> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rebellapp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# my.canIUse

> Check whether a Mini Program API, parameter, return value, component, or attribute is supported in the current version.

Use this API to determine feature availability before using version-specific functionality. This helps ensure graceful degradation on older Mini Program versions.

## Parameters

| Property | Type   | Required | Description                                    |
| -------- | ------ | -------- | ---------------------------------------------- |
| schema   | String | Yes      | The feature schema to check (see syntax below) |

## Schema Syntax

The `my.canIUse` function accepts a dot-notation string to specify what feature to check:

<Tabs>
  <Tab title="API Checks">
    **Syntax:** `${API}.${type}.${param}.${option}`

    | Part     | Description                                                              |
    | -------- | ------------------------------------------------------------------------ |
    | `API`    | Name of the API to check                                                 |
    | `type`   | Check type: `object` (parameter), `return` (return value), or `callback` |
    | `param`  | Parameter or return property name                                        |
    | `option` | Specific option or value to check                                        |
  </Tab>

  <Tab title="Component Checks">
    **Syntax:** `${component}.${attribute}.${option}`

    | Part        | Description                       |
    | ----------- | --------------------------------- |
    | `component` | Name of the component             |
    | `attribute` | Component attribute to check      |
    | `option`    | Specific attribute value to check |
  </Tab>
</Tabs>

## Return Value

| Type    | Description                                           |
| ------- | ----------------------------------------------------- |
| Boolean | `true` if the feature is supported, `false` otherwise |

## Code Examples

### Check API Availability

```javascript theme={null}
// Check if an API exists
if (my.canIUse('getFileInfo')) {
  my.getFileInfo({
    filePath: 'path/to/file',
    success: (res) => {
      console.log(res.size);
    }
  });
} else {
  console.log('getFileInfo API not supported');
}
```

### Check API Parameter Support

```javascript theme={null}
// Check if a specific parameter is supported
if (my.canIUse('getLocation.object.type')) {
  my.getLocation({
    type: 'gcj02',
    success: (res) => {
      console.log(res.latitude, res.longitude);
    }
  });
}
```

### Check Return Value Support

```javascript theme={null}
// Check if a return property exists
if (my.canIUse('getSystemInfo.return.brand')) {
  my.getSystemInfo({
    success: (res) => {
      console.log('Device brand:', res.brand);
    }
  });
}
```

### Check Component Attribute Support

```javascript theme={null}
// Check if a component attribute value is supported
if (my.canIUse('button.open-type.getAuthorize')) {
  // Can use button with open-type="getAuthorize"
}
```

## Common Use Cases

<AccordionGroup>
  <Accordion title="Graceful Degradation">
    Use `my.canIUse` to provide fallback behavior when features aren't available:

    ```javascript theme={null}
    function getLocation() {
      if (my.canIUse('getLocation.object.type')) {
        // Use enhanced location API
        my.getLocation({
          type: 'gcj02',
          success: handleLocation
        });
      } else {
        // Fallback to basic location
        my.getLocation({
          success: handleLocation
        });
      }
    }
    ```
  </Accordion>

  <Accordion title="Feature Detection for UI">
    Conditionally render UI elements based on platform capabilities:

    ```javascript theme={null}
    Page({
      data: {
        canAuthorize: false
      },
      onLoad() {
        this.setData({
          canAuthorize: my.canIUse('button.open-type.getAuthorize')
        });
      }
    });
    ```
  </Accordion>
</AccordionGroup>

<Tip>
  Always check feature availability before using APIs that may not be present in all Mini Program versions. This ensures your app works correctly across different platform versions.
</Tip>