Add idx to router.object

[tatethurston]

Describe the feature you'd like to request

I'd like to propose adding idx to the router.object.idx is included in the history state on every new history entry.

This is valuable for reporting purposes such as the number of page views in the current session.

It's also valuable when building native-like applications using nextjs, particularly for back button behaviors. When replicating a native like experience, it's helpful to be able to check if a programatic router.back() would kick the user out of the app, and if so, fallback to another page (like a Homepage). This pattern frequently comes up for back buttons rendered on an error page and settings pages.

Describe the solution you'd like

A new idx field (or perhaps pageCount / pageIndex?) added to the router object.

Describe alternatives you've considered

1. Accessing history.state.idx directly. This works, but is undocumented and I'm concerned about the field changing or being removed in a next update and application code silently breaking.

2. Another option would be to include a fallback option with router.back so that users aren't backed out of the application.

[AkifumiSato]

+1
Created an implementation PR to add idx to router.
#35681

[tatethurston]

I think this ask should be a separate feature request.

[mramadanahmed]

@tatethurston Many thanks for your quick response. Sure it could be a new feature request. However, I posted that here because I saw it as a bug with the second point in your request regarding to the back fallback

Another option would be to include a fallback option with router.back so that users aren't backed out of the application.

I achieved the same as well using the idx, but lets take the following scenario.

The user open the website and navigate until the idx become 4, then eventually the user refresh the page from the address bar. Now the idx will be 0 not 4 and user will be stuck in the fallback in that page despite he has 4 steps back still valid inside the application

Hopefully if you already implement the back button fallback to confirm the behavior.

Kindly recommend

[tatethurston]

@mramadanahmed You are right — great catch. That would be a useful property for the back button behavior.

[mramadanahmed]

Bug #36662 is created to track that issue

[AkifumiSato]

I have already created a pull request, as I put on the issue.
I don't know if it will be merged or not since there is no response.
Any help would be greatly appreciated!