User Exists validation
Checks to see if the element's value already exists as a user name in the Joomla user table.
- Error message - The message to display next to the element if the validation fails. This text should explain why the validation failed and what steps the user should take to remedy the error.
- Condition - A PHP expression which if returns false, means that the validation is not run. See here for more information.
- Fail validation when username-
- exists - The validation will fail if the username already exists in the database.
- does not exist - The validation will fail if the username does not exist in the database.
- User element - OPTIONAL (but strongly recommended)- if specified, this should be a user element on your form, which this plugin will then use when editing existing data, to determine if an existing row in the J! users table 'belongs' to this user. If not specified, plugin will use logged on userid, so will fail if (say) an admin is editing someone else's row.