Unique content field validation

This module allows you to require that the content supplied for entity fields, node titles or taxonomy terms names will be unique if so configured in each field or title/name of the entity, allowing the administrator to set a validation message in case the filled-in value already exists.

Installation and configuration

Install the module like any other module depending on your project setup via admin UI, via Drush or via Composer.

• Once the module is enabled, you will see a settings group in each content-type / vocabulary called "Unique". Enable the settings by checking the checkbox "Unique" and setting a validation message if you want to. This restricts the entity title/name within that bundle.
• In each field attached to some entity you can also find a settings group called "Unique". Enable the settings by checking the checkbox "Unique" and setting a validation message if you want to. This restricts the field value within that entity allowing unique values.

Supported field types: email, link, decimal, float, integer, list_float, list_integer, entity_reference, list_string, text, text_long, text_with_summary, string, string_long, webform

There is another option if you configure a field to be of multiple cardinality, with this feature, you can prevent the same value from being entered more than once within the same field and configure an error message as well if you want to.