Is it possible to access my query params in my views in ExpressJS 3?
I have a url: http://example.com?search=blah
And in my view I would like to access the search param
I can pass it as a locals but wondering if I can access it directly - my experiments were not successful.
Not looking for the pros and cons of direct access - just want to know if it's possible and how.
Here are a few ways to access req.query from your view:
Set it as a local in the call to render
function(req, res) {
res.render('myview', {query: req.query});
};
in your view you can access search as query.search.
Set res.locals
function(req, res) {
res.locals.query = req.query;
res.render('myview');
};
in your view you can access search as query.search.
Use middleware
This is similar to the previous example but we can use middleware in a reusable way.
function(req, res, next) {
res.locals.query = req.query;
next();
};
Any route that uses the above middleware, will have res.locals.query set.
edit
It appears that I misunderstood the question. The intent was to see if the request data could be accessed without use of the above techniques. As far as I know, it can not. Hopefully the above will still be useful for some readers.
I am pretty sure only locals get passed to the view.
Not looking for the pros and cons of direct access - just want to know if it's possible and how.
There are no pros and cons. It's like saying I want to multiply 15 with 0 but I don't want the answer to be apple.
middleware:
function(req, res, next) {
res.locals.param = req.param;
next();
};
view:
<%= param.search %>
Related
Does any one knows an example or could explain here how node.js and express would have to route for a multilanguage site? I'm using i18n-node for translation and folder like routing ( /es/, /de/ , etc ) for different languages. This all are static routes but I also have routes like apiRoutes.route('/user/profile') using 'app' at the begining ( app.get('/app/user/profile') so please consider this in your answer so is NOT necesary route to : app.get('/es/app/user/profile') .
having 15 routes like this now:
app.get('/terms', function(req, res) {
res.render('terms',{
...
});
});
how it have to be set for routes like:
app.get('/es/terms', function(req, res) {
res.render('terms',{
...
});
});
Should I duplicate this routes and add for example a locale for
each like:
app.get('/es/terms', function(req, res) {
res.render('terms',{
...
});
});
Or Should do something like:
if cookie['lang'] && cookie['lang'] is in locales
// then redirect to /:lang/terms
else
// show default language in /terms
if req.headers["accept-language"] && req.headers["accept-language"]
// then redirect to /:lang/terms
else
//show default language in /terms
Or there is another way I should approach this that follows good practices or is better respecting standards?
Miro's Answer in :
How can I get the browser language in node.js (express.js)? says I should use app.all('*', ...
Is this all I need?, ..still, it might have a syntax error or i'm not understanding well this two parts
var rxLocal = /^\/(de|en)/i;
...
app.get(/\/(de|en)\/login/i, routes.login);
thanks in advance
You need to consider 2 things :
1. How get the local :
Accept-Language
The HTTP protocole define the Accept-Language header to manage the local. This is a normalized method. You can access it with the req.acceptsLanguages method of express.
+Normalized
+Natively support by brower
-Not easy to by passe by the end user
Path / Cookies
You can get the local from the path. In express it can be do with a parameter patter like /:local/rest/of/path and retrieve in the request object with the req.param method.
You can also get the information from the cookies with the req.cookies properties (don't forgot to set it).
Both
To increase the user experience you can mix the both method. For exemple get the default language from the HTTP header send by the browser but permite to the user to override this in you application and store this parameter in the cookies.
2. Use the local:
Each methods to get the local can be used from different way. I will
use random of them in exemple but they are all compatible.
Top level configuration.
In case of you use a template Engine and you controller can be local agnostic. You can use a middleware to get the local information and configure the render engine.
app.use('/:local' (req, res, next) => {
let localKey = req.param('local');
res.locals = // Some ingenious method to get the locales from localKey
next();
}
Check res.locals and your engine documentation.
Use it in controller.
If the local is part of the contoller process. You can get directly is value in controller.
