Why is express telling me that my default view engine is not defined?

Question

I'm using nodejs and mongodb in the back end for an app I'm working on. I'm using express to test the app, and I'm trying to use ejs to render my html files. However, I'm having the issue of my default view engine not being defined.

Here is my app.js:

/**
* Module dependencies.
*/
var express = require('express')
   , routes = require('./routes')
   , user = require('./routes/user')
   , http = require('http')
   , path = require('path');
var conf = require('./conf');
var app = express();
var mongoose = require('mongoose');
   , Schema = mongoose.Schema
   , ObjectId = mongooseSchemaTypes.ObjectID;
var UserSchema = new Schema({})
   , User;
// all environments
app.set('port', process.env.PORT || 3000);
app.set('view engine', 'ejs');
app.engine('.html', require('ejs').renderFile());
app.use(express.favicon());
app.use(express.logger('dev'));
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(app.router);
app.use(express.static(path.join(__dirname, 'public')));
// development only
if ('development' == app.get('env')) {
    app.use(express.errorHandler());
}
app.get('/', routes.index);
app.get('/users', user.list);
http.createServer(app).listen(app.get('port'), function(){
    console.log('Express server listening on port ' + app.get('port'));
});

Here is my package.json:

{
  "name": "application-name",
  "version": "0.0.1",
  "private": true,
  "dependencies": {
"express": "3.3.3",
"ejs":">= 0.0.1",
"mongoose-auth": ">= 0.0.12",
"mongoose": ">=2.4.8",
"everyauth": ">=0.2.28"
  }
}

ERRORS:

Express 500 Error: Failed to lookup view "index"

at Function.app.render (/home/christian/node_modules/nave/create/node_modules/express/lib/application.js:494:17)
at ServerResponse.res.render (/home/christian/node_modules/nave/create/node_modules/express/lib/response.js:756:7)
at exports.index (/home/christian/node_modules/nave/create/routes/index.js:7:7)
at callbacks (/home/christian/node_modules/nave/create/node_modules/express/lib/router/index.js:161:37)
at param (/home/christian/node_modules/nave/create/node_modules/express/lib/router/index.js:135:11)
at pass (/home/christian/node_modules/nave/create/node_modules/express/lib/router/index.js:142:5)
at Router._dispatch (/home/christian/node_modules/nave/create/node_modules/express/lib/router/index.js:170:5)
at Object.router (/home/christian/node_modules/nave/create/node_modules/express/lib/router/index.js:33:10)
at next (/home/christian/node_modules/nave/create/node_modules/express/node_modules/connect/lib/proto.js:190:15)
at Object.methodOverride [as handle] (/home/christian/node_modules/nave/create/node_modules/express/node_modules/connect/lib/middleware/methodOverride.js:49:5)

Now when I try to run it my terminal outputs:

/home/christian/node_modules/nave/create/node_modules/express/lib/application.js:173
if ('function' != typeof fn) throw new Error('callback function required');
                                 ^
Error: callback function required
    at Function.app.engine (/home/christian/node_modules/nave/create/node_modules/express/lib/application.js:173:38)
    at Function.<anonymous> (/home/christian/node_modules/nave/create/app.js:26:9)
    at Function.app.configure (/home/christian/node_modules/nave/create/node_modules/express/lib/application.js:392:61)
    at Object.<anonymous> (/home/christian/node_modules/nave/create/app.js:23:5)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)

Any help would be greatly appreciated.

Did you try `"ejs": "*"` just to see if there's a weird version thing going on? — kentcdodds, Jul 10 '13 at 01:07

Jonathan Lonowski · Accepted Answer · 2013-07-10T03:13:18.650

34

The source of the error describes the requirements:

if (!ext && !this.defaultEngine) throw new Error('No default engine was specified and no extension was provided.');

Express expects that you either specify the view with its extension:

res.render('index.html');

Or specify a default view engine and name your views after it:

app.set('view engine', 'ejs');

// `res.render('index')` renders `index.ejs`

Regarding your edit:

if ('function' != typeof fn) throw new Error('callback function required');

The issue is with this line:

app.engine('.html', require('ejs').renderFile());

As the documentation demonstrates, app.engine() is expecting a function reference. You can do this by simply removing the () that call renderFile:

app.engine('.html', require('ejs').renderFile);

edited Jul 10 '13 at 03:13

answered Jul 10 '13 at 02:21

Jonathan Lonowski

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@ChristianGrabowski For setting a default view engine, you appear to have it in the right spot. Though, the error you added is a different issue. See my edit for that. – Jonathan Lonowski Jul 10 '13 at 03:17
Yeah, that fixed it, but now express is giving me a new error that I updated above. – Christian Grabowski Jul 10 '13 at 03:24
@ChristianGrabowski To use the default engine, the view's extension should be the engine's name. So, for `app.set('view engine', 'ejs')`, `res.render('index')` will look for `index.ejs`. Otherwise, you still have to specify the intended extension when rendering -- `res.render('index.html')`. – Jonathan Lonowski Jul 10 '13 at 03:26
I am not using the res.render(index) is it that it's required or is it just fine with app.engine('.html', require('ejs').renderFile)? – Christian Grabowski Jul 10 '13 at 13:04
@ChristianGrabowski `res.render('index')` is just an example since you didn't include how `res.render()` is being used (in `./routes/index.js` and `./routes/user.js`). But, using `app.engine('.html', ...)` is fine as long as you include the extension when rendering -- `res.render('index.html')`. – Jonathan Lonowski Jul 10 '13 at 16:58
Ok, thanks for the help, but I ended up rewriting the entire app.js from scratch and it works now. I did use some of your suggestions though, so I'll give you the credit for answering. – Christian Grabowski Jul 11 '13 at 03:09

score 2 · Answer 2 · answered Jul 10 '13 at 01:25

need to do all the app.set and app.use in an app.configure

try this

app.configure(function(){ 
    app.set('port', process.env.PORT || 3000);
    app.set('view engine', 'ejs');
    app.engine('.html', require('ejs').renderFile());
    app.use(express.favicon());
    app.use(express.logger('dev'));
    app.use(express.bodyParser());
    app.use(express.methodOverride());
    app.use(app.router);
    app.use(express.static(path.join(__dirname, 'public')));
    // development only
    if ('development' == app.get('env')) {
        app.use(express.errorHandler());
    }
});

"[*These functions are **not** required in order to use `app.set()` and other configuration methods.*](http://expressjs.com/api.html#app.configure)" It may have been at one time, but isn't now. — Jonathan Lonowski, Jul 10 '13 at 02:15

Why is express telling me that my default view engine is not defined?

2 Answers2

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