Why is my nunjucks page not being interpreted properly? - node.js

In a node,js app using express.js, I have a piece of middleware that redirects to a session ended page written in nunjucks where need be.
The redirection works put the page is output as written and not as html. For some reason it's not being recognised as nunjucks.
nunjucks.configure(['views',
path.join(__dirname, 'node_modules/govuk-frontend/'),
path.join(__dirname, 'node_modules/govuk-frontend/govuk/components/'),
path.join(__dirname, 'app/views/')
], {
autoescape: true,
express: app
});
const endSession = (req, res, next) => {
if (config.switchPage) {
res.render(__dirname + '/app/views/pages/session-ended.html');
return;
} else {
next();
}
};
app.use(endSession);
Elsewhere, I call the page with:
res.redirect('/decision/session-ended');
and it works fine.
I've tried swapping the sendfile for the redirect but get the following error message on the page:
This page isn’t working
localhost redirected you too many times.
Try clearing your cookies.
ERR_TOO_MANY_REDIRECTS
==== ADDITIONAL INFO ====
This middleware gets kicked off here:
const getApplicationRef = (req, res) => {
req.session.accessPage = '/decision/application-reference';
res.render('pages/application-reference', { appRef: req.session.appRef });
};
which invokes:
const express = require('express');
const router = express.Router();
const { getApplicationRef, submitApplicationRef } = require('../../services/handler/application/application-ref-handler');
router.get('/', getApplicationRef);
router.post('/', submitApplicationRef);
module.exports = router;
getApplicationRef =
const getApplicationRef = (req, res) => {
req.session.accessPage = '/decision/application-reference';
res.render('pages/application-reference', { appRef: req.session.appRef });
};
And here's some code that renders the page properly:
const getSecurityCode = (req, res) => {
if (req.session.appRef) {
req.session.accessPage = '/decision/security-code';
res.render('pages/security-code', { secCode: req.session.secCode });
} else {
res.redirect('/decision/session-ended');
}
};

First off, the code you've shown in your question contains no nunjucks code at all so it's hard to see where you expect things to be using nunjucks. You aren't showing us very much specifics in your code so we can just offer the general advice.
If you want nunjucks to render the page, you need to call res.render("yourtemplate"), not res.sendFile(somefile) and you need to have properly registered nunjucks as your template engine.
If you're using res.redirect('/decision/session-ended');, then you need a route for /decision/session-ended that calls res.render() appropriately and does NOT do further redirecting and you need to make sure that route is not redirected by your middleware (probably just by placing that route handler before your middleware).
For more detail, please show the entire code flow that is relevant here from when the session ends to all requests involved in that.

