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Pau Riosa
Pau Riosa

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Things I Learned using Phoenix LiveView in 2024

Use handle_params/3 more often rather than mount/3 for assigning.

def mount(_params, _session, socket), do: {:ok, socket}
def handle_params(params, _uri, socket) do
   {:noreply,
        socket
        |> assign_here_1(params)
        |> assign_here_2(params)}
end
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  • Use pipelines, it adds more visibility and readability to keep track of what you have added and need more to add.

  • You can also do pattern matching at handle_params/3. So whenever you need to load or assign special use-cases depending on the parameters, that would be a great thing

  • And since you are using private functions to assign, you can reuse them whenever you want in different handle_params/3

LiveView as The Source of Truth

# LiveView module
def handle_params(params, _uri, socket) do
  {:noreply,
        socket
        |> assign_here_1(params)
        |> assign_here_2(params)}
end
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# functional component
def component(assigns) do
    coffee_for_me = Coffee.get_coffee_for_me(assigns.id)
    # ...some code here
end
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  • Try to create functional components that depends on assigns coming from the liveview.

  • So instead of doing the code above, try to create something like this

def handle_params(params, _uri, socket) do
  {:noreply,
        socket
        # ...more assign here
        |> assign_coffee(params)}
end

defp assign_coffee(socket, %{"coffee" => coffee} = _params} do
   coffee = Coffee.get_coffee(coffee)
   assign(socket, coffee: coffee)
end
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attr(:coffee, Coffee, required: true)
def component(assigns) do
    # ...you can use your coffee here
    <p><%= coffee.title %><p>
end
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As much as possible, try to avoid database functions inside your functional components and make Liveview as the source of truth

Happy Coding

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