---
title: "Validating Form Data with a Rule"
slug: "validating-form-data"
description: "This document discusses how to validate Form Data with a Rule. This action can be achieved through use of Validation Rules; Validation Rules compare a piece of data to a value, and return a \"True\" or \"False\" outcome, based on that value. "
tags: ["User Experience", "Dynamic Behaviors"]
updated: 2024-08-21T18:00:08Z
published: 2024-08-21T18:00:08Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.decisions.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Validating Form Data with a Rule

## Overview

**Validation Rules** evaluate a value within a Form control and return a True or False outcome depending on whether the value satisfies the rule’s condition(s). If a Validation Rule returns False, the validation breaks and a custom message is displayed on the Form control.

Form validation rules are found under **System > Designers > Catalog > System Defaults > Default Form Validation Rules**. Users can also create their own Validation Rules in Designer Folders.

It is highly recommended not to edit the default rules; please contact **support@decisions.com** if you have any questions.

To learn about Validating Form Data with a Flow, please navigate [here](https://documentation.decisions.com/v9/docs/form-validation-flow).

---

## Example

This example illustrates validations rules on an example Employee Leave Request Form.

The **Email Address** field will only accept valid email addresses. The **Start Date**field will only accept today or a future date while the **End Date** field will only accept dates occurring after today.

1. In a Designer Folder, create a Flow and open it in the Flow Designer.
2. After the **Done**outcome path of the **Start**step, add a **Show Form** step from the **Favorite Steps**category. [Create a new Form.](/v9/docs/create-forms)
3. Add the following controls to the Form: one **Button** (Submit), three **Labels** (Email Address, Start Date, End Date), one **Text Box** (Email Address Text Box), and two **Date Time Pickers** (Start Date Picker, End Date Picker).  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-07_14h49_00.png)
4. Under**Properties >****Form Rules > Legacy,**select ADD next to Validation Rules to create a new validation rule.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-07_14h50_28.png)
5. In the **Add Validation Rules**dialog window, name the Rule then select PICK OR CREATE RULE and select the existing preset rule **Is Valid Email.**Confirm with PICK.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h36_25.png)
6. Back in the Add Validation Rules dialog, under **Rule Inputs**select UPDATE INPUTS to automatically update the rule's inputs based off the chosen rule's inputs. Once the 'TextToCheck' input appears, select the pencil icon.
7. In the **Edit Rule Inputs**dialog window, change the **Input Type**to Form Component. For **Form Data Name,**select the data name of the email: 'Employee Email'. Keep the **RunOnValueChanged** checkbox to True.  
  
Select OK to confirm.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h43_13.png)
8. Back in the Add Validation Rules dialog, under **Rule Data > Validation Break Text Box**, enter the message displayed if the rule is broken.
9. In the **Apply To Controls** list, select the checkbox next to the form control that the rule will be applied to, "Email Text Box".
10. Select OK to save the changes and close this dialog.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h44_07.png)
11. Repeat step 5 to return to the Add Validation Rules window to create two new validations rules. These will check for valid state and end dates respectively.
12. For the first Start Date validation, give it a relevant name. For the Rule, select the preexisting **Date Today or After**Rule.
13. Select UPDATE INPUTS and edit the 'dateValue' input. Change Input Type to Form Component and Form Data Name to **State Date**. Select OK to confirm.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h46_04.png)
14. Under Rule Data, enter the text to appear when the validation error occurs in the Validation Break Text. For **Apply To Controls**, select the Start Date [DateTimePicker].
15. To have this **Validation Rule** run at start-up, navigate to **Rule Execution**and set the checkbox next to **Run Rule On Form Show**. Select OK to save and close.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h47_21.png)
16. In the second new End Date validation rule, give it a name and choose **Date After Today** as the **Rule**.
17. Update the Inputs and configure to the correct **Form Component:** "End Date Picker". For Apply to Controls, select the **End Date [DateTimePicker].**
18. Give the Validation a break text that will display if this error occurs.
19. Navigate to **Rule Execution**select the checkbox next to **Run Rule On Form Show**to have this rule run on startup like the Start Date validation. Select OK to save and close.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h49_50.png)

### Debug

1. Save and close the Form Designer. In the Flow Designer, be sure all outcome paths are connected. Select **Debug** in the top action panel.
2. When the Form displays the Start Date Picker and End Date Picker automatically show the validation error. When invalid dates are entered, the validation rules check the dates, and the error message displays.
3. Enter an email address in an invalid format, and the error message appears.
4. When valid information is entered, the rules return true, and users can select Submit.

---

## Validation Rule on a File Upload Control

1. Add a "Doctors Note (If Applicable)" Label and a File Upload button to the Form.
2. In the Form's Properties, navigate to**Properties >****Form Rules > Legacy**and****select ADD next to Validation Rules to create a new validation rule.
3. In the **Add Validation Rules**window, give the rule a name the rule and select PICK OR CREATE RULE to create a new Rule. After naming the Rule, it will open in the Rule Designer.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h51_34.png)
4. Select SETUP INPUT DATA and create a field with **FileData**data type.
5. Configure the Validation Rule with the following logic: **If File.FileName String Ends with Any in List [endsWith] .doc, .docx, .pdf [caseInsensitive] False.**Save and close the Rule Designer.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h53_12.png)
6. Back in the **Add****Validation Rules** dialog, under **Rule Inputs** select **Update Inputs**. Select **Edit** [pencil shaped icon].
7. Change the **Input Type** drop-down list to **Form Component**then choose the name of the File Upload control's data name for the **Form Data Name.**Select OK.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h55_18.png)
8. Back in the **Add Validation Rules** dialog, under **Rule Data > Validation Break Text**, enter the message displayed if the rule is broken. For **Apply To Controls,** select the File Upload control.
9. Under **Rule Execution > Triggers**, select the File Upload trigger for value change.
10. Select OK to save the changes and close this dialog.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-08-20_13h57_12.png)

### Debug

1. Save and close the Form Designer, select Debug in the top action panel of the Flow Designer.
2. Test the File Upload component to see if the Validation Rule is working properly.

---

For further information on Forms, visit the [Decisions Forum](https://community.decisions.com/categories/Forms).