Dynamic (i18n) links using expressjs and jade - javascript

I am using expressjs and i18n-node (https://github.com/mashpie/i18n-node). It's working, except for elegant linking. What I have now is this:
app.all(/^\/(\w{2}\/)+(\w*)?/, function(req, res, next) {
var lang = req.params[0];
var type = req.params[1];
req.url = req.url.replace(lang, "");
if(type !== 'javascript' && type !== 'img' && type !== 'css') {
i18n.setLocale(lang.slice(0, 2));
}
next();
});
(I want /foo as well as /en/foo to work). If the language is not specified in the url, the headers are checked, and if not, it defaults to English. By the way, my solution seems less than ideal (I have to make manual checks to see if it is not static content), so if any of you have a better solution I am all ears.
Now, my real problem is making links to internal content. If a user is here: "/en/foo", a "/bar"-link should actually be "/en/bar". I am using jade (for no particular reason other than that it was the default, again open to suggestions..)
I tried adding a helper function to Jade:
app.helpers({
__i: i18n.__
,__n: i18n.__n
,link_to: function(link, text) {
//TODO: how to get request here?
// this should be defined to the absolute base path
var baseUrl = "/";
// only append locale if it is part of the existing url!
var locale = i18n.getLocale();
return '' + text + '';
}
});
.. but it has many problems:
How do I get the base url? So for instance, if the site is located at "http://www.example.com/foo/bar", and I link to "testLink", link_to will generate "http://www.example.com/foo/bar/testLink", instead of "/testLink" or "http://www.example.com/testLink" etc..
How do I determine if the url contains a localization parameter or not? I don't want to append a localization-parameter to the link if it is unnecessary.
The function itself is not great; In Jade it is called like this: := link_to("testUrl", "some link description"). I would rather do something like this:
link_to(href="someUrl")
div some more jade code
(minor) The HTML is written directly in the JS
What is the preferred way to do this? I've been searching and searching, but unable to find a good answer..
This is actually also a general question; i.e how do you link to other internal content, like the link_to in Rails. Simply doing a(href="someAction") is not good enough, as you want it to generate absolute URLs so that the pretty URLs do not break static content links.
Thanks!

I paste code from an own project with i18n, I use a class for dicto and another class to search language by IP:
app.configure(function(){
app.set('views', __dirname + '/views');
app.set('view engine', 'jade');
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(express.cookieParser());
app.use(express.session({
secret: "sessid",
key: 'uwsid',
store: sessionStore
}));
app.use(function (req,res,next) {
if (req.session.uid) {
req.lang = req.session.uid.lang;
next();
} else if (req.cookies.lang) {
req.lang = req.cookies.lang;
next();
} else {
var alang = typeof req.headers['accept-language'] != "undefined" ? req.headers['accept-language'].substr(0,2) : null;
var ipinfows = ipinfo.getInstance();
ipinfows.getInfo(req.connection.remoteAddress, function (err,data) {
if (err) {
req.lang = alang;
res.cookie('lang', alang);
} else if (data && data.error) {
req.lang = alang;
res.cookie('lang', alang);
} else {
console.log("seteando");
req.lang = data.lang.toLowerCase();
for (i in countryLangs) {
if (countryLangs[i].indexOf(data.lang) != -1) {
req.lang = i;
}
}
if (alang != req.lang) {
req.langdifference = alang;
}
res.cookie('lang', req.lang);
}
next();
});
}
});
app.use(app.router);
app.use(express.static(__dirname + '/public'));
});
Before of the routing app.use(app.router); you can define callbacks, in this case I search the lang and define it in a cookie. After I add an dynamicHelper to include the Dicto object into the template:
app.dynamicHelpers({
i18n: function (req,res) {
return new i18n({lang: req.lang});
}
});
With the lang define before that routing. (saving in req.lang), And I can use the i18n halper now from template (with jade):
form.uniForm(action="/account",method="post")
fieldset.inlineLabels
.ctrlHolder
label(for="nickname") #{**i18n.getText('user:nick')**}:
input(type="text",name="nickname",value=everyauth.user.nick)
p.formHint
i18n object now is the same defined on the dynamic helper.

