You can be granted refugee status before coming to the UK, it was mainly for Syrians who were in Jordan, or other fleeing Syria, under VPRS. It is currently the UK Resettlement Scheme, and they are assessed by the UN High Commission for Refugees first who refer to the UK and other countries, were they will have leave to remain, recourse to public funds etc from day one, the same as any citizen.
The above is targeted at war torn/crisis areas and numbers are limited. There are background checks and a lot a preparation before the households come here, so clearly won't be in full swing for a country were a war started 2 weeks ago.