SugarCRM restriction on custom field - sugarcrm

Question

i'm totally new to SugarCRM module development, however i have very good knowledge of PHP, ajax and database programming.
Here is my task:I have been asked to create a restriction on a custom field from the clients module.
There is a custom field called identification number, what i need to do is avoid a new client to be saved into the database based on that field, in other words the client has to be unique. It has to display a pop up window saying "that client already exists"

Answer 1

Copy editviewdefs.php of Accounts to the custom folder and change the custom field definition for id_number to this
array(
'name' => 'id_number',
'displayParams' =>
array (
'field' =>
array (
'onChange' => 'check_is_duplicate(this);',
),
),
),
Create a javascript function check_is_duplicate
function check_is_duplicate(obj) {
// Call a script via Ajax. Pass values for id and id_number with the request.
if (o.responseText > 0) {
alert('duplicate');
document.getElementById('SAVE').disabled = true;
} else {
document.getElementById('SAVE').disabled = false;
}
}
You would have to create the script which would be called via ajax request.
In that script you would have to run a query like -
SELECT COUNT(*) AS count FROM accounts
WHERE deleted = 0 AND id != {$record} AND id_number = {$id_number}
Execute the query and return the count.
Afterwards on saving check for duplicates from server side using the beforeSave logic hook.

Answer 2

You can create a custom duplicate check by the following code:
$dictionary['Account']['duplicate_check']['FilterDuplicateCheck']['filter_template'] = array(
array(
'$and' => array(
array('identification_number' => array('$equals' => '$identification_number')),
),
),
);
Add this code in the file: /custom/Extension/modules/Accounts/Ext/Vardefs/duplicate_check.php.
Then, perform a quick repair/rebuild.
How it works:
When you enter the identification number and press save, SugarCRM will perform a duplicate check. If duplicates are found, SugarCRM will list the duplicates and you can choose to use the duplicate or ignore.