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Version: v8 (beta)

Updating from Ionic 7 to 8

note

This guide assumes that you have already updated your app to the latest version of Ionic 7. Make sure you have followed the Upgrading to Ionic 7 Guide before starting this guide.

Breaking Changes

For a complete list of breaking changes from Ionic 7 to Ionic 8, please refer to the breaking changes document in the Ionic Framework repository.

Getting Started​

Angular​

  1. Ionic 8 supports Angular 16+. Update to the latest version of Angular by following the Angular Update Guide.

  2. Update to the latest version of Ionic 8:

npm install @ionic/angular@next

If you are using Ionic Angular Server and Ionic Angular Toolkit, be sure to update those as well:

npm install @ionic/angular@next @ionic/angular-server@next @ionic/angular-toolkit@11

Note: @ionic/angular-toolkit@11 requires a minimum of Angular 17. If you are still on Angular 16, then you may want to only update to to @ionic/angular-toolkit@10 instead.

  1. Update any IonBackButtonDelegate imports from @ionic/angular to import IonBackButton from @ionic/angular instead.

React​

  1. Ionic 8 supports React 17+. Update to the latest version of React:
npm install react@latest react-dom@latest
  1. Update to the latest version of Ionic 8:
npm install @ionic/react@next @ionic/react-router@next

Vue​

  1. Ionic 7 supports Vue 3.0.6+. Update to the latest version of Vue:
npm install vue@latest vue-router@latest
  1. Update to the latest version of Ionic 8:
npm install @ionic/vue@next @ionic/vue-router@next

Core​

  1. Update to the latest version of Ionic 8:
npm install @ionic/core@next

The following changes are not required to update to Ionic 8 as your application will continue to work. However, we recommend making the following changes to ensure you can use the new features in Ionic 8.

Dark Theme​

In previous versions, it was recommended to define the dark theme in the following way:

@media (prefers-color-scheme: dark) {
  body {
    /* global app variables */
  }

  .ios body {
    /* global ios app variables */
  }

  .md body {
    /* global md app variables */
  }
}

In Ionic Framework version 8, the dark theme is being distributed via css files that can be imported. Below is an example of importing a dark theme file in Angular:

/* @import '@ionic/angular/css/themes/dark.always.css'; */
/* @import "@ionic/angular/css/themes/dark.class.css"; */
@import '@ionic/angular/css/themes/dark.system.css';

The dark theme is now applied to the :root selector instead of the body selector. The :root selector represents the <html> element and is identical to the selector html, except that its specificity is higher.

While migrating to include the new dark theme files is unlikely to cause breaking changes, these new selectors can lead to unexpected overrides if custom CSS variables are being set on the body element. We recommend updating any instances where global application variables are set to target the :root selector instead.

For more information on the new dark theme files, refer to the Dark Mode documentation.

Step Color Tokens​

To better support the high contrast theme in Ionic 8, separate step colors tokens have been introduced for text and background color. Previously both text and background color were controlled by a single set of --ion-color-step-[number] tokens.

Using the newly imported dark theme mentioned above will also import these new step color tokens. However, developers will need to update any step color tokens that were manually defined in an application.

--ion-color-step-[number] usages for background color can be migrated by renaming the token to --ion-background-color-step-[number].

Example:

button {
- background: var(--ion-color-step-400);
+ background: var(--ion-background-color-step-400);
}

--ion-color-step-[number] usages for text color can be migrated by renaming the token to --ion-text-color-step-[number] and subtracting the number from 1000.

Example:

button {
- color: var(--ion-color-step-400);
+ color: var(--ion-text-color-step-600); /* 1000 - 400 = 600 */
}

Dynamic Font​

The core.css file has been updated to enable dynamic font scaling by default.

The --ion-default-dynamic-font variable has been removed and replaced with --ion-dynamic-font.

Developers who had previously chosen dynamic font scaling by activating it in their global stylesheets can revert to the default setting by removing their custom CSS. In doing so, their application will seamlessly continue utilizing dynamic font scaling as it did before. It's essential to note that altering the font-size of the html element should be avoided, as it may disrupt the proper functioning of dynamic font scaling.

Developers who want to disable dynamic font scaling can set --ion-dynamic-font: initial; in their global stylesheets. However, this is not recommended because it may introduce accessibility challenges for users who depend on enlarged font sizes.

For more information on the dynamic font, refer to the Dynamic Font Scaling documentation.

(Angular Only) angular.json CSS import order​

The angular.json file currently imports src/theme/variables.scss before importing src/global.scss. This may cause the incorrect styles to be applied when customizing the new Dark Theme changes.

We recommend having the src/global.scss file get imported first instead:

- "styles": ["src/theme/variables.scss", "src/global.scss"],
+ "styles": ["src/global.scss", "src/theme/variables.scss"],

Required Changes​

Browser Support​

The list of browsers that Ionic supports has changed. Review the Browser Support Guide to ensure you are deploying apps to supported browsers.

If you have a browserslist or .browserslistrc file, update it with the following content:

Chrome >=89
ChromeAndroid >=89
Firefox >=75
Edge >=89
Safari >=15
iOS >=15

Checkbox​

  1. Migrate any remaining instances of Checkbox to use the modern form control syntax. Additionally, remove any usages of the legacy property as the legacy form control syntax has been removed.

Input​

  1. Remove any usages of the size property. CSS should be used to specify the visible width of the input instead.
  2. Remove any usages of the accept property.
  3. Migrate any remaining instances of Input to use the modern form control syntax. Additionally, remove any usages of the legacy property as the legacy form control syntax has been removed.

Item​

  1. Remove any usages of the counter or counterFormatter properties. Use the properties of the same names on ion-input and ion-textarea instead.
  2. Remove any usages of the helper or error slots. Use the helperText and errorText properties on ion-input and ion-textarea instead.
  3. Remove any usages of the fill or shape properties. Use the properties of the same names on ion-input, ion-textarea, and ion-select instead.
  1. Update any usages of getLength to await the call before accessing the returned value as this method now returns Promise<number> instead of number.

Picker​

  1. Ionic 8 now ships with an inline ion-picker component. Developers who wish to continue using the legacy picker should update any ion-picker usages to ion-picker-legacy. The pickerController import remains unchanged. Note that the ion-picker-legacy component will be removed in an upcoming major release of Ionic.

Toast​

  1. Remove any usages of the cssClass property from ToastButton. The button CSS Shadow Part should be used instead.

Radio​

  1. Migrate any remaining instances of Radio to use the modern form control syntax. Additionally, remove any usages of the legacy property as the legacy form control syntax has been removed.

Select​

  1. Migrate any remaining instances of Select to use the modern form control syntax. Additionally, remove any usages of the legacy property as the legacy form control syntax has been removed.

Textarea​

  1. Migrate any remaining instances of Textarea to use the modern form control syntax. Additionally, remove any usages of the legacy property as the legacy form control syntax has been removed.

Toggle​

  1. Migrate any remaining instances of Toggle to use the modern form control syntax. Additionally, remove any usages of the legacy property as the legacy form control syntax has been removed.

Need Help Upgrading?​

Be sure to look at the Ionic 8 Breaking Changes Guide. There were several changes to default property and CSS Variable values that developers may need to be aware of. Only the breaking changes that require user action are listed on this page.

If you need help upgrading, please post a thread on the Ionic Forum.

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