> For the complete documentation index, see [llms.txt](https://docs.aurelia.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.aurelia.io/developer-guides/error-messages/0151-to-0179/aur0177.md).

# AUR0177

## Error Message

`AUR0177: Expression error: object binding patterns only support identifiers and aliases with unique, non-reserved local names: "{{expression}}"`

## Description

Object destructuring in a `repeat.for` declaration supports shallow property names and aliases whose targets are unique local identifiers. Aurelia reports this error when a parsed object declaration uses a nested pattern, an expression target, the same local name more than once, a repeat contextual name such as `$index`, the reserved `$item` name, or an Object prototype name such as `constructor`. Source properties with reserved names remain available through a safe alias.

## Example Trigger

```html
<!-- ❌ Nested object patterns are not supported -->
<div repeat.for="{ customer: { name } } of orders">
  ${name}
</div>
```

## Solution

Use shallow locals or repeat the complete object when the template needs more complex access:

```html
<!-- ✅ Shallow property and alias -->
<div repeat.for="{ id: orderId, customer } of orders">
  ${orderId}: ${customer.name}
</div>

<!-- ✅ A reserved source property can use a safe local alias -->
<div repeat.for="{ constructor: type } of orders">
  ${type}
</div>

<!-- ✅ Keep the complete object -->
<div repeat.for="order of orders">
  ${order.id}: ${order.customer.name}
</div>
```


---

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