# `Storehouse.Analyzer.Warm`
[🔗](https://github.com/hattoriai/storehouse/blob/v0.2.0/lib/storehouse/analyzer/warm.ex#L1)

A step (`Storehouse.Analyzer`) that makes an image's sizes before a
visitor asks for them (`Storehouse.Responsive.warm/3`), under `"warm"`:
for an app that runs its steps out of the request already
(`Storehouse.analyze_later/3`), on a queue of their own.

    steps = [
      Storehouse.Analyzer.Placeholder,
      {Storehouse.Analyzer.Warm, warm: [:photo], up_to: 3840}
    ]

    Storehouse.analyze_later(file, steps,
      then: {MyApp.Photos, :analyzed, [photo.id]},
      runner: {Storehouse.Runner.Oban, queue: :media}
    )

It needs no download of the original: alone, it reads nothing. Skipped
when warming is off (`Storehouse.Responsive.enabled?/1`), and for a file
that is not an image. `Storehouse.Responsive.warm_later/3` does the same
with no other steps.

## Options

  * `:warm` - the presets to warm (required): a name, or a list.
  * `Storehouse.Responsive.warm/3`'s, and `:enabled`.

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*Consult [api-reference.md](api-reference.md) for complete listing*