Ajax and Ajax Frameworks

I have been a developer for nearly 20 years and a web developer for about 10 years. Over the years, I have considered creating a blog to share the things I have learned (and am learning) about web design and development, but I never seemed to have the time. When I began learning about web development using Ajax and Ajax Frameworks, I decided to take the time to create this blog.

My intention for this blog is to focus primarily on Ajax Frameworks, but since web development requires knowledge of many technologies, I will occasionally write about things such as CSS, Javascript, PHP, MySQL, Flash, etc.

Lately, I have been using JQuery as my primary Ajax tool. Although I have used other Ajax Frameworks in the past (Dojo Toolkit, Yahoo! User Interface Library, Scriptaculous/Prototype), JQuery has thus far been the easiest to learn. In my first few posts I will discuss some of the JQuery Plugins that I have created. Some of these include: a plugin for Google Maps (jquery.imGoogleMaps), Form validation and submission (jquery.imValidateForm), Page Populater (jquery.imPagePopulate), and a plugin to create lists (jquery.imList).

While I am still learning about some of the other Ajax Frameworks, I hope that what I have learned will be helpful to others. Just remember, “When you can pull the pebbles from my hand…”

Multi-Purpose CodeIgniter Forms

Saturday, December 5th, 2009

One aspect of CodeIgniter that I don’t like is the amount of view files that I have to create. Although I create folders to group relevant views, I’m always searching through files to find the view that I need. To reduce the amount of files that I need for a project, I usually create a single view file to handle both inserts and updates to a table. But I had to create a CodeIgniter Helper function in order to make it work.

The Model

First I create the model. For brevity, I’m only showing the relevant methods (select, insert and update).

^?View Code PHP

class mTours extends Model {
    	function mTours() {
    		parent::Model();
	}
 
       function getTour($id) {
		$data = array();
		$options = array('tour_id' => $id);
		$Q = $this->db->getwhere('tours', $options, 1);
		if ($Q->num_rows() > 0) {
			$data = $Q->row_array();	
		}	
 
		$Q->free_result();
		return $data;
	}
 
        function addTour(){
		$d = date('Y-m-d H:i:s');
	        $data = array('tour_date' => db_clean($_POST['tour_date'],30),
				  'tour_type' => db_clean($_POST['tour_type'],20),
				  'locations' => $_POST['locations'],
		                  'tour_cost' => db_clean($_POST['tour_cost'],10),
		                  'tour_deposit' => db_clean($_POST['tour_deposit'],10),
				  'tour_includes' => $_POST['tour_includes'],
				  'mod_date' => $d
	         );
 
		$this->db->insert('tours',$data);
	}
 
	function updateTour(){
		$d = date('Y-m-d H:i:s');
	        $data = array('tour_date' => db_clean($_POST['tour_date'],30),
				  'tour_type' => db_clean($_POST['tour_type'],20),
				  'locations' => $_POST['locations'],
		                  'tour_cost' => db_clean($_POST['tour_cost'],10),
		                  'tour_deposit' => db_clean($_POST['tour_deposit'],10),
				  'tour_includes' => $_POST['tour_includes'],
				  'mod_date' => $d
		 );
		$this->db->where('tour_id',id_clean($_POST['id']));
		$this->db->update('tours',$data);	
	}
}

The Helper

Next, I’m going to update a custom CodeIgniter Helper that I created. The helper is used to retrieve table columns from any MySQL database table. I’m updating it so that it will return an array of column names with empty values.

^?View Code PHP

function getTableColumns($tName, $empty=false) {
	$data = array();
	$CI=& get_instance();
	$sql = "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = '$tName'";
	$Q = $CI->db->query($sql);
	if ($Q->num_rows() > 0) {
		foreach ($Q->result_array() as $row){
                       // if $empty is true, return associative array with empty values
                       // else return array containing column names
			if ($empty) {
	         	        $data[$row['COLUMN_NAME']] = '';
			} else {
				$data[] = $row['COLUMN_NAME'];
			} 	
                }
	}	
	$Q->free_result();
	return $data;	
}

I named the helper ‘mysql_table_helper’ and placed it in application/helpers. I am also auto loading the helper so that I don’t have to load it every time I need it (application/config/autoload.php).

The Controller

Next I create a create method and an edit method in my controller. In both of these methods, I create a variable that stores the type of update (create or edit). This variable is sent to the view with the other variables.

^?View Code PHP

function tour_create() {
	if ($this->input->post('tour_date')){
  		$this->mTours->addTour();
  		$this->session->set_flashdata('message','Tour added');
  		redirect('admin/dashboard','refresh');
  	} else {
		$data['title'] = "Add Tour";
		$data['page'] = 'admin/tour_create_edit';
		$data['updType'] = 'create';
                // get the column names from the tours table using the helper
		$data['tour'] = getTableColumns('tours, true);
		$data['navList'] = $this->mainMenu;
		$data['tIncludes'] = $this->mTours->getTourInclude();
		$this->load->vars($data);
		$this->load->view('main');    
	}
}
 
function tour_edit($id=0) {
	if ($this->input->post('tour_date')){
  		$this->mTours->updateTour();
  		$this->session->set_flashdata('message','Tour updated');
  		redirect('admin/dashboard','refresh');
  	} else {
		$data['title'] = "Update Tour";
		$data['page'] = 'admin/tour_create_edit';
		$data['navList'] = $this->mainMenu;
		$data['updType'] = 'edit';
		$data['tour'] = $this->mTours->getTour($id);
		$data['tIncludes'] = $this->mTours->getTourInclude();
		$this->load->vars($data);
		$this->load->view('main');    
	}
}

Both the tour_create and tour_edit methods use the same view file.

