Expresso.Presenter.Schema (expresso v0.1.0)

Describes each value that Elixir writes for the script of the presenter

The renderer writes seven values for the script:

the program that Expresso.Presenter.Program makes;
the list of the steps that Expresso.Steps makes;
the commands of a page of the overview and of a row of the menu;
the commands of the links that Expresso.Goto makes;
the sources of the embeds that Expresso.Element.Embed makes;
the sources of the videos that Expresso.Element.Video makes;
the sources of the sounds that Expresso.Element.Audio makes.

The two windows of the presenter also send a message to each other. This module describes the JSON form of each value. It is the one source of these forms:

Expresso.Presenter.Verifier reads the fields of the state, the views, the built-in functions and the kind of each value from it.
Expresso.Test.SchemaWriter writes assets/src/schema.ts from it. That file holds a TypeScript type and a decoder for each value. A test fails when the file does not agree with this module.
Expresso.Presenter.Schema.Check examines a value with the forms. The verifier uses it for the values of a definition, and the tests use it for each value that the renderer writes.

types/0 returns the forms in order. A form can name an earlier form only. type/0 describes the terms of a form.

constants/0 returns the constants of the script, such as the kinds of element and the selectors of the elements that hold commands. Expresso.Test.SchemaWriter writes each constant into assets/src/schema.ts too, so the script and Elixir use the same values.

Summary

Types

kind()

The kind of value of a field of the state

type()

The form of a JSON value

Functions

builtins()

Return the built-in functions of the browser that a command can call

constants()

Return each constant of the script, with its name, the text that tells what it is, its form and its value

directions()

Return the directions of a swipe

fields()

Return the fields of the state and the kind of value of each field, in order

kind(atom)

Return the form of a value of a kind

regions()

Return the parts of the window under a click

transitions()

Return the built-in kinds of the transition into a slide

types()

Return each form, with its name and the text that tells what it is

views()

Return the views of the presenter

Types

kind()

@type kind() :: :index | :slide | :view | :boolean | :digits

The kind of value of a field of the state

type()

@type type() ::
  :boolean
  | :string
  | {:string, String.t()}
  | {:integer, integer() | nil}
  | {:number, number() | nil, number() | nil}
  | {:literal, String.t() | boolean() | integer()}
  | {:enum, [String.t()]}
  | {:nullable, type()}
  | {:list, type()}
  | {:tuple, [type()]}
  | {:object, [{atom(), type()}]}
  | {:open_object, [{atom(), type()}]}
  | {:partial, [{atom(), type()}]}
  | {:record, [{atom(), type()}]}
  | {:union, [type()]}
  | {:ref, atom()}

The form of a JSON value

:boolean and :string - a value of that type.
{:string, pattern} - a string that agrees with a regular expression, in source text.
{:integer, min} - an integer that is not less than min, or any integer for nil.
{:number, min, max} - a finite number from min to max. nil sets no limit.
{:literal, value} - exactly one string, boolean or integer.
{:enum, values} - one of the strings.
{:nullable, type} - a value of the type, or null.
{:list, type} - an array of values of the type.
{:tuple, types} - an array with one value of each type, in order.
{:record, fields} - an array with one value of each field, in order. The script reads it as an object with these keys, and Expresso.Presenter.Schema.Record.write/2 writes it. Only a form with a name that starts with written_ holds a record, or a union of records with the same keys.
{:object, fields} - an object with exactly these keys.
{:open_object, fields} - an object with these keys. It can have other keys, and the decoder does not return them.
{:partial, fields} - an object with some of these keys and no other key.
{:union, types} - a value of one of the types.
{:ref, name} - the form of types/0 with that name.

Functions

builtins()

@spec builtins() :: [atom()]

Return the built-in functions of the browser that a command can call

constants()

@spec constants() :: [{atom(), String.t(), type(), term()}]

Return each constant of the script, with its name, the text that tells what it is, its form and its value

A constant comes from Elixir and goes into the script when esbuild makes the bundle, so the document does not hold it.

directions()

@spec directions() :: [atom()]

Return the directions of a swipe

fields()

@spec fields() :: [{atom(), kind()}]

Return the fields of the state and the kind of value of each field, in order

kind(atom)

@spec kind(kind()) :: type()

Return the form of a value of a kind

iex> Expresso.Presenter.Schema.kind(:slide)
{:integer, 1}

regions()

@spec regions() :: [atom()]

Return the parts of the window under a click

transitions()

@spec transitions() :: [atom()]

Return the built-in kinds of the transition into a slide

types()

@spec types() :: [{atom(), String.t(), type()}]

Return each form, with its name and the text that tells what it is

The forms come in order. A form can name an earlier form only.

views()

@spec views() :: [atom()]

Return the views of the presenter