Added new @iiif/parser/strict for converting P3

[stephenwf]

Adds new utility for validating and fixing Presentation 3 that may not be valid.

Note: this will not automatically upgrade Presentation 2.

import { presentation3StrictUpgrade } from '@iiif/parser/strict';

const manifest = fetch('https://example.org/manifest').then(r => r.json());

const upgradedManifest = presentation3StrictUpgrade(manifest);

// Should now be valid Presentation 3

You can also get a list of issues with the second argument.

const manifest = {
  id: 'https://example.org',
  type: 'Manifest',
  label: 'Wrong label',
};

const state = { warnings: [] as string[] };
const upgraded = presentation3StrictUpgrade(manifest as any, state);

upgraded.label; // { none: ['Wrong label'] }
state.warnings[0]; // "label" should be a language map instead found a string

Currently supported:

• Various invalid language map formats
  • single strings {"label": "some label"}
  • arrays of strings {"label": ["some label"]}
  • maps without values {"label": {"en": "some label"}}
  • maps with objects {"label": { en: { INVALID: 'this is not valid' } }}
• Properties that should be arrays are wrapped (e.g. behavior)
• Properties that shouldn't be arrays are unwrapped (e.g. format)
• Ensures that heights and widths are JSON numbers and not floats
• Ensures that duration is a valid float
• Ensures that required statements and metadata have both labels and values
• Ensures rights statement starts with http (may be flaky with custom values)
• Validates navDate against regular expression from W3C (and removes whitespace)
• Ensures Manifests only contain Canvases
• Ensures Canvases only contain Annotation Pages
• Ensures Annotation Pages only contain Annotations
• Ensures accompanyingCanvas and placeholderCanvas are type Canvas (only warning)

This is built to be expanded on, and improved if there are other common pitfalls out there. Any fix should be accompanied with a descriptive warning that can be picked up. This allows it to be used both for compatibility and for validation.

There are also other possible validations that may not be possible to fix, but could be worth warning:

• Duration on a canvas without duration supporting resources
• Image resources without height/width
• Audio/Video without duration
• Audio/Video with duration that is out of bounds
• Painting Annotations that target different canvases

[stephenwf]

part of: #19