Related

Nodejs Express - return 405 for un-supported method

I'm running a standard NodeJs 8 with Express and currently when a request for an existing path but un-supported method comes in, Express return 404.
For example 'POST /login' is supported, but 'GET /login' is not, but it returns 404.
How can I make Express return 405 in such a case?
Here's the routes file:
const express = require('express');
const router = express.Router();
const loginController = require('../controllers/login');
router.route('/login').post(loginController.loginUser);
module.exports = router;
Please advise.
You can simply add the .all() handler to your route chain, like so:
const methodNotAllowed = (req, res, next) => res.status(405).send();
router
.route(`/login`)
.post(loginController.loginUser)
.all(methodNotAllowed);
Explanation
This works because requests are passed to the handlers in the order they are attached to the route (the request "waterfall"). The .post() handler will catch your POST requests, and the rest will fall through to the .all() handler.
Also see this question for more details.
Authenticating all POST routes
If you would like to ensure that the user is logged in for all POST requests, but return a 405 response for any other requests, you can use a regular expression to match all routes with router.post('*'), like so:
router
.post(`*`, loginController.loginUser)
.all(methodNotAllowed);
The problem with this approach, however, is that no 404 errors will ever be returned to the client, only 405. Therefore I recommend attaching the methodNotAllowed handler to each individual route, like in the first code snippet above. This approach will return 404 errors for routes that don't exist, but 405 errors for routes that do.
Determining the available methods for a route
To determine which methods are allowed for a route, use router.stack:
app.use((req, res, next) => {
const methods = router.stack
// Filter for the route that matches the currently matched route
.filter(layer => layer.route.path === req.path)[0]
.route
.methods;
if (!methods[req.method]) methodNotAllowed(req, res, next);
else next();
});
You can try this that way:
app.route("/login")
.get((req, res) => {
/* HANDLE GET */
})
.post((req, res) => {
/* HANDLE POST */
})
.all((req, res) => {
res.status(405).send();
});
How it works?
If request matches the route. It will go through the handlers. If a handler is present, it will be handled using that specific one. Otherwise, it will reach the 'all' handler that will set the status code to 405 and send the response.
Here You can find the discussion about it:
405 issue
#You question below:
You can try that way:
loginRoutes.js content:
const router = require('express').Router();
router.route('/')
.get((req, res) => {
res.status(200).send()
})
module.exports = router
server file content:
const express = require('express')
const app = express();
const router = express.Router();
const loginRoutes = require('./loginRoutes')
const PORT = process.env.PORT || 8080;
router.use('/login', loginRoutes)
router.route('/login').all((req, res) => { res.status(405).send() })
app.use(router);
app.listen(PORT, () => console.log(`started on port: ${PORT}`))
You can use this snippet of code to automatically send 405 status code when route from the same path exist but not with the current method
app.use(function (req, res, next) {
const AllLayers = app._router.stack
const Layers = AllLayers.filter(x => x.name === 'bound dispatch' && x.regexp.test(req.path))
const Methods = [];
Layers.forEach(layer => {
for (let method in layer.route.methods) {
if (layer.route.methods[method] === true) {
Methods.push(method.toUpperCase());
}
}
})
if (Layers.length !== 0 && !Methods.includes(req.method)) {
res.setHeader('Allow', Methods.join(','))
if (req.method === "OPTIONS") {
return res.send(Methods.join(', '))
}
else {
return res.sendStatus(405);
}
}
else {
next();
}
});
Hope this could be helpfull to someone
If you want to determine what methods COULD have been used you need to do a lot of digging in the app function you start your server with, and through some string manipulation and the like you can figure out what the possible methods are and return them in the error. If you're interested in how its done check out https://github.com/Justinlkirk/express-ez-405 or just use the npm package here https://www.npmjs.com/package/express-ez-405

how to render html page in loopback

hello guys i m new to loopback, can anyone help me with this following things
when we install loopback by default we have client folder when we can place all our front end file now place all html file there and render these html file from router for eg ;-
var router = server.loopback.Router();
router.get('/', function(req, res) {
res.render('index');
});
router.get('/login', function(req, res) {
res.render('login');
});
i want something like this i have index,login html file in client folder so how i can do that i does lots of google but haven't find any soultion like this
Assuming you created your project via loopback's CLI, you should have a server/boot/root.js file.
'use strict';
module.exports = function(server) {
// Install a `/` route that returns server status
var router = server.loopback.Router();
router.get('/', server.loopback.status());
server.use(router);
};
Either remove or change the route to server.loopback.status() (e.g. router.get('/status', server.loopback.status()).
In server/middleware.json, you should see a line near the bottom with "files": {},.
Modify it to the following:
"files": {
"loopback#static": {
"params": "$!../client"
}
},
Place all your static files into the client directory.
This is from loopback's documentation: Add a static web page. I'd recommend going through all the Getting started with LoopBack documentation if you are new.
Just posting the answer so that it may work for the people for whom the Previous answer din work, I would like to suggest some other approach that worked for me.
inside server/boot/root.js file add the below code:
'use strict';
const path = require('path');
module.exports = function(server) {
// Install a `/` route that returns server status
const router = server.loopback.Router();
router.get('/', (req, res, next) => {
res.sendFile(path.join(__dirname,'./../../client','index.html'));
});
server.use(router);
};

In express how do I redirect a user to an external url?

