Ionic1 + Ionic4 running side by side


A client is interested in transitioning an old Ionic 1 app to Ionic 4, and asked me to investigate the possibility of gradual upgrade (converting individual modules / pages and slowly making the transition).

I realize that requires different versions of Angular running side by side (possible) and some modification to the build process (painful but also possible).

I was wondering if anyone did anything similar? Initial investigation seems to indicate this will be quite difficult and I was wondering if anyone was able to do this before? Or if there are blockers I’m not aware of


I asked a similar question a while ago with a potential solution, but I haven’t started implementing it yet, and didn’t get any responses so far.

I am hoping for a custom build of Ionic v4 where all v4 component names are prefixed like <v4-ion-button> etc… to allow for easier and incremental migration/adoption of v4 in larger apps without conflicting with existing v1 or v3 code.

That might work, though I suspect the different Angular version might cause some minor issues - but in my case (v1 -> v4) it’s probably much more painful :confused:

v4 is just standard web-components, not dependent upon angular or anything. I think the only problem is that components have same name as v3 and v1 angular-components.