# How To Tutorials

How to Use Extended Class Validation and Display |

Starting with PxPlus 2019, Extended Class Validation allows for additional data validation and the ability to add display-only fields based on a table when designing NOMADS panels. For example, you may have a Customer Maintenance panel with a Salesperson Code field that you want to validate against the Salesperson table. You may also want to display the Salesperson Name, along with other data, when a valid Salesperson Code is entered.

The steps below show you how to accomplish this.

How to Define a Multi-Line Data Class with Extended Validation

1. | In Data Class Definitions maintenance, create a new dynamic Multi-Line data class (i.e. SALESREP).
2. | On the Validation tab, select the Use Extended Validation check box.
3. | In the Table field, select the data table to be used for the validation.
4. | From the Key drop box, select the key to use for the verification. All the keys defined for the table are loaded.
5. | From the Descriptive Field drop box, select the data element (i.e. Salesperson Name) that is to be available when designing the NOMADS panel. All data elements from the table are loaded.
6. | Select the Populate All Fields check box to make all the data elements from the selected table available when designing the NOMADS panel.
7. | (Optional) You can override the standard validation message by selecting a message library in the Error if Invalid field.
8. | (Optional) Program logic can also be entered to override the standard validation message in the Logic if not Found field.
9. | Enter the other required fields and save the Data Class definition.

How to Create NOMADS Multi-Line Controls to Use with Extended Validation and Display

1. | Call up the NOMADS panel.
2. | Create a new Multi-Line control and give it a name (i.e. SALESPERSON). Enter the data class SALESREP that you created earlier (in Step 1 above under Data Class Definition).
3. | Create another new Multi-Line control, which will be used for the Salesperson Name.
4. | To get the data you want, you can use one of the following two methods: Method 1: In the Multi-Line control Name field, enter the name using the syntax SHOW.name.element (i.e. SHOW.SALESPERSON.NAME) where SALESPERSON is the name of the Multi-Line control created in Step 2, and NAME is the name of the data element from the table. OR Method 2: Click the Extended Class Browse button beside the Multi-Line control Name field to display the data elements from the table based on the SALESPERSON Multi-Line control created in Step 2. When a data element is selected, the same control Name syntax used in Method 1 is created.
5. | When creating a SHOW Multi-Line control, the Locked, Borderless and Transparent attributes (on the Attributes tab) are automatically set.
6. | You can continue to create new Multi-Line controls and select other data elements to display as desired.

## See Also

Example: Extended Validation (Multi-Lines)
Example: Extended Validation (Grids)