albanm/nsi-routes

// A route builder that create routes for applying xsl transformation
// The stylesheet source is fetched from a file and the file's changes are watched automatically

var fs = require('fs');
var path = require('path');
var libxslt = require('libxslt');

module.exports = function xsltRoute(fileName, routeName) {
    var that = this;
    var stylesheet = null;
    routeName = routeName || 'xslt.' + path.basename(fileName, '.xsl');

    that.log('info', routeName + ' - Initialize');

    if (that.options.watch) {
        fs.watch(fileName, {
            persistent: false
        }, function() {
            that.log('info', routeName + ' - Stylesheet changed');
            stylesheet = null;
        });
    }
    
    return that.wrap(function(body, headers, callback) {
        if (!stylesheet) {
            fs.readFile(fileName, 'utf8', function(err, data) {
                if (err) throw err;
                stylesheet = libxslt.parse(data);
                stylesheet.apply(body, headers, function(err, result){
                    callback(err, result, headers);
                });
            });
        } else {
            stylesheet.apply(body, headers, function(err, result){
                callback(err, result, headers);
            });
        }
    }, routeName);
};