# AUR0775

## Error Message

`AUR0775: Invalid command "<command>" usage with [repeat]`

Where `<command>` is the binding command used (e.g., `one-time`, `from-view`).

## Description

This error occurs when the `repeat.for` attribute uses a binding command other than the allowed ones: `bind` (two-way) or `to-view` (one-way).

## Cause

The `repeat` template controller inherently works by observing changes in the source collection (the iterable provided to `repeat.for`) and updating the generated DOM elements accordingly. This requires a one-way (`to-view`) or two-way (`bind`) data flow from the view model to the view.

Using other commands like `one-time` would prevent the repeater from updating when the collection changes, and `from-view` or `two-way` don't make conceptual sense for iterating a collection *from* the view model. The `Repeat` controller's constructor explicitly checks for and disallows unsupported commands.

## Solution

Ensure that your `repeat.for` binding uses either the default (which is `to-view`) or explicitly uses `.bind` or `.to-view`.

* `repeat.for="item of items"` (implicitly uses `to-view`)
* `repeat.for="item of items & toView"` (explicitly uses `to-view`)
* `repeat.for="item of items & bind"` (uses `bind`, though `to-view` is usually sufficient)

Remove any unsupported binding commands like `.one-time`, `.from-view`, or `.two-way`.

## Example

```html
<!-- Incorrect: Using one-time command -->
<div repeat.for="item of items & oneTime">${item}</div>

<!-- Incorrect: Using from-view command -->
<div repeat.for="item of items & fromView">${item}</div>

<!-- Incorrect: Using two-way command (though .bind is allowed, .two-way alias might not be) -->
<div repeat.for="item of items & twoWay">${item}</div>

<!-- Correct: Implicitly uses to-view -->
<div repeat.for="item of items">${item}</div>

<!-- Correct: Explicitly uses to-view -->
<div repeat.for="item of items & toView">${item}</div>

<!-- Correct: Uses bind -->
<div repeat.for="item of items & bind">${item}</div>
```

## Debugging Tips

* Inspect the `repeat.for` binding in your HTML template.
* Verify the binding command used after the expression (e.g., `& oneTime`, `& fromView`).
* Remove or change the command to `to-view` (or omit it) or `bind`.


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