Add attach photo and recording to group chat in Conversation App -- 2

We are using open source Conversation App ([login to view URL]) for our chat function. There is attach photo, recording and file for one to one chat. But there is no such function in the group chat (conference). We need you to add it in. You will need to show us that it works, give us the step by step documentation, and the linux script to do the conversion from original Conversation source code to the new source code with the added function.