AUR4206

Error Message

AUR4206: Unable to parse binding expression: {{expression}}

Description

This error occurs when the validation controller cannot parse the binding expression used with validation. This typically happens with complex or malformed binding expressions.

Common Scenarios

<!-- ❌ Problem: Complex expressions that can't be parsed -->
<input value.bind="user[getField()] & validate">
<input value.bind="(complex ? expression : here) & validate">

Solution

<!-- ✅ Correct: Simple, parseable expressions -->
<input value.bind="user.name & validate">
<input value.bind="formData.email & validate">

// ✅ Correct: Move complex logic to component
export class MyComponent {
  get currentField() {
    return this.user[this.getField()];
  }
  
  set currentField(value) {
    this.user[this.getField()] = value;
  }
}

<!-- ✅ Correct: Use computed property -->
<input value.bind="currentField & validate">