MiNiMAL•3y ago

Best practices for implementing an offline application

Hey there! I'm building a full stack react-native app with Expo and a tRPC backend. I'd like for this app to be functional offline. Currently I'm accomplishing this via a simple optimistic update like:

const createUser = trpc.userCreate.useMutation({
        onMutate: async () => {
            // Cancel users fetch
            await utils.users.cancel()
            // Get current users list
            const previousData = utils.users.getData() || []
            // Append new user
            utils.users.setData([...previousData, { id: uuid.v1(), name } as User])
            return { previousData }
        },
    })

const createUser = trpc.userCreate.useMutation({
        onMutate: async () => {
            // Cancel users fetch
            await utils.users.cancel()
            // Get current users list
            const previousData = utils.users.getData() || []
            // Append new user
            utils.users.setData([...previousData, { id: uuid.v1(), name } as User])
            return { previousData }
        },
    })

This is working pretty well (it's late and I plan on extensively testing this tomorrow). I'd like to confirm what best practices, if any, have been established by the community before continuing.

1 Reply

Unknown User•3y ago

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