interpolateSkeleton method

String interpolateSkeleton(CodeSample sample, String skeleton)

Interpolates the injections into an HTML skeleton file.

Similar to interpolateTemplate, but we are only looking for code- components, and we care about the order of the injections.

Takes into account the type and doesn't substitute in the id and the app if not a SnippetType.sample snippet.

Implementation

String interpolateSkeleton(
  CodeSample sample,
  String skeleton,
) {
  final List<String> codeParts = <String>[];
  const HtmlEscape htmlEscape = HtmlEscape();
  String? language;
  for (final TemplateInjection injection in sample.parts) {
    if (!injection.name.startsWith('code')) {
      continue;
    }
    codeParts.addAll(injection.stringContents);
    if (injection.language.isNotEmpty) {
      language = injection.language;
    }
    codeParts.addAll(<String>['', '// ...', '']);
  }
  if (codeParts.length > 3) {
    codeParts.removeRange(codeParts.length - 3, codeParts.length);
  }
  // Only insert a div for the description if there actually is some text there.
  // This means that the {{description}} marker in the skeleton needs to
  // be inside of an {@inject-html} block.
  final String description = sample.description.trim().isNotEmpty
      ? '<div class="snippet-description">{@end-inject-html}${sample.description.trim()}{@inject-html}</div>'
      : '';

  // DartPad only supports stable or main as valid channels. Use main
  // if not on stable so that local runs will work (although they will
  // still take their sample code from the master docs server).
  final String channel =
      sample.metadata['channel'] == 'stable' ? 'stable' : 'main';

  final Map<String, String> substitutions = <String, String>{
    'description': description,
    'code': htmlEscape.convert(codeParts.join('\n')),
    'language': language ?? 'dart',
    'serial': '',
    'id': sample.metadata['id']! as String,
    'channel': channel,
    'element': sample.metadata['element'] as String? ?? sample.element,
    'app': '',
  };
  if (sample is ApplicationSample) {
    substitutions
      ..['serial'] = sample.metadata['serial']?.toString() ?? '0'
      ..['app'] = htmlEscape.convert(sample.output);
  }
  return skeleton.replaceAllMapped(
      RegExp('{{(${substitutions.keys.join('|')})}}'), (Match match) {
    return substitutions[match[1]]!;
  });
}