url-metadata-parser
Version:
Request an http(s) url and scrape its metadata
53 lines • 2.08 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
const axios_1 = require("axios");
const from_1 = require("rxjs/internal/observable/from");
const operators_1 = require("rxjs/operators");
const iconvLte = require("iconv-lite");
const of_1 = require("rxjs/internal/observable/of");
const metatag_1 = require("./metatag");
class MetadataParser {
static getCharsetByBom(buf) {
const boms = new Map([
// ['utf-8', [0xEF, 0xBB, 0xBF]],
['utf-1', [0xF7, 0x64, 0x4C]],
['utf-7', [0x2B, 0x2F, 0x76, 0x38]],
['utf-7', [0x2B, 0x2F, 0x76, 0x39]],
['utf-7', [0x2B, 0x2F, 0x76, 0x2B]],
['utf-7', [0x2B, 0x2F, 0x76, 0x3F]],
['utf-7', [0x2B, 0x2F, 0x76, 0x38, 0x2D]],
['utf-8', [0xEF, 0xBB, 0xBF]],
['utf-16be', [0xFE, 0xFF]],
['utf-16le', [0xFF, 0xFE]],
['utf-ebcdic', [0xDD, 0x73, 0x66, 0x73]],
['scsu', [0x0E, 0xFE, 0xFF]],
['bocu-1', [0xFB, 0xEE, 0x28]],
['gb-18030', [0x84, 0x31, 0x95, 0x33]],
].map(([c, bytes]) => {
return [c, Buffer.from(bytes)];
}));
const startsWith = (bom) => {
return buf.slice(0, bom.length).equals(bom);
};
for (let [charset, bom] of boms) {
if (startsWith(bom)) {
return of_1.of(charset.toUpperCase());
}
}
return of_1.of(null);
}
static parse(url) {
return from_1.from(axios_1.default.get(url, {
responseType: 'arraybuffer',
})).pipe(operators_1.concatMap((res) => {
return this.getCharsetByBom(res.data).pipe(operators_1.map((charset) => {
const body = iconvLte.decode(res.data, charset || 'UTF-8');
return body.match(/<meta[^>]+>/g).map(function (val) {
return new metatag_1.Metatag(val);
});
}));
}));
}
}
exports.MetadataParser = MetadataParser;
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