Image.Plug.Pipeline (image_plug v0.1.0)

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The canonical, provider-neutral image-processing pipeline.

A pipeline is an ordered list of typed operation structs (under Image.Plug.Pipeline.Ops.*) plus pipeline-wide settings: the output format, an error policy, and a debug breadcrumb identifying the provider that produced it.

Pipelines are pure data. Behaviour lives in Image.Plug.Pipeline.Interpreter (executes ops), Image.Plug.Pipeline.Encoder (serialises the result), and Image.Plug.Pipeline.Normaliser (reorders, folds, validates).

Summary

Types

on_error()
op()
t()

Functions

append(pipeline, op)

Appends an operation to a pipeline.

new(options \\ [])

Builds a new, empty pipeline.

put_output(pipeline, format)

Replaces the pipeline's output (Ops.Format) struct.

Types

on_error()

@type on_error() ::
  :auto
  | :render_error_image
  | :fallback_to_source
  | :raise
  | {:status, 100..599}

op()

@type op() ::
  Image.Plug.Pipeline.Ops.Rotate.t()
  | Image.Plug.Pipeline.Ops.Trim.t()
  | Image.Plug.Pipeline.Ops.Flip.t()
  | Image.Plug.Pipeline.Ops.Resize.t()
  | Image.Plug.Pipeline.Ops.Background.t()
  | Image.Plug.Pipeline.Ops.Adjust.t()
  | Image.Plug.Pipeline.Ops.Sharpen.t()
  | Image.Plug.Pipeline.Ops.Blur.t()
  | Image.Plug.Pipeline.Ops.Border.t()
  | Image.Plug.Pipeline.Ops.Draw.t()
  | Image.Plug.Pipeline.Ops.Segment.t()

t()

@type t() :: %Image.Plug.Pipeline{
  on_error: on_error(),
  ops: [op()],
  output: Image.Plug.Pipeline.Ops.Format.t(),
  provider: nil | module()
}

Functions

append(pipeline, op)

@spec append(t(), op()) :: t()

Appends an operation to a pipeline.

Arguments

  • pipeline is an Image.Plug.Pipeline struct.

  • op is any operation struct under Image.Plug.Pipeline.Ops.*.

Returns

  • The pipeline with op appended to :ops.

Examples

iex> alias Image.Plug.Pipeline
iex> alias Image.Plug.Pipeline.Ops.Rotate
iex> p = Pipeline.append(Pipeline.new(), %Rotate{angle: 90})
iex> length(p.ops)
1

new(options \\ [])

@spec new(keyword()) :: t()

Builds a new, empty pipeline.

Options

  • :output is an Image.Plug.Pipeline.Ops.Format struct describing the encoder configuration. Defaults to %Ops.Format{} (auto format, quality 85, copyright-only metadata).

  • :on_error is the error policy. Defaults to :auto — see Image.Plug for selection semantics.

  • :provider is an optional debug breadcrumb identifying the provider module that produced the pipeline.

Returns

Examples

iex> p = Image.Plug.Pipeline.new()
iex> p.ops
[]
iex> p.output.type
:auto

put_output(pipeline, format)

@spec put_output(t(), Image.Plug.Pipeline.Ops.Format.t()) :: t()

Replaces the pipeline's output (Ops.Format) struct.

Arguments

Returns

  • The pipeline with :output replaced.

Examples

iex> alias Image.Plug.Pipeline
iex> alias Image.Plug.Pipeline.Ops.Format
iex> p = Pipeline.put_output(Pipeline.new(), %Format{type: :webp, quality: 80})
iex> p.output.type
:webp