basic File Validation

Use the Validation class to define and apply validation rules to files. Here’s how you can validate file uploads in a controller:

Example Controller:

Example


<?php

class Controller_Upload extends Controller
{
    public function action_upload()
    {
        // Check if a file is uploaded
        if (Input::file('file_upload'))
        {
            // Create a validation instance
            $val = Validation::forge();
            
            // Add file validation rules
            $val->add_field('file_upload', 'File Upload', 'required|file_type[jpg,png]|max_size[5M]');
            
            // Run the validation
            $val->run(array('file_upload' => Input::file('file_upload')));

            if ($val->validated())
            {
                // Proceed with file handling
                $file = Input::file('file_upload');
                $destination = APPPATH . 'uploads/';
                $filename = $file['name'];
                
                if (Upload::save($file, $filename, $destination))
                {
                    return Response::forge('File uploaded and validated successfully');
                }
                else
                {
                    return Response::forge('Failed to upload file', 500);
                }
            }
            else
            {
                // Validation failed
                $errors = $val->error();
                return Response::forge('File validation failed: ' . implode(', ', $errors), 400);
            }
        }
        else
        {
            return Response::forge('No file uploaded', 400);
        }
    }
}

Validation Rules

required: Ensures that a file is uploaded.
file_type: Validates that the file type matches the specified types (e.g., jpg, png).
max_size: Validates the maximum file size (e.g., 5M for 5 megabytes).

3. Additional Validation Methods

You can extend validation with additional rules or custom validation logic if needed:

Custom Validation: Create custom validation rules for more complex scenarios.
Error Handling: Retrieve and display validation errors to the user.

Summary

Use Validation::forge(): Create a validation instance.
Define Validation Rules: Add rules like required, file_type, and max_size.
Run Validation: Validate the uploaded file and handle errors accordingly.