Zoom to fit a3 a4 formats

Hello, Walter)
Are there any functions to rescaling diagram to a3 and a4 formats? I want create function to preview my diagram on a4 or a3 page before printing or creation png .

Are you expecting to have multiple pages?
If so, and if you are not already using the Diagram.grid, you could modify the grid to match the page size(s) that the user could pick. See this sample:
https://gojs.net/extras/printGrid.html

If you are requiring everything to fit on one page, then you might be interested in this sample:
https://gojs.net/latest/samples/singlePage.html

Thanks, I have one page)

I didn’t quite understand your examples at first, but I need to change the size of the chart (either decrease or increase) so that it fits in A3 or A4 formats. Are there same functions?

The https://gojs.net/latest/samples/singlePage.html sample does not support dynamically changing the page size. But you can adapt the code that initializes those five variables towards the beginning of the init function and also update the objects whose property values use those variables.

How I may resize all nodes and links?