exceljs/lib/stream/xlsx/hyperlink-reader.js

Excel Workbook Manager - Read and Write xlsx and csv Files.

const {EventEmitter} = require('events');
const SAXStream = require('../../utils/sax-stream');

const Enums = require('../../doc/enums');
const RelType = require('../../xlsx/rel-type');

class HyperlinkReader extends EventEmitter {
  constructor(workbook, id) {
    super();

    // in a workbook, each sheet will have a number
    this.id = id;

    this._workbook = workbook;
  }

  get count() {
    return (this.hyperlinks && this.hyperlinks.length) || 0;
  }

  each(fn) {
    return this.hyperlinks.forEach(fn);
  }

  read(entry, options) {
    let emitHyperlinks = false;
    let hyperlinks = null;
    switch (options.hyperlinks) {
      case 'emit':
        emitHyperlinks = true;
        break;
      case 'cache':
        this.hyperlinks = hyperlinks = {};
        break;
      default:
        break;
    }

    if (!emitHyperlinks && !hyperlinks) {
      entry.autodrain();
      this.emit('finished');
      return;
    }

    const saxStream = new SAXStream();
    saxStream.sax.on('opentag', node => {
      if (node.name === 'Relationship') {
        const rId = node.attributes.Id;
        switch (node.attributes.Type) {
          case RelType.Hyperlink:
            {
              const relationship = {
                type: Enums.RelationshipType.Styles,
                rId,
                target: node.attributes.Target,
                targetMode: node.attributes.TargetMode,
              };
              if (emitHyperlinks) {
                this.emit('hyperlink', relationship);
              } else {
                hyperlinks[relationship.rId] = relationship;
              }
            }
            break;

          default:
            break;
        }
      }
    });

    saxStream.sax.on('end', () => {
      this.emit('finished');
    });

    // create a down-stream flow-control to regulate the stream
    const flowControl = this._workbook.flowControl.createChild();
    flowControl.pipe(saxStream, {sync: true});
    entry.pipe(flowControl);
  }
}

module.exports = HyperlinkReader;