I'm using SailJS to build a REST API.
I've a lot of nested models, such as:
A building has many Floors, which have many Apartments, which have an Owner.
The Sails populate implementation doesn't work as expected, and I can populate at max a single level nested model.
In order to make things work I would like to rewrite custom controllers like this:
controllers/BuildingController.js
module.exports = {
find: function (req, res) {
// Custom code with population
}
findOne: function (req, res) {
// Custom code with population
}
create: function (req, res) {
// Custom code with nested object creation and connection to parent object
}
...
}
If I call an endpoint through the blueprint my custom controller for that model is called, but if I call it from another point in the code (e.g. Apartment.find()) Sails use its default action, not mine.
Do you have some kind of hint or solution to this problem? Is this possible to implement?
Thanks in advance
i am new in express.js. i used pug for templating. I need to pass a function through res.render() and that will accessible from pug file. Is it possible? If possible then how? please help me.
app.js
passingMethod= (info) => {
console.log(info);
}
app.get('/',(req, res)=>{
res.render('first.pug', {methods: {passingMethod: this.passingMethod}})
});
and first.pug
script.
var onBtnClick= (event) => {
var methods = !{JSON.stringify(methods)}
console.log(methods)
//want to accessing passingMethod function from here
}
.fb-area
.fb
This is good?
button#good(onclick='onBtnClick(event)') Good
button#bad Bad
Depends on the type of function you are passing. Provided your function returns a value, this will be easy. Assign your function as an object to a variable and pass the variable to the res.render() method like this:
//Within your Route or Route-controller
var someVariable = someFunction()
res.render('templateName', {someVariable})
Then Call your variable in pug template
I have a node application and I took the following functionality and put it in separate file in new folder as a new module. In this file I need to handle some action like save delete edit etc. I have two questions:
Should I separate the functionality inside this file to actions and
expose it differently?
In any case how should I call to this functionality with the
parameters which is needed to all the actions like req, res, path?
I'm looking for concrete examples.
This is the code that I use:
module.exports = function () {
const fs = require('fs')
function fileAction (req, res, urlAction) {
switch (urlAction) {
case 'save':
const writeStream = fs.createWriteStream('c://myfile.txt', { flags: 'w' })
req.pipe(writeStream)
req.on('end', function () {
console.log('Finish to update data file')
})
res.end()
break
case 'delete':
case 'update':
default:
}
}
I like this approach more than implementing functions inside and export lexical scope.
Simply with this approach I feel like the concern of "exporting" is separated from the implementation of the functions. In addition to that you can rename the functions you are going to export. Most importantly you might control better what you want and do not want to export.
var delete= function(){
};
var update = function(){
};
var save = function(){
};
module.exports.update = update;
module.exports.delete = delete;
module.exports.save = save;
Then you'll be able to call methods from your main file:
var file = require('./file.js');
file.save();
file.delete();
file.update();
You should do something more object-oriented:
module.exports = {
save: function () {
},
delete: function () {
},
update: function () {
}
}
Then you'll be able to call methods from your main file:
const FileLib = require('./fileLib.js')
FileLib.save()
If you plan to use this as logic inside an Express application, you do not really need to use req and res directly from inside your module except if you are writing an Express middleware or a router.
But what I would recommend you is to use your library from the router:
const FileLib = require('./fileLib.js')
router.put('/file/:id', function (req, res) {
// Do your stuff with your library
FileLib.save(req.param('fileToSave'))
res.send()
})
Your library should not be too coupled to the express architecture unless it's a middleware.
Writing RESTful Express routing might also be a good idea. Use HTTP verbs to specify your action to the API.
In the routes folder of a Node.Js app I have a file entries.js which has the following function:
exports.form = function(req, res){
res.render('post', { title: 'Post' });
};
Is it actually possible to launch something like this from another exports function in the same file, such as:
exports.something = function(req, res){
this.form(req.res);
};
Where this.form refers to exports.form function in the same file.
Thank you!
The value of this by default will point to the object whose member the function is. In this case, both functions are members of the same object, thus using this.form should work as expected.
The exceptions to this rule are when the function in question is used together with bind, call, or apply.
I'm using Express.js (on Node.js) and I know that you can render a view with custom data via the "locals" parameter. (res.render("template", { locals: { foo: "bar" } });)
Is there any way to have "globals"? (ie. data that's accessible to every view)
I saw view options, but that isn't recursive, so it replaces the locals I set if I use any locals with my template.
This is my use case: I want to make it so that CSS/JS files can be added on a per-page basis, and that is part of my main layout. The problem is, if I don't explicitly set those arrays on every render, I get an undefined error, so in my template I always have to do the typeof css !== "undefined" dance. Additionally, I have other select box option lists that I don't want to have to explicitly add to each of my forms.
It's worth noting for those who may have come across this question since the release of Express 3, that the method 'dynamicHelpers' no longer exists.
Instead you can use the app.locals function, which acts as an object you can store values or functions in, and then makes them available to views. For example:-
// In your app.js etc.
app.locals.title = "My App";
app.locals({
version: 3,
somefunction: function() {
return "function result";
}
});
// Then in your templates (shown here using a jade template)
=title
=version
=somefunction()
// Will output
My App
3
function result
If you need access to the request object to pull information from, you can write a simple middle-ware function and use the app.settings variable.
