How to send HTML in chunks using Node.js and Express?
I want to submit <head>
the stylesheets before processing the rest of the page. In PHP, I could use ob_flush()
.
I tried to do something like this:
app.set('view engine','ejs');
app.get('*',function(req,res){
res.writeHead(200,{'Content-Type':'text/html'});
res.write('<!doctype...<link rel=stylesheet...');
doDBStuff()
.then(function(data){
res.render('index',{...}); // uses EJS for templating
});
});
However, the part is res.render()
not sent. Is there a built-in way to send data with channels?
One way to do this is to manually load the EJS files and manually process them. I would also have to manually submit the appropriate headers. I prefer the inline method if it exists.
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Here's a simple PoC that does what you want:
var express = require('express');
var app = express();
var server = app.listen(3000);
app.set('views', 'views');
app.set('view engine', 'ejs');
app.get('/', function (req, res, next) {
res.write('<!-- prefix -->');
setTimeout(function() {
res.render('index', { ... }, function(err, html) {
// TODO: handle errors
res.end(html);
});
}, 1000);
});
Note that it uses a "callback option" res.render()
that you can use to render the template without sending a response (if you don't, it res.render()
will throw an error). Alternatively, you can use app.render()
that does the same.
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