In case of you use a complexe method to determine the final value of the local, you can also use a middleware to determine this value and enrich the request with it.
app.use((req, res, next) => {
let local = req.cookies.local;
if(!local) local = req.acceptsLanguages();
if(!local) local = 'en-US';
req.local = local;
}
Both
You can use both method too. It depend of what you need. Find the best way to get a maintainable code and avoid replication for your use case.
When you use middle where witch impact the controllers, be sure you declare them before your routes.
You can use a route parameter to get the locale from the URL, like this:
app.get('/:lang/terms', function (req, res) {
if (req.params === 'es') {
res.send('¡Hola!');
else {
res.send('Hi!');
}
});
The colon character tells Express to put whatever is between the first to slashes of the path in req.params.lang.
See express routing documentation for details.
In my express application I have a module called helpers thats is required in almost all my routes and modules. This module has a logger method that logs to fluentd (but that's unimportant). While building the data to log I'd like to add a unique identifier of the request, so that all the logs written for the same request have the same unique ID. Using a global var in the app entry point app.use doesn't work because this var would be overwritten every time a new request hits, so the global uuid will change would obviously change in case of high load or long running tasks. The res.locals is not available outside routing, so I can't use it for this matter. Is there a way to create a var that would be unique per request and available in every module or maybe a way to access the res.locals data outside routing? Thank you
EDIT
Maybe an example will help understand better the question.
Suppose I have a module called helpers.js like this:
let helpers = {};
helpers.log = (logData, logName) => {
fluentLogger.emit('', {
name: logName,
//uuid: the needed uuid,
message: logData
});
}
module.exports = helpers;
Now obviously I can do this in my app.js entry point:
app.use(function (req, res, next) {
res.locals.uuid = uuid.v4();
next();
});
and then in every loaded middleware module that requires helpers(adding a new param to the helpers.log method):
const helpers = require('helpers');
router.post('/', (req, res, next) => {
helpers.log('my log message', 'myLogName', res.locals.uuid);
next();
});
and this will normally work. But suppose a big or middle size project where there are hundreds of custom modules and models (not middlewares) and a module may require other modules that require other modules that require finally the helpers module. In this case I should pass the res.locals.uuid as a parameter to every method of every method so that I have it available in the logger method. Not a very good idea. Suppose I have a new module called dbmodel.js that is required in a middleware function:
const helpers = require('helpers');
let dbmodel = {};
dbmodel.getSomeData = (someParam) => {
//some logic
helpers.log('my log message', 'myLogName');
}
module.exports = dbmodel;
The dbmodel has no idea about the res.locals data if I don't pass it from the middleware, so the helpers.log method will also have no idea about this.
In PHP one would normally write a GLOBAL var in the application's entry point so a hypothetical logger function would have access to this global on every method request from whichever class of the application.
Hope this explanation will help :) Thank you
EDIT 2
The solution for this kind of problems is CLS. Thanks to #robertklep for the hint. A good slideshare explaining exactly the same problem (logger with unique ID) and explaining the CLS solutions can be found here: https://www.slideshare.net/isharabash/cls-and-asynclistener
I answered a very similar question here which will solve this problem.
I used to solve the problem the libraries node-uuid and continuation-local-storage. Take a look to the answer of this question and see if it helps:
NodeJS Express - Global Unique Request Id
And you want a bigger explanation, take a look here:
Express.js: Logging info with global unique request ID – Node.js
Yes you can do so by one method .
Every request comes to his routes pass that request inside the middleware.
Suppose you have
app.get('/', function(req, res) {
res.sendFile(path.join(public + "index.html"));
});
a request.
Place Middleware in it .and edit req field coming , in this way you will get the unique variable values for each request
check out this .
https://expressjs.com/en/guide/writing-middleware.html
Like this
var requestTime = function (req, res, next) {
req.requestTime = Date.now()
next()
}
app.use(requestTime)
app.get('/', function (req, res) {
var responseText = 'Hello World!<br>'
responseText += '<small>Requested at: ' + req.requestTime + '</small>'
res.send(responseText)
})
Here req.requestTime is unique for each request.
what is difference between below two code block in Node.JS (express + ejs)?
res.render('demo', {locals:{"variable":data}});
AND
res.render('demo', {"variable":data});
When to use which one? can any one please help me out in this.
