CodeIgniter update page - Simple CRUD website assistance required - codeigniter

Question

After looking through the forums and starting to try to create a basic CRUD website I am currently struggling to have a page that updates the articles as follows. If someone could kindly tell me where I am going wrong, I will be most greatful. I am getting a 404 error at 'news/input'
model (at news_model.php)
public function update($id, $data)
{
$this->db->where('id', $id);
$this->db->update('news', $data);
}
controller (news.php)
public function update($id){
$data = array(
'title' => $this->input->post('title'),
'slug' => $this->input->post('slug'),
'text' => $this->input->post('text'));
if($this->news_model->exists($id)) {
$this->news_model->update($id, $data);
}
else {
$this->news_model->insert($data);
}
}
html (views/news/input.php)
<h2>Update a news item</h2>
<?php echo validation_errors(); ?>
<?php echo form_open('news/update') ?>
<label for="title">Title</label>
<input type="input" name="title" /><br />
<label for="slug">Slug</label>
<input type="input" name="slug" /><br />
<label for="text">Text</label>
<textarea name="text"></textarea><br />
<input type="submit" name="submit" value="Update an item" />

Answer 1

You get a 404 because your news controller seems to have no method 'input'. Try adding something like this:
public function input(){
// load the form
$this->load->view('/news/input');
}
Note that for updating data you will need to fetch and pass it into the view first, then render the (filled out) form using set_val() and other CI functions.
Currently you're "hardcoding" the HTML form which makes populating and maintaining state (when validation fails) difficult. I suggest you play through the forms tutorial on the CI website.
Edit:
To create a update/insert (upsert) controller change as follows:
Controller:
function upsert($id = false){
$data['id'] = $id; // create a data array so that you can pass the ID into the view.
// you need to differntiate the bevaviour depending on 1st load (insert) or re-load (update):
if(isset($_POST('title'))){ // or any other means by which you can determine if data's been posted. I generally look for the value of my submit buttons
if($id){
$this->news_model->update($id, $this->input->post()); // there's post data AND an id -> it's an update
} else {
$this->news_model->insert($id, $this->input->post()); // there's post data but NO id -> it's an insert
}
} else { // nothing's been posted -> it's an initial load. If the id is set, it's an update, so we need data to populate the form, if not it's an insert and we can pass an empty array (or an array of default values)
if($id){
$data['news'] = $this->news_model->getOne($id); // this should return an array of the news item. You need to iterate through this array in the view and create the appropriate, populated HTML input fields.
} else {
$data['news'] = $this->news_model->getDefaults(); // ( or just array();) no id -> it's an insert
}
}
$this->load->view('/news/input',$data);
}
And amend the $id to the action-url in your view:
<?php echo form_open('news/upsert/'.$id) ?>