History management

Problem description

In applications developed, history management is always different. You often need to manipulate history to remove previous route, as for example :

• During FTU, you should be able to navigate through steps, but once FTU complete, you should not be able to go back to FTU
• When navigating deeply between program info and related, you may need to skip some steps when pressing back
• …

Moreover, when routing back to a screen you sometimes want to not redo everything (data loading, data connection…), because you just want to go back to the latest state. Currently in that case, you are adding a flag in the context.

Finally, it is observed that current implementation in RouterManager save routes till infinity. Everything is stored when using route methods, but it is never cleared. This could lead to memory issues.

To sum up needs:

• You need to easily override back behavior.
• You need to identify back navigation.
• You want to avoid memory leak on history management.

Proposed solution

Usage of routeToPrevious methods on RouterManager#

Using routeToPrevious method will allow you to use mixing MHistoryRouter that is responsible for history management. It will automatically add two options to the context:

• skipHistory: true to prevent add of this route to history
• isBack: true to identify back navigation if needed

By default, with usage of AbstractMHistoryRouter, you will be redirected to previous route.

As you can send options to route, you can send options to routeToPrevious that will be used to call route with previous route name. Those options will override potential stored options used for the first routing to this routeName.

Create implementation of MHistoryRouter#

If you need a more complex implementation of previous behavior, you will need to create your own implementation of MHistoryRouterthat which inherits from AbstractMHistoryRouter. Then, you will need to override _getPreviousRoute that is allowed to manipulate _routesHistory stored.

Default implementation is the following :

_getPreviousRoute: function () {
  this._routesHistory.pop();
  return this._routesHistory.slice(-1)[0];
}

By using condition here, you can do… whatever you want and finally return an element of the _routesHistory.

Conclusion

By using routeToPrevious you will :

• always have an identifier for back navigation (isBack)
• be able to implement `_getPreviousRoute`` to have specific behavior
• prevent memory leak by having an entry point to manage stored history