> For the complete documentation index, see [llms.txt](https://docs.ecwid.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ecwid.com/site-themes/develop-site-themes/sections/ui-helpers/utility-functions.md).

# Utility functions

This page documents non-composable helper functions.\
For all `use*` APIs, see [Composables](/site-themes/develop-site-themes/sections/ui-helpers/composables.md)

```typescript
import {
  createTextStyle,
  getColorHex,
  getBackgroundStyle,
  getContrastTextColor,
  isColorDark,
  getCurrentLanguageCode,
} from '@lightspeed/crane-api';
```

### Reference

| Function                                                                 | Arguments                                                                                                               | Purpose                                                                                          |
| ------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| `createTextStyle(design, options?)`                                      | `design`: TextDesignData; `options?`: style defaults/overrides                                                          | Build CSS text styles                                                                            |
| `getColorHex(color, fallback?)`                                          | `color`: color-like value; `fallback?`: hex fallback                                                                    | Extract color hex string                                                                         |
| `getBackgroundStyle(design, options?)`                                   | `design`: BackgroundDesignData; `options?`: gradient direction/fallbacks                                                | Build CSS background style value                                                                 |
| `isColorDark(color)`                                                     | `color`: color-like value                                                                                               | Check if color is dark                                                                           |
| `getContrastTextColor(backgroundColor, darkTextColor?, lightTextColor?)` | `backgroundColor`: required; `darkTextColor?`: text for light backgrounds; `lightTextColor?`: text for dark backgrounds | Return readable contrast text color                                                              |
| `getCurrentLanguageCode(languages)`                                      | `languages`: `Language[] \| undefined`                                                                                  | Return current language code from site languages array. Fallback chain: selected → main → `'en'` |

### Examples

```typescript
const titleDesign = useTextElementDesign<Design>('title');
const titleStyle = computed(() =>
  createTextStyle(titleDesign, { defaultSize: 24 }),
);

const dark = isColorDark('#1F2937');
const textColor = getContrastTextColor('#1F2937');
const textColorCustom = getContrastTextColor('#1F2937', '#111111', '#FAFAFA');

const bgDesign = useBackgroundElementDesign<Design>('section_bg');
const bgValue = getBackgroundStyle(bgDesign, { fallbackColor: '#FFFFFF' });
```

### Notes

#### `getBackgroundStyle` — gradient fallback behaviour

When `background.type === 'gradient'`, `fromColor` and `toColor` are each resolved independently via `getColorHex`:

* If a colour is missing and **`fallbackColor` is omitted** (defaults to `''`), `getColorHex` returns `''` and the function returns `{}` (no style applied).
* If a colour is missing and **`fallbackColor` is a non-empty string**, the missing stop is replaced by that fallback. This can produce a gradient where both stops are identical (e.g. `linear-gradient(to right, #FFFFFF, #FFFFFF)`), which is valid CSS but visually equivalent to a solid colour.

Keep this in mind when debugging unexpected gradient output.

#### `useButtonStyles` — font weight is always `400`

Unlike `createTextStyle`, which respects the `bold` property from `TextDesignData`, `useButtonStyles` always sets `fontWeight: '400'` regardless of any bold-related properties in `ButtonDesignData`. This is intentional — button typography weight is considered a concern of the consuming component's own CSS, not of the design data.


---

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