{"id":904,"date":"2013-02-22T22:47:56","date_gmt":"2013-02-23T03:47:56","guid":{"rendered":"http:\/\/cfdbplugin.com\/?page_id=904"},"modified":"2016-01-27T16:47:06","modified_gmt":"2016-01-27T21:47:06","slug":"preventing-duplicate-submissions-from-cf7","status":"publish","type":"page","link":"https:\/\/cfdbplugin.com\/?page_id=904","title":{"rendered":"Preventing Duplicate Submissions from CF7"},"content":{"rendered":"

Situation<\/strong>: You have users who submit forms but you don’t want them to submit more than once.<\/p>\n

Solution<\/strong>: add a custom validation to a form field that uniquely identifies the submission.<\/p>\n

This solution is for Contact Form 7. Contact Form 7 has a hook into which you can inject custom validation code. It is somewhat limited, so read carefully. (This solution is based on: Contact Form 7 Custom Validation<\/a>)<\/p>\n

Let’s assume that essentially what you need to do is to prevent users from submitting a form more than once with the same email address in it. In this example, we will put a validation on one particular form field and check if that email was submitted previously. We will ignore all other fields in this example.<\/p>\n

The limitation to the\u00a0Contact Form 7 field validation is that although we can put in code to validate a particular field, in that code we can’t know what form the submission is coming from. This means that if you set up a validation on a field named “email” then that validation will be run against all form submissions that have an “email” field. If you have more than one form with a field named “email” but you\u00a0only want this validation run for one particular form, then you have a problem.<\/p>\n

The best idea is to give a unique name to the email field in your form. Use this name only on this form and none other. In this example, we use “email_123”. The Contact Form 7 form definition for this example is:
\nForm Name: email_form<\/strong><\/p>\n

\r\n
Your Name (required)
\r\n    [text* name] <\/p>\r\n\r\n
Your Email (required)
\r\n    [email* email_123] <\/p>\r\n\r\n
[submit \"Send\"]<\/p><\/pre>\n
To create the validation, we add WordPress filter code into Tools<\/strong> -> Shortcodes Actions and Filters<\/strong> using the Shortcodes Actions and Filters<\/a> plugin. This is the same technique used in Changing Form Data Before it is Saved<\/a>.<\/p>\n
The following code is an example. You will need to make some changes to make it work for you. In the my_validate_email function<\/strong>:<\/p>\n