Proposal for API changes

[mguterl]

Hey @route, I am curious what you think about a few changes that I would like to propose. I have been working on these changes, but I wanted to run them by you before I submit a PR.

Batch operations into a single command / copy by default

Right now if you want to change the format and resize an image, it will invoke the mogrify command multiple times. Instead I propose that we batch the operations and run them as a single invocation of mogrify.

One of the principals of Elixir is immutability and I think it would be awesome if mogrify embraced this too. Instead of defaulting to modifying the existing image on the filesystem, I think it would be interesting to default to creating a new image.

Current

If we wanted to resize, format, an image without overwriting the original we would:

open("input.jpg") |> copy |> resize("100x100") |> format("png")

This will invoke mogrify twice, once to resize, and once to change the format.

Proposed

Save to a temporary directory

image = open("input.jpg") |> resize("100x100") |> format("png") |> save
image.path # => some path in the temp directory

Save to an explicit path

image = open("input.jpg") |> resize("100x100") |> format("png") |> save("new.png")

What do you think? Is this something that you would be interested in merging into mogrify?

[route]

@mguterl I thought about current design too and I agree with you! Go ahead let's make it better!

[mguterl]

Thanks @route! I'll send something over in the next few days.

[imranismail]

Hey @mguterl have you started working on this? I can help.

[mguterl]

@imranismail - I have everything complete except format. https://github.com/mguterl/mogrify/tree/batch-operations-into-single-command

I was sick all of last week so I'm a bit behind, but finishing up format shouldn't be too hard. It is different than the other operations because it requires changing the extension of the filename generated.

[route]

@mguterl no rush, it's done when it's done. Get better!

[route]

Hey guys! Any updates?

[mbriggs]

about to use mogrify for a work project, I wouldnt mind helping get this out if there is stuff still to be done

[mguterl]

I haven't updated anything since my last comment, everything except for the format command is supported here: https://github.com/mguterl/mogrify/tree/batch-operations-into-single-command

[tomjoro]

Hi, great stuff.. was looking at how this is progressing, and have a few questions/notes.

I've was looking at https://github.com/minimagick/minimagick. In the current proposal (this issue) there's no way to differentiate between sequential execution, and combining options in a single run. It would be nice if it were possible to somehow specify this.

From minimagick:

image.combine_options do |b|
  b.resize "250x200>"
  b.rotate "-90"
  b.flip
end # the command gets executed

# the following executes in separate commands

  image.resize "200x200>"
  image.rotate "-90"
  image.write "output.png"

Maybe?? " |> batch |> resize("200x200>") |> rotate("-90") |> run"??

also, the current 'copy' is interesting. In minimagick it's just specified up front when you 'open' or 'new' the file. Can 'copy' be applied multiple times in the current pipeline?

[mbriggs]

as someone who has done a LOT of work with minimagick, pretty much the only time you dont want to combine options is when you start working off of a different set of inputs. I think in terms of elixir syntax, it makes sense that combine_options maps to a pipeline, if you want to do a different set of operations on a new set of inputs, start a new pipeline.

[route]

I'll pickup this work

[talklittle]

Created a PR building off @mguterl's work, adding batching for format/2 and the newer functions auto_orient/1 and custom/3.

https://github.com/route/mogrify/pull/12

[talklittle]

One change I made to the original proposal is giving save/2 a couple options: :in_place and :path

So there's 3 variants:

# temp dir
image = open("input.jpg") |> resize("100x100") |> save

# specify a path
image = open("input.jpg") |> resize("100x100") |> save(path: "new.jpg")

# overwrite original; ignores :path option if specified
image = open("input.jpg") |> resize("100x100") |> save(in_place: true)

[mguterl]

@talklittle this looks really good. I really appreciate you taking this over and pushing it to completion.

[talklittle]

12 was merged, so my first action as GitHub repo collaborator is to close this issue. Hooray

[route]

Thanks everyone 👍