The correct way of passing variables to the view is the wollowing
res.render('demo', {"variable":data});
Then you have an objet res.locals Which you can append data and it will be passed to the view.
For example if you have a middlewere for the authentication, you can set the auth variables even before the request arrives in your route.
app.use(function(req, res, next){
res.locals.user = req.user;
res.locals.authenticated = ! req.user.anonymous;
next();
});
I'm implementing a RESTful API with Express in Node, and I'm new to both. I'd like to use basic authentication to control access.
I would like to apply it using something like a whitelist but I'm not sure how to do that.
Blacklisting is easy, I can just pepper my #VERB calls with the second argument:
app.get('/', asyncAuth, requestHandler);
I can take that even further and blacklist everything with:
app.all('*', asyncAuth, requestHandler);
But I want to apply my basicAuth to every single route, except for POST /users. Is there an elegant way to do that? Can I use the 'blacklist' approach then selectively remove it from the routes I'd like? I couldn't figure out how.
Define your route for POST /users before the blacklisted routes:
app.post('/users', function(req, res) {
...
});
app.all('*', asyncAuth, requestHandler);
You could maintain a list of regexps that are whitelisted, and match the url against each url in the list, if it matches any then proceed, else require auth
app.all('*', asyncAuth);
function asyncAuth(req, res, next) {
var done = false;
whitelist.forEach(function(regexp) {
if (req.url.match(regexp)) {
done = true;
next();
}
});
if (!done) requireAuth(next);
}
Something along those lines
I'm getting into Node.JS and would like to have flexibility on the routing engine. I want control over the mapping between urls comming and and what methods get fired.
I'd really like to setup placeholders in the route matching to automatically parse parameters too. Something like
{"routes": [
{'route': {'url': '/path/to/resource/[id]'}, "handler": idHandler()},
{'route': {'url': '/path/to/foo/[category]/bar'}, "handler": fooHandler(),
{'route': {'url': '/path/to/resource/'}, "handler": defaultHandler()}}
]};
You can choose a more specific solution (just for routing) like Director, or if you don't want to handle cookies, sessions, redirect functions etc your best option is Express.js or Flatiron (which you can use with Director).
I'll paste the code from the two so you can see how they can help in routing:
Express
app.get('/', function(req, res){
res.send('index page');
});
app.post('/login', function(req, res) {
// login logic
});
Director
//
// define a routing table.
//
var router = new director.http.Router({
'/hello': {
get: helloWorld
}
});
//
// You can also do ad-hoc routing, similar to `journey` or `express`.
// This can be done with a string or a regexp.
//
router.get('/bonjour', helloWorld);
router.get(/hola/, helloWorld);
Resources:
http://expressjs.com/en/guide/routing.html
http://blog.nodejitsu.com/scaling-isomorphic-javascript-code
http://blog.nodejitsu.com/introducing-flatiron
http://howtonode.org/express-mongodb
Yes, Express will be your best option, I think. No need to "re-invent the wheel" so to speak. You can do RegEx's on routes as well, which gives you a ton of flexibility. I suggest reading up on the guide...it has a lot of good info!
http://expressjs.com/en/guide/routing.html
Express.js and Connect have great support for routing, vhosts and a large number of extensions are available out there. For example simple integration of jade template rendering or less stylesheet processing.
Define routes with parameters, regular expressions and different HTTP methods.
app.get('/home', function(req, res) { });
app.post('/save/:contactID', function(req, res) { });
app.all('/params/:required/:andOptional?', function(req, res) { });
See kickstart and kickstart-example for an example of express with enabled jade and less processing.