Charging a LiPo battery while connected to the device

hi everyone,

i am working on a project wherein i have a device that runs on rechargeable LiPo battery. The device circuitry will includethe charging circuitry as well. So you will only need to hook up an the adapter or "wall wart" to charge the battery. So my question is how do I conmnect the battery, charging circuit, and main circuit in such a way that I can charge the battery while the main circuit is also running? do I have to separate the charging circuit from the main circuit?

Thanks!