^?View Code PHP

$data['page'] = 'admin/tour_create_edit';

There are three primary differences between the tour_create and tour_edit methods:

The tour_create method uses the getTableColumns helper function. The tour_edit method does not need to use the function because it is querying actual data.
The tour_edit method is passed an argument, the value of which is the tour_id. The tour_id is required for the updateTour method in the mTours model.
^?View Code PHP
//mTours - updateTour methodd $this->db->where('tour_id',id_clean($_POST['id']));

The updType variable tells the view which controller method to call.

^?View Code PHP

// tour_create
$data['updType'] = 'create';
// tour_edit
$data['updType'] = 'edit';

The View

Our view, tour_create_edit.php, displays the form and calls the relevant controller method based upon the value of the updType variable.

^?View Code PHP

<?php echo $this->tinyMce;?>
<h3><?php echo $title;?></h3>
 
<?php
// if the updType is equal to 'create', call the <strong>tour_create</strong> method, else call the <strong>tour_edit</strong> method
echo ($updType == 'create') ? form_open('admin/tour_create') : form_open('admin/tour_edit');
echo "<p><label for='tour_date'>Tour Date</label><br/>";
$data = array('name'=>'tour_date','id'=>'tour_date','size'=>20, 'value' => $tour['tour_date']);
echo form_input($data) ."</p>";
 
echo "<p><label for='tour_type'>Tour Type</label><br/>";
$data = array('arrow' => 'arrow', 'sponsored' => 'Sponsored');
echo form_dropdown('tour_type', $data) . "</p>";
 
echo "<p><label for='tour_cost'>Tour Cost</label><br/>";
$data = array('name'=>'tour_cost','id'=>'tour_cost','size'=>10, 'value' => $tour['tour_cost']);
echo form_input($data) ."</p>";
 
echo "<p><label for='tour_deposit'>Tour Deposit</label><br/>";
$data = array('name'=>'tour_deposit','id'=>'tour_deposit','size'=>10, 'value' => $tour['tour_deposit']);
echo form_input($data) ."</p>";
 
echo "<p><label for='locations'>Locations</label><br/>";
$data = array('name'=>'locations','id'=>'locations','rows'=>5, 'cols'=>'40', 'value' => $tour['locations']);
echo form_textarea($data) ."</p>";
 
echo "<p><label for='tour_includes'>Trip Includes</label><br/>";
$data = array('name'=>'tour_includes','id'=>'tour_includes','rows'=>5, 'cols'=>'40', 'value' => $tour['tour_includes']);
echo form_textarea($data) ."</p>";
 
// if updType equals edit, create hidden field that contains the tour_id
if ($updType == 'edit') {
	echo form_hidden('id',$tour['tour_id']);
}
$cap = ($updType == 'create') ? 'add tour' : 'update tour';
echo form_submit('submit',$cap);
echo form_close();
 
echo anchor('admin/dashboard', 'Back To Dashboard');
?>

Note: If I did not use the helper function to create an empty array, the application would receive an error:
A PHP Error was encountered
Severity: Notice
Message: Undefined variable: tour

Note: To view information on using TinyMCE with CodeIgniter see my post: CodeIgniter and TinyMCE.

In the tour_create_edit view, I tell CodeIgniter to create a form action based upon the value of updType.

^?View Code PHP

echo ($updType == 'create') ? form_open('admin/tour_create') : form_open('admin/tour_edit');

The form action calls the relevant controller method. The updateTourmethod in the mTours model requires the tour_id in order to update an existing record. The view passes the tour_id as a hidden field.

^?View Code PHP

if ($updType == 'edit') {
	echo form_hidden('id',$tour['tour_id']);
}

The tour_edit method in the controller calls the getTour method in the mTours model. This data is passed to the view.

^?View Code PHP

$data['tour'] = $this->mTours->getTour($id);

The view can now use this data to display the relevant values for each field in the form. If value does not exist, then nothing is displayed in the field

^?View Code PHP

$data = array('name'=>'tour_date','id'=>'tour_date','size'=>20, <strong>'value' => $tour['tour_date']</strong>);

That’s it. With the use of a simple helper function, I now only need one CodeIgniter view file to insert and update a record.

Categories: Codeigniter
You can follow any responses to this entry through the RSS 2.0 feed.
You can leave a response, or trackback from your own site.

2 Responses to “Multi-Purpose CodeIgniter Forms”

Multi-Purpose CodeIgniter Forms | GrasshopperPebbles.com « Coder Online Says:
December 8th, 2009 at 12:32 am

[...] Link: Multi-Purpose CodeIgniter Forms | GrasshopperPebbles.com [...]
Nathan Says:
April 26th, 2011 at 2:07 pm

Hi,

Stumbled upon this looking for something else but the 5minutes reading has been well rewarded. I will be using this technique – it will make building a CMS a lot easier.

Thanks

Multi-Purpose CodeIgniter Forms

The Model

The Helper

The Controller

The View

2 Responses to “Multi-Purpose CodeIgniter Forms”

Home Business Ads

Categories

Archives

Tags

Comments

Blogroll