I am a Canadian planning to fly into Manilla. I understand you need to show immigration proof of onward travel. Is a eticket/receipt on my computer sufficient, or do I need to have an actual printout?

My plan is to fly to Singapore afterwards, but I have not yet booked this leg. I do, however, have a ticket back to Canada from Shanghai in January. As an alternative, will showing this ticket to Philippines immigration be sufficient for their purposes? TIA