While testing the scenic example in combination with Nerves on a RPi3 with a touchscreen, it became clear that the images where not rendering. At first I thought it would be related to the Scenic RPI driver, but this was not the case. Debugging of the path variables resulted in a clear path resolving issue at compile time.
When looking a the default splash.ex the parrot image is loaded as follows:
@parrot_path :code.priv_dir(:scenic_example) |> Path.join("/static/images/scenic_parrot.png") @parrot_hash Scenic.Cache.Support.Hash.file!(@parrot_path, :sha)
:code.priv_dir(:scenic_example) will result with a path on my local file system, not on the target.
I had to fix/change this path issue with a config, but maybe this can be done in a more elegant way. My current workaround:
config :scenic_example, :priv_dir, "./_build/dev/lib/scenic_example/priv/"
config :scenic_example, :priv_dir, "/srv/erlang/lib/scenic_example-0.1.0/priv"
@parrot_file "/static/images/scenic_parrot.png" @parrot_path Application.get_env(:scenic_example, :priv_dir) |> Path.join(@parrot_file) @parrot_hash_path :code.priv_dir(:scenic_example) |> Path.join(@parrot_file) @parrot_hash Scenic.Cache.Support.Hash.file!(@parrot_hash_path, :sha)
The hash has to be calculated at compile time using the file on my local filesystem, hence the double paths.
What would be a more elegant solution to solve this?
Also when the application will be versioned, the path in rpi3.exs has to be changed also, which could be an issue in the future.
Removing the static definitions is always an option, but I think in general the static definitions will work better and easier in the future.