@mnakhla/rocketrml/src/input-parser/logicalSourceParser.js

This is a forked rocketrml mapper for the RDF mapping language

const prefixhelper = require('../helper/prefixHelper');
// parses the logicalSource with the whole data, prefixes, and the id of the logicalsource
// returns the file, the type, iterator and referenceFormulation

const parseLogicalSource = (data, prefixes, id) => {
  const entry = data.find((x) => x['@id'] === id);
  if (!entry) {
    // logicalsource not found by id
    throw `parseLogicalSource(): Error during processing logicalsource: could not find id: ${id}`;
  }
  const entryWithoutPrefixes = entry;
  let source = entryWithoutPrefixes.source;
  let iterator = entryWithoutPrefixes.iterator;
  const ql = prefixhelper.checkAndRemovePrefixesFromString(
    entryWithoutPrefixes.referenceFormulation['@id'],
    prefixes,
  );
  let referenceFormulation = entryWithoutPrefixes.referenceFormulation;
  if (ql === 'CSV') {
    iterator = '$';
  }
  if (typeof source === 'object' && source['url']) {
    // In case a csvw object is used as source (e.g. ldwizard generated RML)
    source = source['url']
  }
  if (source && iterator && referenceFormulation) {
    switch (typeof referenceFormulation) {
      case 'string':
        referenceFormulation = prefixhelper.checkAndRemovePrefixesFromString(
          referenceFormulation,
          prefixes,
        );
        break;
      case 'object':
        referenceFormulation = referenceFormulation['@id'];
        if (referenceFormulation) {
          referenceFormulation = prefixhelper.checkAndRemovePrefixesFromString(
            referenceFormulation,
            prefixes,
          );
        } else {
          throw 'parseLogicalSource(): Error during processing logicalsource: referenceFormulation has no @id field';
        }
        break;
      default:
        throw 'parseLogicalSource(): Error during processing logicalsource: referenceFormulation in wrong format';
    }

    return {
      source,
      referenceFormulation,
      iterator,
    };
  }
  // not all required entries for logicalsource existing
  throw 'parseLogicalSource(): Error during processing logicalsource: could not find either source, iterator or referenceFormulation';
};

module.exports.parseLogicalSource = parseLogicalSource;