feed-watch/lib/modules/FeedParser.js

A highly configurable lightweight module for watching/emitting changes in rss feeds

"use strict";
var __assign = (this && this.__assign) || function () {
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};
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
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        step((generator = generator.apply(thisArg, _arguments || [])).next());
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};
var __generator = (this && this.__generator) || function (thisArg, body) {
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};
Object.defineProperty(exports, "__esModule", { value: true });
var FeedParser = require("feedparser");
var feedparser_1 = require("feedparser");
exports.FeedParserOptions = feedparser_1.Options;
var axios_1 = require("axios");
var iconv_1 = require("iconv");
var zlib = require("zlib");
function getParams(str) {
    return str.split(';').reduce(function (params, param) {
        var _a;
        var _b = param.split('=').map(function (part) { return part.trim(); }), key = _b[0], value = _b[1];
        if (key != null && value != null) {
            return __assign(__assign({}, params), (_a = {}, _a[key] = value, _a));
        }
        return params;
    }, {});
}
function throughDecompressor(stream) {
    var encoding = stream.headers['content-encoding'] || 'identity';
    var decompress;
    if (encoding.match(/\bdeflate\b/)) {
        decompress = zlib.createInflate();
    }
    else if (encoding.match(/\bgzip\b/)) {
        decompress = zlib.createGunzip();
    }
    return decompress ? stream.pipe(decompress) : stream;
}
function throughTranslator(stream) {
    var charset = getParams(stream.headers['content-type'] || '').charset;
    if (charset && !/utf-*8/i.test(charset)) {
        try {
            var iconv = new iconv_1.Iconv(charset, 'utf-8');
            iconv.on('error', function (err) {
                stream.emit('error', err);
            });
            return stream.pipe(iconv);
        }
        catch (err) {
            stream.emit('error', err);
        }
    }
    return stream;
}
function get(url, axiosOpts, parserOpts) {
    return __awaiter(this, void 0, void 0, function () {
        var posts, feedparser, stream;
        return __generator(this, function (_a) {
            switch (_a.label) {
                case 0:
                    posts = [];
                    feedparser = new FeedParser(parserOpts);
                    return [4, axios_1.default.get(url, __assign(__assign({}, axiosOpts), { responseType: 'stream' }))];
                case 1:
                    stream = (_a.sent()).data;
                    if (stream.statusCode !== 200)
                        throw new Error('Bad Status Code');
                    throughTranslator(throughDecompressor(stream)).pipe(feedparser);
                    feedparser.on('readable', function () {
                        var post;
                        while ((post = feedparser.read())) {
                            posts.push(post);
                        }
                    });
                    return [4, new Promise(function (resolve, reject) {
                            stream.on('error', reject);
                            feedparser.on('error', reject);
                            feedparser.on('end', resolve);
                        })];
                case 2:
                    _a.sent();
                    return [2, posts];
            }
        });
    });
}
exports.get = get;
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