As far as I understand it, express will only call the helper function once (When the template is compiled...)
In the express guide, http://expressjs.com/guide.html, check out dynamicHelpers which should be more useful for your situation (dynamicHelpers provide request and response objects).

Related

How to remove limit parameter from URL in express-paginate?

I am trying to add paging using express-paginate module. But i am getting limit parameter in url like this: http://example.com:3010/feeds?page=2&limit=10.
But i don't want to use limit in url. How i can remove limit from url?
Below is my pug file code.
if paginate.hasPreviousPages || paginate.hasNextPages(pageCount)
.navigation.well-sm#pagination
ul.pager
if paginate.hasPreviousPages
li.previous
a(href=paginate.href(true)).prev
i.fa.fa-arrow-circle-left
| Previous
if pages
each page in pages
a.btn.btn-default(href=page.url)= page.number
if paginate.hasNextPages(pageCount)
li.next
a(href=paginate.href()).next
| Next
i.fa.fa-arrow-circle-right`
I think you can add this by creating a simple middleware function, e.g.
const app = express();
const DEFAULT_PAGE_COUNT = 10;
// Intercept all calls and add a default page count.
app.use(function(req, res, next) {
if (!("limit" in req.query)) {
req.query.limit = DEFAULT_PAGE_COUNT;
}
next();
});
And actually, I believe the module supplies this middleware function, e.g.
// keep this before all routes that will use pagination
// paginate.middleware(limit, maxLimit)
const paginate = require('express-paginate');
app.use(paginate.middleware(10, 50));

can not detect current language (i18next.language) from handlebar helper?

I am using following packages for multi-languages solutions.
var i18next = require('i18next');
var i18nFsBackend = require('i18next-node-fs-backend');
var i18nMiddleware = require('i18next-express-middleware');
Since I am using handlebar as my nodejs template engine, that's I can not use i18next t('key') directly in the HTML.
so I created a handlebar helper like following
```javascript
var i18next = require('i18next');
handlebars.registerHelper('t', function(i18n_key) {
console.log(i18next.language)// always undefined, so i18next.t(i18n_key) always return default translation.
var result = i18next.t(i18n_key);
return new handlebars.SafeString(result);
});
```
However, the problem was the function is unable to detect language changed
My Workaround
app.js
```javascript
var i18nextInitCallback = function(error, t){
handlebars.registerHelper('t', function(i18n_key) {
if(app.locals.language !== i18next.language){
i18next.changeLanguage(app.locals.language);
}
var result = i18next.t(i18n_key);
return new handlebars.SafeString(result);
});
};
```
route
```javascript
router.use(function(req, res, next){
res.locals.lng = req.language;
res.app.locals.language = req.language;
next();
});
```
as you can see that on Route I assign res.app.locals.language = req.language;
and then in the handlebar helper function, I use app.locals.language to get the current language and use i18next.changeLanguage() to change the language.
and it worked.
I would like to know if I am doing it right or not?
or if there is a better solution
Using the handle function of the middleware:
app.use(middleware.handle(i18next, {
// options
}));
res.language gets already set for you and a t function fixed to user language of that request.
see: https://github.com/i18next/i18next-express-middleware/blob/master/src/index.js#L48
check out the handlebars sample: https://github.com/i18next/i18next-express-middleware/tree/master/examples/basic-handlebars

