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;