Ability to disable returning to a previous tab when a hardware back button is pressed

[mnasyrov]

Short description of the problem:

An application has root tab-based navigation. When a hardware back button is pressed a previous tab is selected until selection history is empty, only after that the application is exited.

What behavior are you expecting?

A way to disable current behaviour for a particular case: when a hardware back button is pressed then an application is exited immediate regardless of tab selection history.

Which Ionic Version?
v2 (2.0.0-beta.10)

[JustinPierce]

Our Android testers noticed this behavior immediately and thought it was a bug in the app. We would also like the option for the back button to pop the navigation stack rather than go to the previous tab.

[elless]

We had the same issue. Currently, we are handling this by having the root pages of the tabs extend from this base class:

/**
 * Base class of a root page of a tab
 */
export abstract class BaseRootTabPage {
    private static HANDLER_PRIORITY = 100;  // Number bigger than 0 which is the default priority for cordova
    private isAndroid: boolean;
    private unregisterFunction: Function;

    constructor(protected platform: Platform,
        protected tab: Tab,
        protected app: App) {
        this.isAndroid = platform.is(Constants.Platforms.ANDROID);
    }

    ionViewWillEnter(): void {
        if (this.isAndroid) {
            this.unregisterFunction = this.platform.registerBackButtonAction(() => {

                // tab.getActive() == null when a view is being presented, otherwise it is defined
                if (this.tab.getActive()) {
                    // When on a root page of a tab while no view is presented - exit app
                    this.platform.exitApp();
                } else {
                    // When a view is being presented - pop that view
                    this.app.navPop();
                }
            }, BaseTabPage.HANDLER_PRIORITY);
        }
    }

    ionViewWillLeave(): void {
        if (this.isAndroid) {
            this.unregisterFunction();
        }
    }
}

[jgw96]

Hello all! Thanks for using Ionic! Since we are going to use this issue as a tracking issue for this and other back button issues on Android i will be closing this issue as a duplicate. Thanks for using ionic!