Express alias query strings as params

I am making a project with node, express, and jade. I want to access content through:
/Page/foo/bar
and
/Page?Foo=foo&Bar=bar
I want the top to be an alias for the bottom.
This is the solution I have now:
server.js
// some stuff
app.get('/Page/:Foo/:Bar',function(req,res){
res.render('Page.jade', {Foo: req.params.Foo, Bar: req.params.Bar});
});
app.get('/Page',function(req,res){
res.render('Page.jade', {Foo: req.query.Foo, Bar: req.query.Bar});
});
// more stuff
Page.jade
doctype html
html
head
script var foo = "!{Foo}"; bar = "!{Bar}";
script(src="/Page.js")
// stuff
Page.js
// stuff with foo and bar, such as:
console.log(foo);
console.log(bar);
The thing I don't like about this solution is that it forces me to handle the params and query separately with express (which is almost duplicate code, but not quite close enough to reduce it), pass it to jade, which stores it in a variable for the sole purpose of having a linked javascript file use those variables.
Normally just using query strings I would only have to touch it in Page.js. Is there a way to set up express to effectively interpret the first URL as a query string, like the second URL, so the jade file doesn't have to touch the variables?
Option 1: If you just want to reduce code redundancy, maybe you could save your controllers in an external file, so you will end up with something like this:
controllers/fooBarController.js:
exports.fooBarQueryOrParams = function(req, res) {
res.render('Page.jade', {
Foo: req.params.Foo || req.query.Foo,
Bar: req.params.Bar || req.query.Bar
});
}
You could also add a default value with another || operator if undefined is not valid four you.
server.js:
var fooBarController = require('controllers/fooBarController');
app.get('/Page/:Foo/:Bar', fooBarController.fooBarQueryOrParams);
app.get('/Page', fooBarController.fooBarQueryOrParams);
Option 2: Same thing, but using res.locals, so now there's no need to pass any object to Page.js, all your views will see res.locals properties just by its names, in this case Foo and Bar (not res.locals.Foo and res.locals.Bar).
controllers/fooBarController.js:
exports.fooBarQueryOrParams = function(req, res) {
res.locals.Foo = req.params.Foo || req.query.Foo;
res.locals.Bar = req.params.Bar || req.query.Bar;
res.render('Page.jade');
}
server.js:
var fooBarController = require('controllers/fooBarController');
app.get('/Page/:Foo/:Bar', fooBarController.fooBarQueryOrParams);
app.get('/Page', fooBarController.fooBarQueryOrParams);
Option 3: Always expose everything thought res.locals:
controllers/fooBarController.js:
exports.fooBarQueryOrParams = function(req, res) {
res.render('Page.jade');
}
server.js:
var fooBarController = require('controllers/fooBarController');
app.use(function(req, res, next) {
for (var key in req.params) res.locals[key] = req.params[key];
for (var key in req.query) res.locals[key] = req.query[key];
next();
});
app.get('/Page/:Foo/:Bar', fooBarController.fooBarQueryOrParams);
app.get('/Page', fooBarController.fooBarQueryOrParams);
I would go for the first option as I suppose you don't really need to use Foo and Bar in all your views, so there's no point in using res.locals to expose them to all your views instead of just to the ones that really need them.
You could just set the object properties yourself and continue to the next route etc
app.use('/Page/:Foo/:Bar',function(req, res, next){
for (var key in req.params) {
req.query[key] = req.params[key];
}
next();
});

How use next() properly in routes (node.js)

var s_bookingController = require('s/controllers);
app.get('/dashboard/:page/:param', s_bookingController.index)
app.get('/dashboard/show/:id', s_bookingController.show);
Controllers:
exports.index = function(req, res, next) {
var page = parseInt(req.param("id"));
data = {};
data.page = page;
data.nextPage = page + 1;
data.prevPage = page - 1;
MyModel.find().sort('brand').skip((page-1)*11).limit(11).exec(function(err, result) {
res.render('index', {
data: data,
booking: result,
});
});
};
And
exports.show = function(req, res, next) {
var id = req.param("id");
res.send(id);
};
I'm using this controllers, but there is something wrong with the code of the exports.index, because it's stuck in the code.
If I change the routes to:
app.get('/dashboard/:page', s_bookingController.index)
(Note that I'm take off the second parameter that I was passing)
the show will work, but if I use the second parameter, the show will not run, it will be stuck in the index page.
Why is this? I was wondering if I need use the next();.
Expanding my comment:
You should have the following order of the routes:
app.get('/dashboard/show/:id', s_bookingController.show);
app.get('/dashboard/:page/:param', s_bookingController.index);
Express routing requires that a more specific route should be placed above the more general one.
The /dashboard/show/:id is more specific in this case as /dashboard/:page/:param covers it, so that /dashboard/show is handled by it. When the route is handled next routes are not executed.

