To fix the "Ensure text remains visible during webfont load" issue in an Angular application, you need to apply techniques that prevent the flash of unstyled text (FOUT) and ensure that text remains visible even while web fonts are loading. Here are the steps you can take:
1. **Apply Fallback Fonts**:
Use a generic or system font as a fallback font for your text. This ensures that your text remains visible while the web font is loading.
```css
.your-text-class {
font-family: 'Fallback Font', sans-serif;
}
```
2. **Use the `font-display` Property**:
The `font-display` property controls how the browser renders the text while the web font is loading. You can set it to `swap` to ensure that the fallback font is displayed until the web font is ready.
```css
@font-face {
font-family: 'Your Web Font';
src: url('path/to/webfont.woff2') format('woff2');
font-display: swap;
}
```
3. **Preload Web Fonts**:
Preloading the web font ensures that it's fetched and loaded early in the page loading process. You can add a preload link in the `<head>` section of your `index.html` file.
```html
<link rel="preload" href="path/to/webfont.woff2" as="font" type="font/woff2" crossorigin>
```
4. **Use Critical CSS**:
Critical CSS is the minimal CSS required to render the above-the-fold content of your page. By applying critical CSS to your HTML, you can style the important content using the fallback font and inline CSS. This ensures that the above-the-fold content is styled even before external stylesheets are loaded.
5. **Lazy Load Web Fonts**:
You can use the `font-display` property with different values like `fallback` or `optional` to control how the browser handles web fonts. Experiment with these values to find the best trade-off between performance and aesthetics for your specific use case.
6. **Use Angular's `ngIf` with `*ngIf`**:
Wrap sections of your template in Angular's `*ngIf` directive to conditionally render content once the fonts are loaded. You can use `*ngIf="appFontLoader | async"` to ensure content is displayed only when the fonts are ready.
Remember that the specific implementation may vary based on your application's structure and design. The key is to ensure that you provide a consistent and user-friendly experience during the web font loading process. Always test your changes across different browsers and devices to ensure that text remains visible and accessible during font loading.