var view = app.views.create(".view-main", {url: "/",});

When i do this, it displays a white page and i also get this error in the console.

leaflet.js:5 Uncaught Error: Map container is already initialized.
at i._initContainer (leaflet.js:5)
at initialize (leaflet.js:5)
at new i (leaflet.js:5)
at (leaflet.js:5)
at Component.pageInit (<anonymous>:313:29)
at HTMLDivElement.l (0:1087)
at Dom7.trigger (0:1216)
at t.pageCallback (0:9090)
at HTMLDivElement.<anonymous> (0:9332)
at Dom7.each (0:1384)

Issue apparently related to some of your-side code related to leaflet library, there is no anthing like that in Framework7 itself