pdfjs-dist/lib/display/metadata.js

/* Copyright 2017 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
'use strict';

var sharedUtil = require('../shared/util.js');
var error = sharedUtil.error;
function fixMetadata(meta) {
  return meta.replace(/>\\376\\377([^<]+)/g, function (all, codes) {
    var bytes = codes.replace(/\\([0-3])([0-7])([0-7])/g, function (code, d1, d2, d3) {
      return String.fromCharCode(d1 * 64 + d2 * 8 + d3 * 1);
    });
    var chars = '';
    for (var i = 0; i < bytes.length; i += 2) {
      var code = bytes.charCodeAt(i) * 256 + bytes.charCodeAt(i + 1);
      chars += code >= 32 && code < 127 && code !== 60 && code !== 62 && code !== 38 ? String.fromCharCode(code) : '&#x' + (0x10000 + code).toString(16).substring(1) + ';';
    }
    return '>' + chars;
  });
}
function Metadata(meta) {
  if (typeof meta === 'string') {
    meta = fixMetadata(meta);
    var parser = new DOMParser();
    meta = parser.parseFromString(meta, 'application/xml');
  } else if (!(meta instanceof Document)) {
    error('Metadata: Invalid metadata object');
  }
  this.metaDocument = meta;
  this.metadata = Object.create(null);
  this.parse();
}
Metadata.prototype = {
  parse: function Metadata_parse() {
    var doc = this.metaDocument;
    var rdf = doc.documentElement;
    if (rdf.nodeName.toLowerCase() !== 'rdf:rdf') {
      rdf = rdf.firstChild;
      while (rdf && rdf.nodeName.toLowerCase() !== 'rdf:rdf') {
        rdf = rdf.nextSibling;
      }
    }
    var nodeName = rdf ? rdf.nodeName.toLowerCase() : null;
    if (!rdf || nodeName !== 'rdf:rdf' || !rdf.hasChildNodes()) {
      return;
    }
    var children = rdf.childNodes,
        desc,
        entry,
        name,
        i,
        ii,
        length,
        iLength;
    for (i = 0, length = children.length; i < length; i++) {
      desc = children[i];
      if (desc.nodeName.toLowerCase() !== 'rdf:description') {
        continue;
      }
      for (ii = 0, iLength = desc.childNodes.length; ii < iLength; ii++) {
        if (desc.childNodes[ii].nodeName.toLowerCase() !== '#text') {
          entry = desc.childNodes[ii];
          name = entry.nodeName.toLowerCase();
          this.metadata[name] = entry.textContent.trim();
        }
      }
    }
  },
  get: function Metadata_get(name) {
    return this.metadata[name] || null;
  },
  has: function Metadata_has(name) {
    return typeof this.metadata[name] !== 'undefined';
  }
};
exports.Metadata = Metadata;