Renaming ROM::CommandRegistry#as to #map_to

[c0]

One of the things that's confusing as a new ROM user is that #as is used with a mapper. From the TODO example —

class TaskMapper < ROM::Mapper
  relation :tasks
  model Task
end

class TasksRelation < ROM::Relation[:sql]
end

When I run —

rom.relation(:tasks).as(:tasks)

It's not clear what the second :tasks is or where it comes from.

I would like to recommend it be renamed to be more descriptive like map_to. Open to other ideas.

rom.relation(:tasks).map_to(:tasks)

[nepalez]

@co, actually the mapper can map data without any model at all -- to pure hash. That's why naming it after the model is not a good idea. Instead, you can explicitly define the name of the mapper:

class TaskMapper < ROM::Mapper
  relation :tasks
  register_as :mapper_name
  model Task
end

then

rom.relation(:tasks).as(:mapper_name)

[c0]

@nepalez I don't think the confusion is in the naming of the mapper, but that #as does not have any indication that it's using a mapper.

rom.relation(:tasks).as(:tasks)

# as opposed to
rom.relation(:tasks).map_to(:tasks)

# or even
rom.relation(:tasks).mapper(:tasks)

[nepalez]

I see. As for me, I feel conformed with as, but maybe you're right.
I think the substantial part of the confusion is a lack of documentation. Feel it as a stimulus for myself to write it faster :)

[c0]

I agree that documentation is immensely useful, but it's better when the code is clear without it. Both are needed 😄

[solnic]

as is an alias of map_with and we still haven’t decided which one is
better :)

On Thu, May 21, 2015 at 4:32 PM Caleb Wright notifications@github.com
wrote:

I agree that documentation is immensely useful, but it's better when the
code is clear without it. Both are needed :)

—
Reply to this email directly or view it on GitHub
#235 (comment).

[c0]

@solnic good to know. I personally like #map_with

[solnic]

btw you can pass multiple mapper names there ie rom.relation(:users).map_with(:entity, :view_presenter) which for me is an awesome feature :D

[cflipse]

eh, I actually prefer as ... I want to get the results of this relation as a :user_with_tasks ... makes plenty of sense.

[solnic]

me too, it reads nice imo just like you said. I guess we need to make a decision and stick to just one for 1.0.0 :)

[maetl]

I prefer as too. Having map_with there as an alias is okay from my perspective. It’s potentially a more intricate API than it needs to be, but I can see uses of both for readability reasons, depending on the particular style of client code.

For example, Sequel aliases where and filter.

[c0]

The way I read as is that it's expecting a noun. i.e. the object/model you'll end up with. I see mappers more as verbs and transformative rather than an end result. So something like rom.relation(:users).through(:entity, :view_presenter) makes more sense.

At the end of the day, I'll follow the consensus. I've been a ruby dev for a number of years, but am new to rom-rb and just wanted to surface some things that may be difficult for newcomers :)

[solnic]

Let's see what people prefer and decide for 1.0.0 how it should be named. Closing this for now.

[c0]

Sounds like a plan. Thanks everyone for the feedback!