I have a payment system using node.js and braintree, when the payment is successful I want to send the user to the back end. My back end is setup elsewhere.
I have tried
res.writeHead(301,
{Location: 'http://app.example.io'}
);
res.end();
So window.location is obviously not available. I cant think of any ways to redirect a user?
You can do
res.redirect('https://app.example.io');
Express docs: https://expressjs.com/en/api.html#res.redirect
The selected answer did not work for me. It was redirecting me to: locahost:8080/www.google.com - which is nonsense.
301 Moved Permanently needs to be included with res.status(301) as seen below.
app.get("/where", (req, res) => {
res.status(301).redirect("https://www.google.com")
})
You are in the same situation since your back-end is elsewhere.
app.get("/where", (req, res) => {
res.status(301).redirect("https://www.google.com")
})
You need to include the status (301)
I just have the same issue and got it work by adding "next". I use routers so maybe you have same issue as mine? Without next, i got error about no render engine...weird
var express = require('express');
var router = express.Router();
var debug = require('debug')('node_blog:server');
/* GET home page. */
router.get('/', function(req, res, next) {
debug("index debug");
res.render('index.html', { title: 'Express' });
});
router.post("/", function (req, res, next) {
//var pass = req.body("password");
//var loginx = req.body("login");
//res.render('index.html', { title: 'Express' });
res.redirect("/users")
next
});
module.exports = router;
None of these worked for me, so I tricked the receiving client with the following result:
res.status(200).send('<script>window.location.href="https://your external ref"</script>');
Some will say if noscript is on this does not work, but really which site does not use it.

How do I redirect in expressjs while passing some context?

