PHP form validation is most important any HTML form, because if your form is not validated then the user can do anything with your form. they can submit an empty form, so each company has different requirements and each company can set validations according to has requirements. so you can examine how PHP form validation is important.
PHP Form Validation rules
In this article we will cover these validation rules:
- Required rule
- uniqueEmail rule
- min_len rule
PHP Form Validation Source Code
index.php
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<?php include "db.php"; include "validation.php"; $validation = new validation; if(isset($_POST['btn'])){ $validation->validate('fullName', 'full name', 'required'); $validation->validate('email', 'Email', 'uniqueEmail|users|required'); $validation->validate('password', 'Password', 'required|min_len|6'); if($validation->run()){ echo "Form is sumitted"; } } ?> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Form valiations</title> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous"> </head> <body> <div class="container mt-5"> <div class="row"> <div class="col-md-5"> <h3>Create new account</h3><hr> <form action="" method="POST"> <div class="form-group"> <input type="text" name="fullName" class="form-control" placeholder="Enter fullname" value="<?php if($validation->input('fullName')): echo $validation->input('fullName'); endif; ?>"> <div class="error text-danger"> <?php if(!empty($validation->errors['fullName'])): echo $validation->errors['fullName']; endif; ?> </div> </div> <div class="form-group"> <input type="email" name="email" class="form-control" placeholder="Enter email" value="<?php if($validation->input('email')): echo $validation->input('email'); endif; ?>"> <div class="error text-danger"> <?php if(!empty($validation->errors['email'])): echo $validation->errors['email']; endif; ?> </div> </div> <div class="form-group"> <input type="password" name="password" class="form-control" placeholder="Create a new password" value="<?php if($validation->input('password')): echo $validation->input('password'); endif; ?>"> <div class="error text-danger"> <?php if(!empty($validation->errors['password'])): echo $validation->errors['password']; endif; ?> </div> </div> <div class="form-group"> <input type="submit" name="btn" class="btn btn-info" value="Save"> </div> </form> </div> </div> </div> </body> </html> |
db.php
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<?php class db { public $connect; public function __construct() { try { $this->connect = new PDO("mysql:host=localhost;dbname=example", 'root', ''); } catch(PDOException $e){ echo "Connection error: ". $e->getMessage(); } } } ?> |
validation.php
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<?php error_reporting(0); class validation extends db { public $errors = []; public function input($field){ if($_SERVER['REQUEST_METHOD'] == 'POST' || $_SERVER['REQUEST_METHOD'] == 'post'){ return strip_tags(trim($_POST[$field])); } else if($_SERVER['REQUEST_METHOD'] == 'GET' || $_SERVER['REQUEST_METHOD'] == 'get'){ return strip_tags(trim($_GET[$field])); } } public function validate($field, $label, $rules){ // Split rule string on pipe sign $allRules = explode("|", $rules); $inputField = $this->input($field); // Check required rule in the array if(in_array("required", $allRules)){ if(empty($inputField)){ return $this->errors[$field] = $label . " is required"; } } // Close required rule // Check uniqueEmail rule in the array if(in_array('uniqueEmail', $allRules)){ $uniqueIndex = array_search("uniqueEmail", $allRules); $tableIndex = $uniqueIndex + 1; $tableName = $allRules[$tableIndex]; $result = $this->connect->prepare(" SELECT * FROM " . $tableName . " WHERE " . $field . " = ? "); if($result->execute([$inputField])){ if($result->rowCount() > 0 ){ return $this->errors[$field] = $label . " is already exist"; } } } // Close uniqueEmail rule // Check min_len rule in the array if(in_array("min_len", $allRules)){ $minLenIndex = array_search("min_len", $allRules); $valueIndex = $minLenIndex + 1; $minValue = $allRules[$valueIndex]; if(strlen($inputField) < $minValue){ return $this->errors[$field] = $label . " is too short"; } } } public function run(){ if(empty($this->errors)){ return true; } else { return false; } } } ?> |
