broccoli-rsvg/index.js

SVG to PNG renderer for Broccoli

'use strict'

var fs = require('fs')
var path = require('path')
var CachingWriter = require('broccoli-caching-writer')
var Rsvg = require('librsvg').Rsvg
var RSVP = require('rsvp')
var path = require('path')
var mkdirp = require('mkdirp')
var walkSync = require('walk-sync')
var _ = require('lodash')

SvgRenderer.prototype = Object.create(CachingWriter.prototype)

SvgRenderer.prototype.constructor = SvgRenderer
function SvgRenderer (inputNodes, options) {
	options = options || {}
	if (!_.isArray(inputNodes))
		inputNodes = [inputNodes]
	CachingWriter.call(this, inputNodes, {
		annotation: options.annotation
	})
	this.options = options
}

SvgRenderer.prototype.promiseForFile = function (srcDir, relativePath, destDir, version) {
	if (typeof version !== 'undefined') {
		var srcPath = path.join(srcDir, relativePath)
		var allPromises = (version['versions'] || []).map(function (v) {
			return this.promiseForFile(srcDir, relativePath, destDir, _.merge(_.omit(version, 'versions'), v))
		}.bind(this))
		allPromises.push(new RSVP.Promise(function (resolve, reject) {
			var destPath = path.join(destDir, version['path'] || getDestFilePath(relativePath))
			mkdirp.sync(path.dirname(destPath))
			render(srcPath, destPath, version, resolve)
		}))
		return RSVP.all(allPromises)
	}
}

SvgRenderer.prototype.build = function () {
	var destDir = this.outputPath
	var promises = this.inputPaths.map(function (srcDir) {
		return RSVP.all(walkSync(srcDir).map(function (relativePath) {
			if (relativePath.slice(-1) === '/') {
				mkdirp.sync(path.join(destDir, relativePath))
			} else {
				var version = this.options[relativePath] || {}
				return this.promiseForFile.bind(this)(srcDir, relativePath, destDir, version)
			}
		}.bind(this)))
	}.bind(this))
	return RSVP.all(promises)
}

function render (from, to, options, callback) {
	var svg = new Rsvg()
	svg.on('finish', function () {
		fs.writeFile(to, svg.render(_.merge({
			format: 'png',
			width: svg.width,
			height: svg.height
		}, options)).data, callback)
	})
	var transformer = options['transformer']
	fs.readFile(from, {encoding: 'UTF-8'}, function (err, data) {
		if (err) throw err
			if (typeof transformer === 'function') data = transformer(data)
				svg.end(data)
	})
}

function getDestFilePath (relativePath) {
	return relativePath.replace('svg', 'png')
}

module.exports = function (t, o) { return new SvgRenderer(t, o) }