Partial update while supporting seo

Using NodeJs I'm trying to do something quite similar to Meteor: I want to send only the parts of a page that actually changed. My dilemma is that I know how to create such a framework to respond to link clicks and send partial updates but such a framework won't cater to direct browsing to a page other than the index (which is what is required for search engines and people without javascript to use your site).
I can also figure out how to make a framework to support entire page reloads, handlebars and a simple node server instance would take care of that. Hoeever, I can't figure out how to create a way that would allow me to write one method to tell the framework the partial updates for a page and let the framework figure out what else needs to be loaded.
A way I can think of would be to create the index page every time (for entire page loads) and apply partial updates to that but that can quickly become expensive if a subpage differs a lot from a very crowded index.
An example method would look something like this:
function images(id) {
if (id == null) {
// load all images from database
template.images = db.result();
template.content = template.loadblock('gallery');
}
else {
// retrieve single image
template.content = template.loadblock('single_image');
template.image = db.result();
}
}
On a partisl updste calling this method for domain.com/images would work just fine because it's clear what had changed.
For an entire page load this function would miss things like a header, footer ,navigation, etc.
In an answer I would look for an example where this has been done or some tips that Can point me in the right direction. I'm sorry for any typoes I wrote this post on an ipad. If you have any questions about my question just ask and I'll update as needed.
Update:
A possible example of a solution might be the following code. It's to give an idea, it probably won't actually run
// As a convention, don't pass around raw values if they aren't static but pass around functions such as
data.images = function () {
// run db query
// return an object with the images
}
// This constraint might be limited to the index() method
var routes = {
// This now allows us to do things like this:
index: function() {
var data;
// Initialise everything needed for the index
data.title = 'Index';
data.nav = { Index: '/', Images: '/images' };
data.content = 'Hello World';
},
categories: function() {
var data;
data.content = render('gallery', function () { /* load and return images as object */ }); // Not sure about this dynamic subtemplating but oh well
}
// This now allows us to do the following:
function request(page, type) {
if (type == 'update') {
if (routes[page] != undefined && typeof routes[page] == 'function') {
respond(routes[page]());
}
}
else {
if (routes[page] != undefined && typeof routes[page] == 'function') {
var data = mergeArrays(routes['index'](), routes[page]());
// index.html which is just a Handlebars template
respond(data);
}
}
}
Here is a pattern I often use (in Express apps):
function respond(req, res, name, resource) {
if(req.accepts('json')) {
// Send JSON to clients who want it
res.send(resource);
} else {
// Render with layout only for non-XHR requests
resource.layout = !req.xhr;
res.render('resources/' + name, resource);
}
}
Example usage:
app.get('/images', function(req, res, next) {
getImages(function(err, images) {
if(err) return next(err);
respond(req, res, 'images', images);
});
});
app.get('/images/:id', function(req, res, next) {
getImage(req.params.id, function(err, image) {
if(err) return next(err);
respond(req, res, 'image', image);
});
});
image.jade:
img(src=uri, alt=title)
images.jade:
#gallery
for image in images
include image
Clients who ask for JSON get that, otherwise they get the full page only if it's a non-XHR request. XHR requests get just the HTML snippet for the requested resource. This works well for quite simple apps, where resources mostly correspond to pages.

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