Question

Here’s my problem: I have an html template with a checkbox. When the php script runs, it passes a value to the checkbox’s “checked” property like this:

<input type="checkbox" name="form_data[show_products]" {SHOW_PRODUCTS} />

where {SHOW_PRODUCTS} can be either 'checked="true"' or '', depending on whether the data in the database column is 1 or 0. So, in other words, the checkbox is checked, or unchecked, in accordance with the data passed from the database.

Now, since this is the template for the edit form, I need to gather the value of the “checked” property and pass it to the database. However, if I uncheck the checkbox that has been checked automatically at page load and try to save changes, the script still writes 1 to the database instead of 0. How can I change this?

EDIT

These are the php parts that handle the data:

else if (isset($_POST['edit']))
{   
    $form_data = $_POST['form_data'];
    $present_id = $form_data['present_id']; 
    $present=new Present();
    $present->load($present_id); 

    if (isValidForm())
        {       
        $present->set($form_data);
        $present->update();
        }
    else
        {
        $errors=$formValidator->getErrors();
        $page_content_HTML=edit_form_HTML($form_data, $errors);
        }
}

function set($data){
    $keys=array_keys($data);
    foreach($keys as $key)
    {
        $this->$key=$data[$key];
    }   
}

function update(){
        global $db;
        $date_from = format_datetime($this->date_from, "%Y.%m.%d. %H:%M:%S");
        $date_to = format_datetime($this->date_to, "%Y.%m.%d. %H:%M:%S");
        $sql="UPDATE presents SET present_name='".$this->present_name."', description='".$this->description."', present_image='".$this->present_image."', date_from='".$date_from."', date_to='".$date_to."', short_description='".$this->short_description."', show_products='".$this->show_products."' WHERE present_id='$this->present_id'";
        $db->query($sql);

}

Answer 1

The problem is not the form / checkbox but how you handle the request data in your PHP script. As I commented before: An unchecked checkbox is not part of the POST or GET request (it’s not just empty but it’s not existent).

Therefore, $this->show_products does not exist when the box is unchecked.

Try following: Add the line

$present->show_products = 0;

right before

$present->set($form_data);

This makes show_products default to “off” (“0”) and it only gets overwritten if the checkbox is checked.

(Btw: I also think, if the CB is checked that the value will be “on” an not “1”. Add the attribute value="1" to the checkbox tag to make it “1” instead).