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/* Copyright 2012 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.
*/
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class Metadata {
constructor(data) {
if (typeof data === 'string') {
// Ghostscript may produce invalid metadata, so try to repair that first.
data = this._repair(data);
// Convert the string to a DOM `Document`.
let parser = new DOMParser();
data = parser.parseFromString(data, 'application/xml');
} else if (!(data instanceof Document)) {
throw new Error('Metadata: input is not a string or `Document`');
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}
this._metadata = Object.create(null);
this._parse(data);
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}
_repair(data) {
return data.replace(/>\\376\\377([^<]+)/g, function(all, codes) {
let bytes = codes.replace(/\\([0-3])([0-7])([0-7])/g,
function(code, d1, d2, d3) {
return String.fromCharCode(d1 * 64 + d2 * 8 + d3 * 1);
});
let chars = '';
for (let i = 0, ii = bytes.length; i < ii; i += 2) {
let code = bytes.charCodeAt(i) * 256 + bytes.charCodeAt(i + 1);
if (code >= 32 && code < 127 && code !== 60 && code !== 62 &&
code !== 38) {
chars += String.fromCharCode(code);
} else {
chars += '&#x' + (0x10000 + code).toString(16).substring(1) + ';';
}
}
return '>' + chars;
});
}
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_parse(domDocument) {
let rdf = domDocument.documentElement;
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if (rdf.nodeName.toLowerCase() !== 'rdf:rdf') { // Wrapped in <xmpmeta>
rdf = rdf.firstChild;
while (rdf && rdf.nodeName.toLowerCase() !== 'rdf:rdf') {
rdf = rdf.nextSibling;
}
}
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let nodeName = rdf ? rdf.nodeName.toLowerCase() : null;
if (!rdf || nodeName !== 'rdf:rdf' || !rdf.hasChildNodes()) {
return;
}
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let children = rdf.childNodes;
for (let i = 0, ii = children.length; i < ii; i++) {
let desc = children[i];
if (desc.nodeName.toLowerCase() !== 'rdf:description') {
continue;
}
for (let j = 0, jj = desc.childNodes.length; j < jj; j++) {
if (desc.childNodes[j].nodeName.toLowerCase() !== '#text') {
let entry = desc.childNodes[j];
let name = entry.nodeName.toLowerCase();
this._metadata[name] = entry.textContent.trim();
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}
}
}
}
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get(name) {
return this._metadata[name] || null;
}
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has(name) {
return typeof this._metadata[name] !== 'undefined';
}
}
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export {
Metadata,
};