If you are developing a form for the user, you must write the form validation code to allow only the valid data to be stored in the database. In this topic, we will create a simple registration form in CodeIgniter 3 as an example. Our main purpose is to know how you can validate the form in CodeIgniter 3. Form validation will be performed after the form is submitted and before data is inserted into the database table.
How to do form validation in CodeIgniter 3
Development Steps
Step 1 - Create a MySQL table for the candidate details
Step 2 - Create the view for registration form (register.php)
Step 3 - Write Controller with validation rules (CandidateController.php)
Step 4 - The Model (ModelCandidate.php)
Step 5 - Change setup files and Test the Application
Step 1 - Create a MySQL table for candidate details
Let us create the table named 'candidates' in MySQL database. Table structures is given below:
Table: candidates
This table stores details of all registered candidates.
Below are the columns in this table.
- candidate_id - It is the primary key and auto incremented id of the candidate
- name - Name of the candidate
- address - Address of the candidate
- email_id - Email Id of the candidate
- age - Age of the candidate
candidates.sql
CREATE TABLE `candidates` (
`candidate_id` int(11) NOT NULL,
`name` varchar(100) NOT NULL,
`address` varchar(200) NOT NULL,
`email_id` varchar(100) NOT NULL,
`age` smallint(6) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
ALTER TABLE `candidates`
ADD PRIMARY KEY (`candidate_id`);
ALTER TABLE `candidates`
MODIFY `candidate_id` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=1;
After you create the table, verify if table structure is same as above.
Step 2 - Create the view for registration form (register.php)
It is a simple registration form with input fields name, address, email id and age. There will be validation for each field. For age we will be using a range (18-40) so that we can show how this type of validation can be done in CodeIgniter 3. Let us see the form below:
application/views/register.php
<!DOCTYPE html>
<html lang="en">
<head>
<title>Candidate Registration</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<link rel="stylesheet" href="<?php echo base_url('assets/css/style.css') ?>">
</head>
<body>
<div class="container">
<h4>Candidate Registration</h4>
<p class="error "><?php if ($err_msg != "") { echo $err_msg;}?></p>
<p class="success"><?php if ($succ_msg !="") {echo $succ_msg;}?></p>
<form id ="frm" action = "<?php echo base_url()?>register" method = "post">
<div class="form-group col-md-12">
<label>Name</label>
<input type = "text" name="name" id = "name" class="form-control" value="<?php echo set_value('name');?>" maxlength="100" placeholder="Enter Your Name">
<div class="error"><?php echo form_error('name'); ?></div>
</div>
<div class="form-group col-md-12">
<label>Address</label>
<textarea name="addr" id = "addr" class="form-control" maxlength="200" placeholder="Enter Your Address" ><?php echo set_value('addr');?></textarea>
<div class="error"><?php echo form_error('addr'); ?></div>
</div>
<div class="form-group col-md-12">
<label>Email Id</label>
<input type = "text" name="email" id = "email" class="form-control" value="<?php echo set_value('email');?>" maxlength="100" placeholder="Enter Your Email">
<div class="error"><?php echo form_error('email'); ?></div>
</div>
<div class="form-group col-md-12">
<label>Age <small>(Must be between 18 and 40 only)</small></label>
<input type = "number" name="age" id = "age" class="form-control" value="<?php echo set_value('age');?>" placeholder="Enter Your Age in Years">
<div class="error"><?php echo form_error('age'); ?></div>
</div>
<div class="col-md-12 text-center">
<input type ="submit" name="submit" class="btn btn-primary" value="Submit">
</div>
</form>
</div>
</body>
</html>
It is just a form with few input fields and a submit button. Note that for each input field set_value() will repopulate the value in case of validation error for the field . Also, for each input field, validation error message is displayed using form_error().
Step 3 - Write Controller with validation rules (CandidateController.php)
Our controller will have an index() method to display the form and a register() method to process the submitted form. register() method is the one where form validation will take place. We will have an additional method which is for the age validation callback function. Let's see the code below for the controller class.
application/controllers/CandidateController.php
<?php
defined('BASEPATH') OR exit('No direct script access allowed');
class CandidateController extends CI_Controller {
/**
* Index Page for this controller.
*
* Maps to the following URL
* http://example.com/index.php/welcome
* - or -
* http://example.com/index.php/welcome/index
* - or -
* Since this controller is set as the default controller in
* config/routes.php, it's displayed at http://example.com/
*
* So any other public methods not prefixed with an underscore will
* map to /index.php/welcome/
* @see https://codeigniter.com/user_guide/general/urls.html
*/
function __construct() {
parent::__construct();
$this->load->model('ModelCandidate');
}
public function index(){
$element = [];
$element['succ_msg'] = "";
$element['err_msg'] = "";
$this->load->view('register',$element);
}
public function register(){
$element = [];
$element['succ_msg'] = "";
$element['err_msg'] = "";
// validate each field
$this->form_validation->set_rules('name', 'Name', 'trim|required',
array(
'required'=>'You must provide a %s')
);
$this->form_validation->set_rules('addr', 'Address', 'trim|required',
array(
'required'=>'You must provide an %s')
);
$this->form_validation->set_rules('email', 'Email Id', 'trim|required|valid_email|is_unique[candidates.email_id]',
array(
'required'=>'You must provide an %s',
'valid_email' => 'This is not a valid email address',
'is_unique' => 'This %s already exists')
);
$this->form_validation->set_rules('age', 'Age', 'trim|required|callback_age_check',
array(
'required' => 'You must provide %s')
);
if ($this->form_validation->run() == FALSE) {
// validation not passed, so load the form again
$this->load->view('register',$element);
}
else {
// validation is success, so go for registration
// get the values of form fields
$name = $this->input->post('name');
$addr = $this->input->post('addr');
$email = $this->input->post('email');
$age = $this->input->post('age');
$data = array('name'=>$name, 'address'=>$addr, 'email_id'=>$email, 'age'=>$age);
$result = $this->ModelCandidate->register($data);
if ($result){
$element['succ_msg'] = "Registration successful";
}
else{
$element['err_msg'] = "Error in Registration";
}
$this->load->view('register',$element);
}
} // end of register method
public function age_check($age){
if (!empty($age)){
if ($age <18 || $age >40) {
$this->form_validation->set_message('age_check', '{field} must be between 18 and 40');
return false;
}
else
return true;
}
}
} // end of controller class
In the constructor, we are loading the model named 'ModelCandidate'.
