Calling View file functions from main app

First I’d ask: why do you use Views for CSV output?

You can just use nimble_csv in your controller and directly return the CSV with render text: csv_output or some such (sorry, forgot the actual Phoenix syntax).

Thanks for the reply @dimitarvp

I am using view logic to format the data in the same way as we do in our templates.

Here is a trivial example:

# in controller
def csv_users(conn, params) do
  binary = Accounts.buid_users_csv_export()
  send_download(conn, binary: binary)
end

# in Accounts.Users.ExportCSV
def buid_users_csv_export() do
    Users.list_users() 
    |> Enum.map(fn user ->
      [
        UserView.format_name(user),
        UserView.format_address(user),
      ...
      ]
     |> NimbleCSV.build_csv()
end

This is a really basic example of pseudo code but it is exactly the issue that I am facing in many places in my application. In reality, there is too much formatting to just redefine the functions locally to this module.

Any help really appreciated

What do you mean by that? CSV doesn’t need formatting.

There are too many of these “formatting” functions: UserView.format_address(user)

So am I understanding correctly: you don’t want to use nimble_csv and you want to keep using Phoenix Views for CSV formatting because the functions that output the proper CSV fields are too many?

Hi @dimitarvp. No you aren’t understanding me correctly.

I am happily using NimbleCSV. Maybe forget that I ever mentioned CSV

I think this is the crux of my question:

Given that View modules contain formatting logic, what do you do if you want to format some data in your main application (ie in lib/myapp/ as opposed to in the lib/myapp_web/ ) ?

I feel like it is not good design/practice to reference my UserView module in my Accounts.Users.ExportCSV module and wanted to understand how people would get around this issue.

They just want access for example the full_name(user) function defined in the view to fill the CSV column full_name in the CSV generating code.

@ jmurphyweb you could move your helpers in the data model and import them from your view and your csv code.

Oops, sorry for the derp.

In all Phoenix projects where I had any influence, I always moved such functions outside the _web namespace. They absolutely don’t belong there in my eyes. They are also not views per se, they are like data reshapers / transformers / whatever-you-want-to-call them.

So yep, move them to the other namespace and don’t have a care in the world.

I think this would be better reworded as “Given that View modules contain formatting code specifically for rendering one or more web-pages”. Then there would be no confusion. If it isn’t to do with a web page or API output, it doesn’t belong in the _web part of the project.

It is dirty, that’s why it feels dirty!

They absolutely don’t belong there in my eyes. They are also not views per se, they are like data reshapers / transformers / whatever-you-want-to-call them.

That’s honestly really eye opening for me. I thought this basic formatting was exactly the purpose of View modules in Phoenix!

It sounds like you are saying the View modules are specifically for putting controller/context provided data into a shape that a template will readily consume. Is that pretty much it?

Can I just double check my comprehension:

Create these data formatters somewhere in/round the User module and then alias that module in my view module for access by the templates?

I can see why that is an improvement, but something still seems a little off the me