is it possible to name routes in Express.js - node.js

Basic route is like this:
app.get('/', function(req, res){
res.send('hello world');
});
Is it possible to name that route and have it available in any template so it can be used like this:
app.get('/', name="index", function(req, res){
res.send('hello world');
});
Go to site index page.
Inspiration comes from Django :)

There is no out of the box mechanism for that. However you can mimic Django's style like that: define urls.js file which will hold an array of URLs. First start with:
myviews.js
exports.Index = function( req, res, next ) {
res.send( "hello world!" );
};
urls.js
var MyViews = require( "mywviews.js" );
module.exports = [
{ name : "index", pattern : "/", view : MyViews.Index }
]
Now in app.js ( or whatever the main file is ) you need to bind urls to Express. For example like this:
app.js
var urls = require( "urls.js" );
for ( var i = 0, l = urls.length; i < l; i++ ) {
var url = urls[ i ];
app.all( url.pattern, url.view );
};
Now you can define custom helper ( Express 3.0 style ):
var urls = require( "urls.js" ), l = urls.length;
app.locals.url = function( name ) {
for ( var i = 0; i < l; i++ ) {
var url = urls[ i ];
if ( url.name === name ) {
return url.pattern;
}
};
};
and you can easily use it in your template. Now the problem is that it does not give you fancy URL creation mechanism like in Django ( where you can pass additional parameters to url ). On the other hand you can modify url function and extend it. I don't want to go into all details here, but here's an example how to use regular expressions ( you should be able to combine these to ideas together ):
Express JS reverse URL route (Django style)
Note that I posted the question, so I had the same problem some time ago. :D

I found express-reverse to nicely solve this issue
https://github.com/dizlexik/express-reverse
It augments the standard routing allowing you to pass the route's name as first argument
app.get('test', '/hello/:x', function(req, res, next) {
res.end('hello ' + req.params.x);
});
Let you build the url from inside a template by name
Test
Let you redirect to an url by name
app.get('/test-redirect', function(req, res, next) {
res.redirectToRoute('test', { x: 'world' });
});

Another option that I don't see here is to just extract the route function out with a function name. If all you are trying to do is writing self-documenting code.
function updateToDo(req, res, next) { /*do router stuff*/};
router.put('/', updateToDo);

I had the same problem and decided to make a library to help me out.
Besides not hardcoding your routes, it allows me to build navigation components like breadcrumbs and I can use it server side with express or client side with Backbone or whatever.
https://github.com/hrajchert/express-shared-routes

I thing this is what you are looking for: Named routes
Example code:
var express = require('express');
var app = express();
var Router = require('named-routes');
var router = new Router();
router.extendExpress(app);
router.registerAppHelpers(app);
app.get('/admin/user/:id', 'admin.user.edit', function(req, res, next){
// for POST, PUT, DELETE, etc. replace 'get' with 'post', 'put', 'delete', etc.
//... implementation
// the names can also be accessed here:
var url = app.namedRoutes.build('admin.user.edit', {id: 2}); // /admin/user/2
// the name of the current route can be found at req.route.name
});
app.listen(3000);
As you can see you can name the route as admin.user.edit and access it in you views

Check this Gist please
var env="http://localhost:3000/"
var route='users/:id/profile/'
var routes=[
{
'name':'profile',
'path':'users/:id/:profile/'
}
]
function RouteName(route,arg){
let targetRoute = routes.find(e=>e.name==route).path
for(var key in arg){
targetRoute=targetRoute.replace(`:${key}`,arg[key])
//console.log(targetRoute)
}
return targetRoute
}
console.log(env+RouteName('profile',{'id':3,'profile':'loaiabdalslam'}))

Related

How to pass variable from app.js to routes/index.js?

