Inject javascript code into html with Express

Question

I am writing a web application using Express framework to generate Impress.js presentations and apply a visual editor on them. I have set up the app.js for only getting the .html file but I want to inject a javascript code from a separate file before the body closing tag of the .html file.

For example, I will have a route handler /edit and then the script will be triggered after it have been injected into the html code.

var express = require('express');

var app = express();


app.configure(function(){
    app.use(express.static(__dirname + '/public'));
});

app.get('/:file', function(req, res) {
  res.sendfile(__dirname + '/public' + file);
});

app.listen(3000);
console.log('Listening on port 3000');

Any ideas on how to achieve this would be more than welcome!

Ticon

Answer 1

Just an idea, but you could use something like cheerio to append a script to the body

app.get('/:file', function(req, res) {
  var html = fs.readFileSync(__dirname + '/public' + file, 'utf8');
  var $ = cheerio.load(html);
  var scriptNode = '<script>alert("script appended!");</script>';
  $('body').append(scriptNode);
  res.send($.html());
});

Eclecticism

It works! But now any other scripts already embedded in the .html aren't executed. How can I fix that? Thank you. – Ticon

what do you mean they arent executed? did it remove them? was there an error? please detail – Eclecticism

when I do console.log($.html()); I can see the scripts, eg. <script src="js/main.js"></script> in the html but they aren't triggered like the appended scriptNode. I didn't have this problem with the code I have in the description. – Ticon

if you say the scripts arent running on the page when it loads, you need to be looking at the browser console to see if there are any client-side js errors – Eclecticism

You are right I forgot to configure again express.static server. Thanks again for the help! – Ticon