Catalytic fields support entry validation, which prevents or restricts a user from submitting a form or task when a field has incorrect data. Different field types have different validation methods, for example, you can set a max or min value for an Integer, and Decimal field types, or pattern validation for Text field types.

 

With expression validation, you can now set even more powerful, complex validation rules for your fields. The expression uses a Javascript syntax similar to the Field: Field formulas action, which means you’ll need familiarity with Javascript.

For example, you could write the expression (startsWith("SKU", this), to restrict entries to anything starting with SKU, or it could be more complex, ((startsWith("SKU", this) or (startsWith("#", this)), which restricts entries to anything starting with SKU or #

Expression validation is available on all field types. You can add expression validation by selecting Expression next time you add entry validation. To learn more about entry validation, check the Apply entry validation to fields article.

How to use expression validation

The expression validation is based off of the Javascript library Math.js and has access to all basic Math.js calls. Use this as an object in your expression to create statements, such as this > 5

Here are other things to keep in mind when writing expression:

• Reference the value of the field itself using this. For example, this > 5.
• Reference other field values by their Display name. Fields are referenced in two ways:
  • If the field has spaces, use field["field name with spaces"].
  • If the field has no spaces, use field.fieldnamewithoutspaces For example, this == field["field name"].
• Because this is a validator, you cannot create or assign values using an expression. For example, if you set an expression validation on field 1 to: field["field2"] == "Mango"—you cannot assign a value. The expression must include a this.
• There is no need to use result =, as is common in other languages, as this is just a validator and no result is created.
• Expression validation works dynamically, so you can set up validation on other fields, even if those fields are configured in the same step. In other words, if you have two fields in a web form, you can set up an expression validation so the second field is dependent on the first, such as this > field.field1.

Expression validation has built in hinting, and syntax highlighting. As you begin typing, suggested calls or elements appear as options in a drop down. At this time, your expressions are not validated for accuracy, so if you’re encountering an issue, double check the syntax.

Custom Catalytic functions

In addition to the basic Math.js calls, you can use custom catalytic functions in your expressions.

Basic patterns

Math.js is a popular Javascript library, so there are many examples that are useful as references, but Math.js and Javascript are complicated languages and there may be unpredictable outcomes when making changes. You can see some common examples of Math.js in action on the Math.js Examples page.

Always test a pattern before using it live, there may be certain entries that unintentionally pass the validation. You can test validation from the configure field page by entering in a default value.

How to add entry validation to a field

You can add entry validation from the configure field page, such as an Instance Field or form field. Expression validation works for any field type.

1. From the Workflow Builder page, click open the Triggers and Fields section to head to your Instance Fields.

2. Select Add a Field. Scroll to the middle and look for Entry Validation.

   

3. Select Add a Validation under the Entry Validation section.
4. Select the entry validation type from the drop down list, then enter the value.
5. Optionally add an error message under the Error Message section.

Here’s an example of the process for a text field:

 

To learn more about testing validation, adding other types of validation, or how to test validation, check the full Apply entry validation to fields article.

Get help with a problem or question

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