Conditional Validation

The data-ctrovalidate-if attribute allows you to define dependencies between fields. Validation for a field only executes when the specified condition on a "controller" field is met.

Technical Syntax

The directive follows the format controllerName:conditionType[=value].

• : separates the controller field name from the condition type
• = (for value type only) separates the condition type from the expected value

1. Boolean State (checked)

Validates the target only when the controller (checkbox or radio) is checked.

<input type="checkbox" name="shipping_separate" id="shipping" />
 
<input
  name="shipping_address"
  data-ctrovalidate-rules="required"
  data-ctrovalidate-if="shipping_separate:checked"
/>

2. Value Comparison (value)

Validates the target only when the controller's current value equals the specified string. Note the = sign between type and value.

<select name="method">
  <option value="none">None</option>
  <option value="express">Express</option>
</select>
 
<input
  name="express_code"
  data-ctrovalidate-rules="required"
  data-ctrovalidate-if="method:value=express"
/>

3. Presence (present)

Validates the target only when the controller has a truthy value. This is the default if no condition type is provided.

<input name="referral_code" />
 
<input
  name="referrer_name"
  data-ctrovalidate-rules="required"
  data-ctrovalidate-if="referral_code"
/>

Equivalent explicit form:

data-ctrovalidate-if="referral_code:present"

Behavior & Lifecycle

• Automatic Cleanup: When the dependency condition is not met, the dependent field is treated as valid. Errors are cleared, CSS classes are removed, and ARIA attributes are reset.
• Dependency Tracking: When realTime is enabled, the controller field's input event triggers re-validation of all its dependents.
• Unmet condition types: If the condition type string is not checked, value, or present, the dependency is treated as unmet (field is skipped).

Next Steps

• Built-in Rules — Apply any of the 22 rules conditionally.
• Dynamic Fields — Managing dependencies for fields added at runtime.
• API Reference — Programmatic dependency management.