Custom Validators are very easy to create for specific requirements, for example an organisation may have a specific need for creating rules that ensure proper formating of serial numbers, product codes, or bar code conventions. 

A developer can create a new validator and add this to the OpenLinks Validator Library and then reference this Custom Validator in the Open Links Service Configuration File, an example is shown of a validator below.

package webdirector.validation.rules;

import java.util.HashMap;

import webdirector.validation.Rule;

public class EmailRule implements Rule {

   String fieldName;
   HashMap<String, String> errorMsgs = new HashMap();

   public EmailRule( String fieldName ) {
      this.fieldName = fieldName;
      errorMsgs.put( fieldName, "Not a valid email" );
   }

   public boolean checkRule( HashMap<String, String> formResults ) {
      String input = formResults.get( fieldName );
      if ( input == null || input.equals( "" ) || input.matches( "^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}$" ) )
         return true;

      return false;
   }

   public HashMap<String, String> getErrorMessages() {
      return errorMsgs;
   }

   public boolean checkRule( String value ) {
      HashMap<String, String> result = new HashMap<String, String>();
      result.put( fieldName, value );
      return checkRule( result );
   }

   public String getErrorMessage() {
      HashMap<String, String> errors = getErrorMessages();
      return errors.get( fieldName );
   }
}