I am using express to make a web app in node.js. This is a simplification of what I have:
var express = require('express');
var jade = require('jade');
var http = require("http");
var app = express();
var server = http.createServer(app);
app.get('/', function(req, res) {
// Prepare the context
res.render('home.jade', context);
});
app.post('/category', function(req, res) {
// Process the data received in req.body
res.redirect('/');
});
My problem is the following:
If I find that the data sent in /category doesn't validate, I would like pass some additional context to the / page. How could I do this? Redirect doesn't seem to allow any kind of extra parameter.
There are a few ways of passing data around to different routes. The most correct answer is, of course, query strings. You'll need to ensure that the values are properly encodeURIComponent and decodeURIComponent.
app.get('/category', function(req, res) {
var string = encodeURIComponent('something that would break');
res.redirect('/?valid=' + string);
});
You can snag that in your other route by getting the parameters sent by using req.query.
app.get('/', function(req, res) {
var passedVariable = req.query.valid;
// Do something with variable
});
For more dynamic way you can use the url core module to generate the query string for you:
const url = require('url');
app.get('/category', function(req, res) {
res.redirect(url.format({
pathname:"/",
query: {
"a": 1,
"b": 2,
"valid":"your string here"
}
}));
});
So if you want to redirect all req query string variables you can simply do
res.redirect(url.format({
pathname:"/",
query:req.query,
});
});
And if you are using Node >= 7.x you can also use the querystring core module
const querystring = require('querystring');
app.get('/category', function(req, res) {
const query = querystring.stringify({
"a": 1,
"b": 2,
"valid":"your string here"
});
res.redirect('/?' + query);
});
Another way of doing it is by setting something up in the session. You can read how to set it up here, but to set and access variables is something like this:
app.get('/category', function(req, res) {
req.session.valid = true;
res.redirect('/');
});
And later on after the redirect...
app.get('/', function(req, res) {
var passedVariable = req.session.valid;
req.session.valid = null; // resets session variable
// Do something
});
There is also the option of using an old feature of Express, req.flash. Doing so in newer versions of Express will require you to use another library. Essentially it allows you to set up variables that will show up and reset the next time you go to a page. It's handy for showing errors to users, but again it's been removed by default. EDIT: Found a library that adds this functionality.
Hopefully that will give you a general idea how to pass information around in an Express application.
The easiest way I have found to pass data between routeHandlers to use next() no need to mess with redirect or sessions.
Optionally you could just call your homeCtrl(req,res) instead of next() and just pass the req and res
var express = require('express');
var jade = require('jade');
var http = require("http");
var app = express();
var server = http.createServer(app);
/////////////
// Routing //
/////////////
// Move route middleware into named
// functions
function homeCtrl(req, res) {
// Prepare the context
var context = req.dataProcessed;
res.render('home.jade', context);
}
function categoryCtrl(req, res, next) {
// Process the data received in req.body
// instead of res.redirect('/');
req.dataProcessed = somethingYouDid;
return next();
// optionally - Same effect
// accept no need to define homeCtrl
// as the last piece of middleware
// return homeCtrl(req, res, next);
}
app.get('/', homeCtrl);
app.post('/category', categoryCtrl, homeCtrl);
I had to find another solution because none of the provided solutions actually met my requirements, for the following reasons:
Query strings: You may not want to use query strings because the URLs could be shared by your users, and sometimes the query parameters do not make sense for a different user. For example, an error such as ?error=sessionExpired should never be displayed to another user by accident.
req.session: You may not want to use req.session because you need the express-session dependency for this, which includes setting up a session store (such as MongoDB), which you may not need at all, or maybe you are already using a custom session store solution.
next(): You may not want to use next() or next("router") because this essentially just renders your new page under the original URL, it's not really a redirect to the new URL, more like a forward/rewrite, which may not be acceptable.
So this is my fourth solution that doesn't suffer from any of the previous issues. Basically it involves using a temporary cookie, for which you will have to first install cookie-parser. Obviously this means it will only work where cookies are enabled, and with a limited amount of data.
Implementation example:
var cookieParser = require("cookie-parser");
app.use(cookieParser());
app.get("/", function(req, res) {
var context = req.cookies["context"];
res.clearCookie("context", { httpOnly: true });
res.render("home.jade", context); // Here context is just a string, you will have to provide a valid context for your template engine
});
app.post("/category", function(req, res) {
res.cookie("context", "myContext", { httpOnly: true });
res.redirect("/");
}
use app.set & app.get
Setting data
router.get(
"/facebook/callback",
passport.authenticate("facebook"),
(req, res) => {
req.app.set('user', res.req.user)
return res.redirect("/sign");
}
);
Getting data
router.get("/sign", (req, res) => {
console.log('sign', req.app.get('user'))
});
we can use express-session to send the required data
when you initialise the app
const express = require('express');
const app = express();
const session = require('express-session');
app.use(session({secret: 'mySecret', resave: false, saveUninitialized: false}));
so before redirection just save the context for the session
app.post('/category', function(req, res) {
// add your context here
req.session.context ='your context here' ;
res.redirect('/');
});
Now you can get the context anywhere for the session. it can get just by req.session.context
app.get('/', function(req, res) {
// So prepare the context
var context=req.session.context;
res.render('home.jade', context);
});
Here s what I suggest without using any other dependency , just node and express, use app.locals, here s an example :
app.get("/", function(req, res) {
var context = req.app.locals.specialContext;
req.app.locals.specialContext = null;
res.render("home.jade", context);
// or if you are using ejs
res.render("home", {context: context});
});
function middleware(req, res, next) {
req.app.locals.specialContext = * your context goes here *
res.redirect("/");
}
You can pass small bits of key/value pair data via the query string:
res.redirect('/?error=denied');
And javascript on the home page can access that and adjust its behavior accordingly.
Note that if you don't mind /category staying as the URL in the browser address bar, you can just render directly instead of redirecting. IMHO many times people use redirects because older web frameworks made directly responding difficult, but it's easy in express:
app.post('/category', function(req, res) {
// Process the data received in req.body
res.render('home.jade', {error: 'denied'});
});
As #Dropped.on.Caprica commented, using AJAX eliminates the URL changing concern.
Update 2021:
i tried url.format and querystring and both of them are deprecated, instead we can use URLSearchParams
const {URLSearchParams} = require('url')
app.get('/category', (req, res) =>{
const pathname = '/?'
const components ={
a:"a",
b:"b"
}
const urlParameters = new URLSearchParams(components)
res.redirect(pathname + urlParameters)
})
I use a very simple but efficient technique
in my app.js ( my entry point )
I define a variable like
let authUser = {};
Then I assign to it from my route page ( like after successful login )
authUser = matchedUser
It May be not the best approach but it fits my needs.
app.get('/category', function(req, res) {
var string = query
res.redirect('/?valid=' + string);
});
in the ejs you can directly use valid:
<% var k = valid %>