For example, if you are using connect-flash to provide messages to your users, you might do something like this:
app.use(function(req, res, next) {
app.set('error', req.flash('error'));
next();
});
Which would give you access to the error message with =settings.error in your template.
These topics are covered here, albeit slightly briefly: http://expressjs.com/api.html#app.locals
Update: Express 4
app.locals is now a simple JavaScript Object, so every property has to be set one by one.
app.locals.version = 3;
app.locals.somefunction = function() {
return "function result";
}
res.locals provides the exact same functionality, except it should be used for request-specific data rather than application-wide data. A user object or settings is a common use case.
res.locals.user = req.isAuthenticated() ? req.user : null;
res.locals.userSettings = {
backgroundColor: 'fff'
}
There is a way to have "global" variables for views, using dynamic view helpers.
From the Express.js guide:
app.dynamicHelpers(obj)
Registers dynamic view helpers.
Dynamic view helpers are simply
functions which accept req, res, and
are evaluated against the Server
instance before a view is rendered.
The return value of this function
becomes the local variable it is
associated with.
app.dynamicHelpers({ session:
function(req, res){
return req.session; } });
All views would now have session
available so that session data can be
accessed via session.name etc:
You can find a real example on how to use them here: https://github.com/alessioalex/Nodetuts/tree/master/express_samples (node app.js to start the app)
A real-world example of using view options as the author mentioned:
var app = express.createServer();
app.configure(function() {
app.set('views', path.join(__dirname, '..', 'views'));
app.set('view engine', 'jade');
app.set('view options', {
assetVersion: 1
});
And then in my layout.jade (base template for the app in my case):
link(rel='stylesheet', href='/static/css/' + assetVersion + '/style.css')
script(src='/static/js/' + assetVersion + '/script.js')
With this little trick, I only have to update the assetVersion variable one place to make sure that my assets aren’t cached in Varnish or other places.
I wound up looking into the source code, and I've actually found that this is now possible in never versions of Express. (so far, only available through GitHub)
The simplest way to accomplish this is to create a variable that represents the default set of locals for your views. Then create a function that accepts an object, merges it with the locals, and returns the merged object.
I also pass ALL my locals inside a container object i.e. {locals:{g:{prop:val}}} so in my views I can refernce g.prop which will just return null when it isn't set, instead of throwing an undefined error.
function default_page_vars(custom_vars){
var vars = {
footer: true,
host: req.headers.host.split(':')[0],
config: this.config
};
if(custom_vars){
for(var k in custom_vars){
vars[k] = custom_vars[k];
}
}
return {
g:vars
};
}
//within your handler
response.render(view, {
locals: default_page_vars(other_locals)
});
This is a buried response, but I finally got it to work.
1) This is an example around the module connect-flash
2) Add a piece of middleware in server.js/app.js to add req to locals. This allows the template to call request.flash() whenever it needs. Without this, flash() gets consumed on each request/redirect defeating the purpose.
var app = module.exports = express()
, flash=require('connect-flash');
app.configure(function(){
...
app.use(express.session({ secret: "shhh" }));
// Start Router
app.use(flash());
app.use(function(req, res, next) {
res.locals.request = req;
next();
});
app.use(app.router);
});
3) Setup your route as normal (this is coffeescript, but nothing special)
app.get '/home', (req, res) ->
req.flash "info", "this"
res.render "#{__dirname}/views/index"
4) Call request.flash() when you want the messages. They are consumed on each call, so don't console.log them or they'll be gone :-)
!!!
html
head
title= config.appTitle
include partials/_styles
body
include partials/_scripts
#header
a(href="/logout") Logout CURRENTUSER
h2= config.appTitle
#messages
- var flash = request.flash()
each flashType in ['info','warn','error']
if flash[flashType]
p.flash(class=flashType)
= flash[flashType]
block content
h1 content here
Express 4
You can access local variables in templates rendered within the application.
So, if you want to use any locals in your template => assuming you have a template engine npm installed to your node/express application.
First, you need to set the express locals objects with your custom variables in your app.js file, you can use an object if multiple values are needed (our case in this post)
/**
* Set locals object
*/
app.locals.layoutData = {
site: {
title: 'MyWebSiteTitle',
},
metaTag: {
charset: 'UTF-8',
description: 'MyDescription',
keywords: 'keyword-1,keyword-2,...',
author: 'MyName',
viewport: 'width=device-width, initial-scale=1.0'
}
};
Then, to access the values in the template file layout.pug (in the case of PUG template engine for instance)
doctype html
html
head
//title
title #{locals.layoutData.site.title}
//Describe metadata
meta(charset=layoutData.metaTag.charset)
meta(name='description', content=locals.layoutData.metaTag.description)
meta(name='keywords', content=locals.layoutData.metaTag.keywords)
meta(name='author', content=locals.layoutData.metaTag.author)
meta(name='viewport', content=locals.layoutData.metaTag.viewport)
body
block content
br
hr
footer
p All rights reserved © 2018 | #{locals.layoutData.site.title}
Tested with
"dependencies": {
"express": "^4.16.3",
"pug": "^2.0.3"
}