Expresso.Presenter.Projection (expresso v0.1.0)

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Tells how the script writes a state to the document

A projection is a rule that writes one part of the state to the document. Expresso.Presenter.Default declares the projections with three entities of the presenter DSL, and the script applies them after each change of the state:

  • attribute - writes a field of the state into an attribute of the body. attribute :view, "data-view" writes data-view="present". With flag: true, the attribute is "true" while the field is true, and the script removes it while the field is false.
  • property - writes a value of the current entry of the list of the steps into a custom property of the body. property "--fraction", :fraction writes --fraction: 0.5 at the middle of the deck.
  • mark - writes an attribute on each element that a selector finds, when a number of the element agrees with a field of the state. mark "data-selected", ".handout-page[data-thumbnail]", :slide, [{"", :selected, 0}] marks the page whose data-slide is the selected slide. The script removes the attribute from each other element that the selector finds.

A mark can have more than one value. The script writes on an element the first value whose field, plus the offset, agrees with the number of the element. With scroll: true, the script then scrolls the first marked element into its container, so the cursor of the menu stays in view.

Summary

Types

t()

The projections of a definition

Functions

from(entities)

Return the projections of the entities of a presenter module, in their order

json(projections)

Return the projections as the map that Expresso.Presenter.Program.json/1 writes

Types

t()

@type t() :: %{
  attributes: [Expresso.Presenter.Projection.Attribute.t()],
  properties: [Expresso.Presenter.Projection.Property.t()],
  marks: [Expresso.Presenter.Projection.Mark.t()]
}

The projections of a definition

Functions

from(entities)

@spec from([struct()]) :: t()

Return the projections of the entities of a presenter module, in their order

json(projections)

@spec json(t()) :: map()

Return the projections as the map that Expresso.Presenter.Program.json/1 writes

iex> alias Expresso.Presenter.Projection
iex> Projection.json(%{
...>   attributes: [%Projection.Attribute{field: :blank, name: "data-blank", flag: true}],
...>   properties: [%Projection.Property{name: "--fraction", entry: :fraction}],
...>   marks: []
...> })
%{
  "attributes" => [["blank", "data-blank", true]],
  "properties" => [["--fraction", "fraction"]],
  "marks" => []
}