I'm using shrinkroute https://npmjs.org/package/shrinkroute to make links in nodejs. I get error 500 ReferenceError: shrinkr is not defined
How to pass shrinkroute to routes/index.js? Is there a better way to create url by passing query string args?
//app.js
var app = express();
var shrinkr = shrinkroute( app, {
"user": {
path: "/user/:id?",
get: routes.showOrListUsers
}
});
//url method works in app.js
var url = shrinkr.url( "user", { id: 5, page:40, type:'a' } );
console.log(url);
app.use( shrinkr.middleware );
//routes/index.js
exports.showOrListUsers = function(req, res, next) {
console.log(req.params);
//shrinkr errors out in index.js
var url2 = shrinkr.url( "users", {name: "foo"});
console.log(url2);
}
One solution would be to store shrinkr in your app object using app.set:
// app.js
...
app.set('shrinkr', shrinkr);
...
In routes/index.js, you can access it through the req.app or res.app objects:
exports.showOrListUsers = function(req, res, next) {
var shrinkr = req.app.get('shrinkr');
...
};
A bit late to the party, but the following works as well:
app.js
var my_var = 'your variable';
var route = require('./routes/index')(my_var);
app.get('/', route);
and meanwhile in route.js
var express = require('express')
, router = express.Router()
// Router functions here, as normal; each of these
// run only on requests to the server
router.get('/', function (req, res, next) {
res.status(200).end('Howdy');
});
module.exports = function(my_var){
// do as you wish
// this runs in background, not on each
// request
return router;
}
Two easy ways to achieve what you want:
1. Accessing your shrinkroute instance from within your route
Simple as that. Nothing else is required after Shrinkroute is setup.
exports.showOrListUsers = function(req, res, next) {
var shrinkr = req.app.shrinkroute;
console.log( "Route: " + req.route.name ); // ta-da, made available by Shrinkroute
// do your URL buildings
};
2. Using the middleware
If you don't want be tempted with non URL building methods of Shrinkroute, you can use the middleware, which will make available to you some helpers in your route and in your template (via locals):
// app.js
app.use( shrinkr.middleware );
// routes/index.js
exports.showOrListUsers = function(req, res, next) {
console.log( "Route: " + req.route.name ); // ta-da, made available by Shrinkroute
req.buildUrl( "users", { name: "foo" } );
// or, if you want the full url with the scheme and host...
req.buildFullUrl( "users", { name: "foo" } );
};
And maybe you want to use them in your templates as well?
// templates/index.jade
a( href=url( "users", { name: "foo" } ) ) Foo profile
a( href=fullUrl( "users", { name: "foo" } ) ) Foo profile
This method has the advantage that you don't get direct access to route setters inside a route.
Disclaimer: I'm the author of Shrinkroute.
you should import it. add following line to the very beginning of your code
var shrinkroute = require('shrinkroute');