Using routes in Express-js

So I'm starting to use Node.js. I saw the video with Ryan Dahl on Nodejs.org and heard he recommended Express-js for websites.
I downloaded the latest version of Express, and began to code. I have a fully fledged static view up on /, but as soon as I try sending parameters, I get errors like this:
Cannot GET /wiki
I tried following the guide on expressjs.com but the way one uses routes has changed in the latest version, which makes the guide unusable.
Guide:
app.get('/users/:id?', function(req, res, next){
var id = req.params.id;
if (id) {
// do something
} else {
next();
}
});
Generated by Express:
app.get('/', routes.index);
My problem arises when I try and add another route.
app.get('/wiki', routes.wiki_show);
I've tried a bunch of approaches, but I keep getting the Cannot GET /wiki (404) error.
routes/index.js looks like this:
exports.index = function(req, res) {
res.render('index', { title: 'Test', articles: articles, current_article: current_article, sections: sections })
};
The only thing I did there was add some parameters (arrays in the same file) and this i working. But when I copy the contents and change exports.index to exports.wiki or exports.wiki_show I still get the Cannot GET /wiki error.
Can anyone explain to me what I'm missing here? - Thanks.
So, after I created my question, I got this related list on the right with a similar issue: Organize routes in Node.js.
The answer in that post linked to the Express repo on GitHub and suggests to look at the 'route-separation' example.
This helped me change my code, and I now have it working. - Thanks for your comments.
My implementation ended up looking like this;
I require my routes in the app.js:
var express = require('express')
, site = require('./site')
, wiki = require('./wiki');
And I add my routes like this:
app.get('/', site.index);
app.get('/wiki/:id', wiki.show);
app.get('/wiki/:id/edit', wiki.edit);
I have two files called wiki.js and site.js in the root of my app, containing this:
exports.edit = function(req, res) {
var wiki_entry = req.params.id;
res.render('wiki/edit', {
title: 'Editing Wiki',
wiki: wiki_entry
})
}
The route-map express example matches url paths with objects which in turn matches http verbs with functions. This lays the routing out in a tree, which is concise and easy to read. The apps's entities are also written as objects with the functions as enclosed methods.
var express = require('../../lib/express')
, verbose = process.env.NODE_ENV != 'test'
, app = module.exports = express();
app.map = function(a, route){
route = route || '';
for (var key in a) {
switch (typeof a[key]) {
// { '/path': { ... }}
case 'object':
app.map(a[key], route + key);
break;
// get: function(){ ... }
case 'function':
if (verbose) console.log('%s %s', key, route);
app[key](route, a[key]);
break;
}
}
};
var users = {
list: function(req, res){
res.send('user list');
},
get: function(req, res){
res.send('user ' + req.params.uid);
},
del: function(req, res){
res.send('delete users');
}
};
var pets = {
list: function(req, res){
res.send('user ' + req.params.uid + '\'s pets');
},
del: function(req, res){
res.send('delete ' + req.params.uid + '\'s pet ' + req.params.pid);
}
};
app.map({
'/users': {
get: users.list,
del: users.del,
'/:uid': {
get: users.get,
'/pets': {
get: pets.list,
'/:pid': {
del: pets.del
}
}
}
}
});
app.listen(3000);
Seems that only index.js get loaded when you require("./routes") .
I used the following code in index.js to load the rest of the routes:
var fs = require('fs')
, path = require('path');
fs.readdirSync(__dirname).forEach(function(file){
var route_fname = __dirname + '/' + file;
var route_name = path.basename(route_fname, '.js');
if(route_name !== 'index' && route_name[0] !== "."){
exports[route_name] = require(route_fname)[route_name];
}
});
You could also organise them into modules. So it would be something like.
./
controllers
index.js
indexController.js
app.js
and then in the indexController.js of the controllers export your controllers.
//indexController.js
module.exports = function(){
//do some set up
var self = {
indexAction : function (req,res){
//do your thing
}
return self;
};
then in index.js of controllers dir
exports.indexController = require("./indexController");
and finally in app.js
var controllers = require("./controllers");
app.get("/",controllers.indexController().indexAction);
I think this approach allows for clearer seperation and also you can configure your controllers by passing perhaps a db connection in.
No one should ever have to keep writing app.use('/someRoute', require('someFile')) until it forms a heap of code.
It just doesn't make sense at all to be spending time invoking/defining routings. Even if you do need custom control, it's probably only for some of the time, and for the most bit you want to be able to just create a standard file structure of routings and have a module do it automatically.
Try Route Magic
As you scale your app, the routing invocations will start to form a giant heap of code that serves no purpose. You want to do just 2 lines of code to handle all the app.use routing invocations with Route Magic like this:
const magic = require('express-routemagic')
magic.use(app, __dirname, '[your route directory]')
For those you want to handle manually, just don't use pass the directory to Magic.

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