modules/xmp_metadata.js

/** ====================================================================
 * @license
 * jsPDF XMP metadata plugin
 * Copyright (c) 2016 Jussi Utunen, u-jussi@suomi24.fi
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * ====================================================================
 */

import { jsPDF } from "../jspdf.js";

/**
 * @name xmp_metadata
 * @module
 */
(function(jsPDFAPI) {
  "use strict";

  var postPutResources = function() {
    var xmpmeta_beginning = '<x:xmpmeta xmlns:x="adobe:ns:meta/">';
    var rdf_beginning =
      '<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"><rdf:Description rdf:about="" xmlns:jspdf="' +
      this.internal.__metadata__.namespaceuri +
      '"><jspdf:metadata>';
    var rdf_ending = "</jspdf:metadata></rdf:Description></rdf:RDF>";
    var xmpmeta_ending = "</x:xmpmeta>";
    var utf8_xmpmeta_beginning = unescape(
      encodeURIComponent(xmpmeta_beginning)
    );
    var utf8_rdf_beginning = unescape(encodeURIComponent(rdf_beginning));
    var utf8_metadata = unescape(
      encodeURIComponent(this.internal.__metadata__.metadata)
    );
    var utf8_rdf_ending = unescape(encodeURIComponent(rdf_ending));
    var utf8_xmpmeta_ending = unescape(encodeURIComponent(xmpmeta_ending));

    var total_len =
      utf8_rdf_beginning.length +
      utf8_metadata.length +
      utf8_rdf_ending.length +
      utf8_xmpmeta_beginning.length +
      utf8_xmpmeta_ending.length;

    this.internal.__metadata__.metadata_object_number = this.internal.newObject();
    this.internal.write(
      "<< /Type /Metadata /Subtype /XML /Length " + total_len + " >>"
    );
    this.internal.write("stream");
    this.internal.write(
      utf8_xmpmeta_beginning +
        utf8_rdf_beginning +
        utf8_metadata +
        utf8_rdf_ending +
        utf8_xmpmeta_ending
    );
    this.internal.write("endstream");
    this.internal.write("endobj");
  };

  var putCatalog = function() {
    if (this.internal.__metadata__.metadata_object_number) {
      this.internal.write(
        "/Metadata " +
          this.internal.__metadata__.metadata_object_number +
          " 0 R"
      );
    }
  };

  /**
   * Adds XMP formatted metadata to PDF
   *
   * @name addMetadata
   * @function
   * @param {String} metadata The actual metadata to be added. The metadata shall be stored as XMP simple value. Note that if the metadata string contains XML markup characters "<", ">" or "&", those characters should be written using XML entities.
   * @param {String} namespaceuri Sets the namespace URI for the metadata. Last character should be slash or hash.
   * @returns {jsPDF} jsPDF-instance
   */
  jsPDFAPI.addMetadata = function(metadata, namespaceuri) {
    if (typeof this.internal.__metadata__ === "undefined") {
      this.internal.__metadata__ = {
        metadata: metadata,
        namespaceuri: namespaceuri || "http://jspdf.default.namespaceuri/"
      };
      this.internal.events.subscribe("putCatalog", putCatalog);

      this.internal.events.subscribe("postPutResources", postPutResources);
    }
    return this;
  };
})(jsPDF.API);