How do I render an EJS template file in Node.js? - node.js

Question

I'm using Node.js and trying to render an EJS template file. I figured out how to render strings:
var http = require('http');
var ejs = require('ejs');
var server = http.createServer(function(req, res){
res.end(ejs.render('Hello World'));
});
server.listen(3000);
How can I render an EJS template file?

Answer 1

There is a function in EJS to render files, you can just do:
ejs.renderFile(__dirname + '/template.ejs', function(err, data) {
console.log(err || data);
});
Source: Official EJS documentation

Answer 2

var fs = require('fs');
var templateString = fs.readFileSync('template.ejs', 'utf-8');
and then you do your thing:
var server = http.createServer(function(req, res){
res.end(ejs.render(templateString));
});

Answer 3

All you have to do is compile the file as a string (with optional local variables), like so:
var fs = require('fs'), ejs = require('ejs'), http = require('http'),
server, filePath;
filePath = __dirname + '/sample.html'; // this is from your current directory
fs.readFile(filePath, 'utf-8', function(error, content) {
if (error) { throw error); }
// start the server once you have the content of the file
http.createServer(function(req, res) {
// render the file using some local params
res.end(ejs.render(content, {
users: [
{ name: 'tj' },
{ name: 'mape' },
{ name: 'guillermo' }
]
});
});
});

Answer 4

#ksloan's answer is really good. I also had the same use case and did little bit of digging. The function renderFile() is overloaded. The one you will need mostly is:
renderFile(path: string,data, cb)
for example:
ejs.renderFile(__dirname + '/template.ejs', dataForTemplate, function(err, data) {
console.log(err || data)
})
where dataForTemplate is an object containing values that you need inside the template.

Answer 5

There's a synchronous version of this pattern that tightens it up a little more.
var server = http.createServer(function(req, res) {
var filePath = __dirname + '/sample.html';
var template = fs.readFileSync(filePath, 'utf8');
res.end(ejs.render(template,{}));
});
Note the use of readFileSync(). If you specify the encoding (utf8 here), the function returns a string containing your template.

Answer 6

The answer of #ksloan should be the accepted one. It uses the ejs function precisely for this purpose.
Here is an example of how to use with Bluebird:
var Promise = require('bluebird');
var path = require('path');
var ejs = Promise.promisifyAll(require('ejs'));
ejs.renderFileAsync(path.join(__dirname, 'template.ejs'), {context: 'my context'})
.then(function (tpl) {
console.log(tpl);
})
.catch(function (error) {
console.log(error);
});
For the sake of completeness here is a promisified version of the currently accepted answer:
var ejs = require('ejs');
var Promise = require('bluebird');
var fs = Promise.promisifyAll(require('fs'));
var path = require('path');
fs.readFileAsync(path.join(__dirname, 'template.ejs'), 'utf-8')
.then(function (tpl) {
console.log(ejs.render(tpl, {context: 'my context'}));
})
.catch(function (error) {
console.log(error);
});

Answer 7

Use ejs.renderFile(filename, data) function with async-await.
To render HTML files.
const renderHtmlFile = async () => {
try {
//Parameters inside the HTML file
let params = {firstName : 'John', lastName: 'Doe'};
let html = await ejs.renderFile(__dirname + '/template.html', params);
console.log(html);
} catch (error) {
console.log("Error occured: ", error);
}
}
To render EJS files.
const renderEjsFile = async () => {
try {
//Parameters inside the HTML file
let params = {firstName : 'John', lastName: 'Doe'};
let ejs = await ejs.renderFile(__dirname + '/template.ejs', params);
console.log(ejs);
} catch (error) {
console.log("Error occured: ", error);
}
}