feedr/source/plugins/json.js

Use feedr to fetch the data from a remote url, respect its caching, and parse its data. Despite its name, it's not just for feed data but also for all data that you can feed into it (including binary data).

'use strict'

module.exports.parse = function parseJSON(
	{ feedr, feed, response, data },
	next
) {
	// Detect
	const isJSON =
		feed.parse === 'json' ||
		['.json', '.jsonp', '.js'].indexOf(feed.extension) !== -1 ||
		response.headers['content-type'].indexOf('javascript') !== -1 ||
		response.headers['content-type'].indexOf('json') !== -1
	if (!isJSON) {
		next()
		return
	}

	// strip comments, whitespace, and semicolons from the start and finish
	// targets facebook graph api
	data = data
		.toString()
		.trim()
		.replace(/(^([\s;]|\/\*\*\/)+|[\s;]+$)/g, '')

	// strip the jsonp callback if it exists
	data = data.replace(/^[a-z0-9]+/gi, '').replace(/^\(|\)$/g, '')

	// try parse jsonp
	try {
		data = JSON.parse(data)
	} catch (err) {
		// strip some dodgy escaping
		data = data.replace(/\\'/g, "'")

		// try parse
		try {
			data = JSON.parse(data)
		} catch (err) {
			next(err)
			return
		}
	}

	// Clean the data if desired
	if (feed.clean) {
		feedr.log('debug', `Feedr is cleaning data from [${feed.url}]`)
		data = feedr.cleanData(data)
	}

	// Write
	next(null, data)
}