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 %>

Calling already defined routes in other routes in Express NodeJS

I am writing a web app in node.js using Express. I have defined a route as follows:
app.get("/firstService/:query", function(req,res){
//trivial example
var html = "<html><body></body></html>";
res.end(html)
});
How do I reuse that route from within express?
app.get("/secondService/:query", function(req,res){
var data = app.call("/firstService/"+query);
//do something with the data
res.end(data);
});
I couldn't find anything in the API documentation and would rather not use another library like "request" because that seems kludgey. I am trying to keep my app as modular as possible. Thoughts?
Thanks
Similar to what Gates said, but I would keep the function(req, res){} in your routes file. So I would do something like this instead:
routes.js
var myModule = require('myModule');
app.get("/firstService/:query", function(req,res){
var html = myModule.firstService(req.params.query);
res.end(html)
});
app.get("/secondService/:query", function(req,res){
var data = myModule.secondService(req.params.query);
res.end(data);
});
And then in your module have your logic split up like so:
myModule.js
var MyModule = function() {
var firstService= function(queryParam) {
var html = "<html><body></body></html>";
return html;
}
var secondService= function(queryParam) {
var data = firstService(queryParam);
// do something with the data
return data;
}
return {
firstService: firstService
,secondService: secondService
}
}();
module.exports = MyModule;
Can you simply break this out into another function, put it in a shared spot and go from there?
var queryHandler = require('special_query_handler');
// contains a method called firstService(req, res);
app.get('/firstService/:query', queryHandler.firstService);
// second app
app.get('/secondService/:query', queryHandler.secondService);
Honestly, this whole business of nesting the call back inside of the app.get(...) is not really a great practice. You end up with a giant file containing all of the core code.
What you really want is a file filled with app.get() and app.post() statements with all of the callback handlers living in different, better organized files.
If you have a lot of middleware on your route, you can benefit from spreading:
const router = express.Router();
const myMiddleware = [
authenticationMiddleware(),
validityCheckMiddleware(),
myActualRequestHandler
];
router.get( "/foo", ...myMiddleware );
router.get( "/v1/foo", ...myMiddleware );
You can use run-middleware module exactly for that
app.runMiddleware('/firstService/query',function(responseCode,body,headers){
// Your code here
})
More info:
Module page in Github & NPM;
Examples of use run-middleware module
Disclosure: I am the maintainer & first developer of this module.
I have used following way:
at userpage.js
router.createSitemap = function(req, res, callback) { code here callback(value); }
at product.js
var userPageRouter = require('userpages');
userPageRouter.createSitemap(req, res, function () {
//console.log('sitemap');
});
Also can use in same userpage.js router I can use for other routing as well. eg.
router.get('/sitemap', function (req, res, next) {
router.createSitemap(req, res, function () {
res.redirect('/sitemap.xml');
}); });
Hope this will help.

Using dynamicHelpers in routes setup with Express and node.js

I began using node.js+express combo very recently and I stumbled at a need to use dynamicHelpers not only in my views but also inside my routes setup (routes/index.js in default express config). Should I use some different pattern?
app.js
app.dynamicHelpers({
translate : function(req, res) {
return translate;
},
language : function(req, res) {
return req.session.language || "en";
},
});
Below I would like to have a convenient access to whatever I set for my dynamicHelpers because in my mind it is the same context .. so why set it up two times?
var routes = {};
routes.index = function(req, res) {
res.render('index', {
title : 'My webpage',
categories : categoryPositions,
referrer : req.header("Referrer"),
languages : ["pl", "en", "de"],
<----- here I would like to use my dynamicHelpers (for example translate)
})
};
I know I can pass my data in many ways but I do not want to repeat my code
and want to set up the common context only once and as cleanly as polssible. I welcome any criticism and good advice!
functions.js
module.exports = {
translate : function(req, res) {
return translate;
},
language : function(req, res) {
return req.session.language || "en";
},
};
helpers.js
var functions = require('./functions');
app.dynamicHelpers({
translate : functions.translate,
language : functions.language
});
Depending on what you need you can also write the helpers like this
var functions = require('./functions');
app.dynamicHelpers( functions );
routes.js
var functions = require('./functions');
var routes = {
index: function(req, res) {
res.render('index', {
title : 'My webpage',
categories : categoryPositions,
referrer : req.header("Referrer"),
languages : ["pl", "en", "de"],
stuff: functions.translate(req, res) // <----- here I would like to use my dynamicHelpers (for example translate)
})
}
};
So actually the solution is to use not yet released express 3.0, modify:
npm install -g express#3.0
Follow https://github.com/visionmedia/express/wiki/Migrating-from-2.x-to-3.x , http://www.devthought.com/code/use-jade-blocks-not-layouts/
The new express simplified dynamicHelpers to the use of res.locals which are both available in the routes setup and then bound to the view.
Example:
// app.
app.locals.use(function(req, res) {
var language = req.session.language || "en";
res.locals.language = language;
res.locals.translate = function(clause) {
return translate(clause, language);
};
});
In the routes setup I can now access both res.locals.language and res.locals.translate.
In my views I simply can use translate('something').

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.

Resources