How to retain dynamically created input fields values if database fails? - php

Question

I have a big form around 70 input fields and in the form there are buttons that can create additional input fields. My problem is how do I retain these input fields and their values if something on the server goes wrong upon submitting the form, like database insert failure? I have dynamic validation but what if something goes wrong upon submitting?

Answer 1

You have a lot of options.
You could use ajax to post your form, and then redirect to a new page if successful, or alert the user if not (easiest!)
You could recreate the from on the server side from the post variables (harder with a complex form)
The server could send back the form values on failure, and you can write JS to recreate the form (might be easy if you already have JS to manage the form).
You could pass the actual HTML for the form along with the form values, and have the server use it to recreate the form (you may lose JS events depending on how you hook them up, not the best option in general).
There are many more options that are less useful. I would recommend #1.

Answer 2

For a really simple solution:
You can store the values in an object and only once you've got a confirmed DB insert clear it. If insert fails, and you can retry a few times and it and if fails repeatedly, you can write the values to a CSV log file to handle manually.
More complex solution
Queue. Have all insert requests get queue into a job queue using Zend Jobserver, RabbitMQ or Gearman. Then create a worker process to run the inserts on the other end of the queue. This will allow you to re-run /retry failed jobs.

Answer 3

Why so many fields on a single page? I would reconsider doing this. At any rate, if you have server side validation and it fails you can set up the page to have each field use a default value based on the post value that was sent to the server... So just send them back to the same page and have the input fields value set to the post value.
Here is an example.
$username = array(
'name' => 'username',
'id' => 'username',
'maxlength' => '255',
'size' => '28',
'title' => 'username is required.',
'class' => 'form-text required',
'value' => $this->input->post('username'),
);
<?php echo form_input($username); ?>

Answer 4

here are a couple of function that you can use to store the form values in a session:
//save form inputs
function Hold_Form_Input()
{
$FormPost = array();
foreach ($_POST as $key => $entry)
{
$FormPost[''.$key.'']= $entry;
}
$_SESSION['post_form']= $FormPost;
}
//Clear form values upon success
function Clear_Form_Input()
{
if (isset($_SESSION['post_form']))
{
unset($_SESSION['post_form']);
return true;
}
return false;
}
//Reprint form values as needed
function Keep_on_error($fieldname)
{
if(isset($_SESSION['post_form']) && strlen($_SESSION['post_form'][$fieldname]) > 0)
{
$fill = $_SESSION['post_form'][$fieldname];
return $fill;
}
return false;
}