Controller Method index()
index() method is executed by default in a controller. In this method, it just loads the view that displays the registration form.
Controller Method register()
This method gets executed after form submission. It writes validation rules for each field. If validation fails for a field, it reloads the view with error message displayed. But if all fields are validated successfully, this method calls a Model method to insert a row in database table.
It uses form_validation->set_rules() method for each field. Validation for the Age field is done using a custom callback method named age_check() which is defined later in the controller. This callback method returns TRUE or FALSE. Let's see the callback method age_check() below:
public function age_check($age){
if (!empty($age)){
if ($age <18 || $age >40) {
$this->form_validation->set_message('age_check', '{field} must be between 18 and 40');
return false;
}
else
return true;
}
}
It takes the value of the field as parameter and checks if the value is less than 18 or greater than 40. If the value is outside this range, it sets a message and returns FALSE. Otherwise, it returns TRUE.
Step 4 - The Model (ModelCandidate.php)
In the model, register() method takes the input array and uses $db->insert() to insert a row in the databasse table. Below is the model code:
application/models/ModelCandidate.php
class ModelCandidate extends CI_Model {
function __construct() {
parent::__construct();
}
function register($data = []) {
if (!empty($data)) {
$result = $this->db->insert('candidates', $data);
return $result;
}
}
}
style.css
h4{
text-align: center;
margin-top: 50px;
}
p.success{
text-align: center;
color:green;
font-size: 20px;
}
p.error{
text-align: center;
color:red;
font-size: 20px;
}
.error{
color:red;
min-height: 20px;
font-size: 17px;
}
label{
font-weight: bold;
}
#frm {
margin: 5px auto;
padding-top: 21px;
padding-bottom: 40px;
border: 1px solid #09168d;
border-radius: 7px;
background: #fff;
width: 47%;
}
textarea.form-control{
resize: none !important;
height: 100px !important;
}
We added few simple styles here, you can always add better styles.
Step 5 - Update Configuration files and Test the Application
Let us now update few setup files before we run the application. Project folder name is 'registration' under xampp/htdocs. So, the root directory is xampp/htdocs/registration.
The folder 'assets' is created to keep all stylesheets, JavaScripts and image files.
We will update few files in config folder and also including .htaccess file under the root. See below:
- Update autoload.php (application/config/autoload.php)
We added 'database' and 'form_validation' in autoload libraries.
$autoload['libraries'] = array('database','session','form_validation');Also, 'url' and 'form' are added in helper array.
$autoload['helper'] = array('url','form'); - Update config file (application/config/config.php)
$config['base_url'] = 'http://localhost/registration/';$config['index_page'] = ''; - Update database setup file (application/config/database.php)
$active_group = 'default'; $query_builder = TRUE; $db['default'] = array( 'dsn' => '', 'hostname' => 'localhost', 'username' => 'root', 'password' => '', 'database' => 'demo', 'dbdriver' => 'mysqli', 'dbprefix' => '', 'pconnect' => FALSE, 'db_debug' => (ENVIRONMENT !== 'production'), 'cache_on' => FALSE, 'cachedir' => '', 'char_set' => 'utf8', 'dbcollat' => 'utf8_general_ci', 'swap_pre' => '', 'encrypt' => FALSE, 'compress' => FALSE, 'stricton' => FALSE, 'failover' => array(), 'save_queries' => TRUE ); - Update routes file (application/config/routes.php)
Update
routes.phpfor default controller which is candidate:$route['default_controller'] = 'CandidateController'; $route['register'] = 'CandidateController/register'; $route['404_override'] = ''; $route['translate_uri_dashes'] = FALSE; - Update
.htaccess(hypertext access) file to removeindex.phpfrom the URLRewriteEngine On RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php?/$1 [L]
Test The Application
Open the browser and run localhost/registration. You will see the registration form displayed as below:
You can test the validation and successful registration. Just try to submit incomplete form and see the error messages. Do not forget to test age validation.
When you enter all valid values and submit, registartion should be completed successfully and you can check with the database table if the row is inserted in it.
Our development and testing are done. Hope you could understand all the steps and could test it successfully.
Conclusion
Form validation is a very important part of any project. Hope it was useful for you to validate the form using CodeIgniter.
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