I am calling a function from an external JS file in my routes file. So, I am trying to export a function from my externalFile.js file. However, when I run the node server, it throws Uncaught ReferenceError: exports is not defined . externalFile.js is in public/javascripts/ and the route files is in routes/.
External file (externalFile.js):
exports.capsolvingComplete = function (stdout){
//Received, display text and hide the spinner, put check in place.
$('#capsolv-complete').css("display", "block")
$('#capsolv-output').text(stdout);
}
Route file:
var express = require('express');
var router = express.Router();
var script = require('../public/javascripts/externalFile.js')
/* GET home page. */
router.get('/', function(req, res) {
res.render('index', { title: 'CapSolv' });
});
router.post('/file-upload', function(req, res){
script.capsolvingComplete("HI");
res.end("success");
})
module.exports = router;
Thank you for your help! Bit of a node noob here.
Looking at your example, mscdex is right. Anything you require in Node is designed to run on the server, and doesn't have access to the browser's DOM.
I would recommend building a REST API that accepts the file upload, stores it, and returns a JSON object containing metadata: i.e. where the file was stored, size, etc., and let your client deal with that.
Related
In our application we store our reports in a user defined folders. User can add their own folders during runtime. Iam showing the history of those files in a web page. on clicking the file name i should show the file from the folder. How can i show the files from a non public directory.Since its given during runtime i havent added them as static dir to the express server.
One idea we tried was to use node-static-server and create a file server with the folder and serve the file. for each file we create this. it works fine but i get an error saying "port already in use". is there any better idea to do this? is this the right approach?
You can do this in NodeJS using a express.static:
const FS = require('fs')
const express = require('express')
const bp = require('body-parser')
const app = express()
function fileTest(req, res, next){
if (/\.|\/|\\/.test(req.params.file))
return res.sendStatus(400)
return next();
}
app.get(
'/static/:file',
fileTest,
function(req, res, next){
req.url = req.url.replace('/static','')
next()
},
express.static(
'./static',
{
fallthrough: false
}
)
)
app.post(
'/static/:file',
fileTest,
bp.text(),
function (req, res) {
FS.writeFile(
'./static/'+req.params.file,
req.body,
function (err) {
if(err)
return res.sendStatus(500)
return res.sendStatus(200)
}
)
}
)
app.listen(
1337
)
This is a simple example showing a server that will:
[POST]
Take a text body and load it into memory( pitfall: large bodies in memory )
Based on the URL, save it as a file in the static folder
[GET]
Search for a file
If found return file
The good news is that you can make the file and then request the file without restarting the server. Bad news is that this is a VERY SLOW server( comparatively to other options ).
As with all examples no good practices were followed, so be sure to adapt it to your needs.
Things to think about as you adopt it:
How do I allow people to save files to other folders?
How do I disallow people from saving files to other folders I don't want them to?
PROPER AUTHORIZATION
I'm facing a strange behaviour with PdfKit. I'm using Nodejs and Express. When I call my route that generate the PDF, the route itself is called twice, and I don't understand why.
Below is the smallest code that recreate this:
var express = require('express'),
app = express();
app.get('/', function (req, res) {
console.log('Route called with referer', req.headers.referer);
var PdfDocument = require('pdfkit'),
doc = new PdfDocument();
doc.pipe(res);
doc.addPage();
doc.end();
});
app.listen(7373, function () {
console.log('started');
});
In the terminal, I have these logs, refreshing only one time the page from the browser:
node tmp/server.js
started
Route called with referer undefined
Route called with referer http://127.0.0.1:7373/
Anyone knows why the route is called one more time automatically?
Ok, after some analysis, I found that it's the browser's PDF viewer that launch a second call. When using wget or curl, I see only one call and one log. So just be aware that code is parsed twice when diplaying the page from the browser.
I have multiple routes, split into different files (my app consists of different "modules", which I maintain in separate folders. For each folder, there is an index.js file in which I manage the routes per module, and I require these in the app.js file).
For every route, I will require to check the auth, and pass the loggedIn status to the header of every page:
//Default variables for the ejs template
var options = {
loggedIn: true
};
res.render("home/home", options);
If the logged in status is true, then the user's name will be displayed. If not, the login / signup labels are displayed.
What is the best way to centralise this, so that I don't need to require the auth script in every of these index.js (route) files?
I need to be able to pass the auth status to the view via the options object (see example).
In your auth, module, use a middleware function. That function can check and store res.locals.loggedIn which will be available for any view that will eventually be rendered. Just make sure the app.use call executes prior to your other routes and it will work properly.
app.use(function auth(req, res, next) {
res.locals.loggedIn = true; // compute proper value here
next();
});
From what I understand you need to do this for every request.One common thing is adding this as middleware so that all the request gets this .
For Example :
var http = require('http');
var connect = require('connect');
var app = connect();
app.use(function(req, res) {
res.end('Hello!');
});
http.createServer(app).listen(3000)
Now for every request , Hello is printed . You could extract this as a module and reuse it across projects. Check here for more details
I have a variable that holds my Sequelize connection, like so:
var sequelize = new Sequelize('database', 'username');
With Kraken.js, how do I pass this into a module? I don't see where I could add this in the index.js configuration file...
Thanks!
(I can't tag this as krakenjs because I don't have enough karma.)
It's a pretty similar setup to what's shown in this guide:
http://sequelizejs.com/articles/express
You would create the model file, (under ./models). You'd need to register this model using the associate function (See previous link).
And to actually use the model, you could replicate the same usage as in the Kraken Shopping cart example https://github.com/lmarkus/Kraken_Example_Shopping_Cart/
eg: (After you've registered your models)
'use strict';
var Product = require('../models/productModel');
module.exports = function (server) {
/**
* Display a list of the products.
*/
server.get('/', function (req, res) {
Product.find(function (err, prods) {
res.render('index', products);
});
});
};
You can add the connection in separate file and export it (http://openmymind.net/2012/2/3/Node-Require-and-Exports/). I store such files in a dir called lib/
Then in the index.js (the starting point of the app) import the file using
require("./lib/..").
And then invoke it in index.js as
app.configure = function configure(nconf, next) {...};
(http://krakenjs.com/#structure_of_a_project)
A good sample app is https://github.com/lmarkus/Kraken_Example_Shopping_Cart
With an express app running on a node server, how would I go about recursively searching for a render file from the full path right back to the beginning of the supplied URL.
For example, if someone was to hit my server with www.somewebsite.com/shop/products/product, the render engine would first check that there is an index.jade file in shop/products/product/. If none is found it would then check shop/products/, and subsequently shop/.
var express = require('express');
var app = express();
app.get('/*', function(req, res){
res.render(req.path + '/index.jade', function(err, html){
// some loopback code which alters the path and recalls the render method
})
});
The problem is that the response object is not passed to the render callback, so I'm unable to recall render on the response. I'm looking to create a loop because the URL paths may be any number of directories deep, so I can't just assume I only need to cascade for a definitive number of times.
Anyone see a way round this?
You should be able to use the response object from the closure. I think (assuming express allows you to call res.render a second time) you could use code like this answer to achieve what you want:
var express = require('express');
var app = express();
app.get('/*', tryRender);
function tryRender(req, res){
res.render(req.path + '/index.jade', function(err, html){
if (err) {
req.path = 'mynewpath';
tryRender(req, res);
}
})
}
Note: You will need to add a base case or this function will recurse infinitely if it doesn't find a view that works :D
In the event that express doesn't allow a subsequent call to res.render, you'll probably need to find out if the file exists on the file system yourself.