I have using node.js to develop a application that grabs an user's avatar file saved I the file system.
var fs = require('fs');
fs.exists(__dirname + "/../public/uploaded/users/" + user.username + "/avatar.png", function(exists){
if(exists){
//...
} else {
//...
}
}
But this checks only if avatar.png exists. Some avatar file such as avatar.gif or avatar.jpg could also be grabbed.
I know I can put three level of if statements inside if(exists) but I want to know a better way.
Thanks,
Dennis
I'm not sure if there is an easy native method but this library seems like it would do what you are looking for: https://github.com/isaacs/node-glob
Related
so I'm making a site with node js, and I need to use localstorage, so I'm using the node-localstorage library. So basically, in one file I add data to it, and in another file I want to retrieve it. I'm not 100% sure about how to retrieve it. I know I need to use localStorage.getItem to retrieve it, but do I need to include localStorage = new LocalStorage('./scratch');? So I was wondering what the localStorage = new LocalStorage('./scratch'); did. So here is my code for adding data:
const ls = require('node-localstorage');
const express = require("express");
const router = express.Router();
router.route("/").post((req, res, next) => {
var localStorage = new ls.LocalStorage('./scratch');
if(req.body.name != undefined){
localStorage.setItem("user", req.body.name);
res.redirect('/')
}
else{
console.log("undefind")
}
});
module.exports = router;
If my question is confusing, I just want to know what var localStorage = new ls.LocalStorage('./scratch'); does.
A drop-in substitute for the browser native localStorage API that runs on node.js.
It creates an instance of the "localStorage" class, which this library provides. The constructor expects the location of the file, the scripts stores the key, value elements in.
Opinion: This looks pointless to me - I guess it fits your use case.
I want to implement a functionality in nodejs. I have two different controllers in my node application. I has the responsibility to store the file (abc.xlsx) into local folder(mylocation) using fs module and i have done it successfully. And in my another controller i have to read the locally stored file(abc.xlsx).
Is it possible. Everytime i want to write a file from one controller and read the same from another controller. I have tried something as like the following..
exports.controller1 = function(req,res){
if(req.files.file){
fs.readFile(req.files.file.path,function(err,data){
var fileName = req.files.file.name;
getfileName(fileName);
some logic goes here......
});
}
}
function getFileName(fileName){
console.log(fileName);
}
exports.controller2 = function(req,res){
getFileName(fileName);
var filePath = fileName;
my logic goes here...
}
Need some help to get the fileName or the filePath to read a file
Thanks in advance.
I'm working on an app that creates a PDF document on the server, then displays a Download Here button. When I click the button, the process appears to work. When I inspect the Network>Preview and Network>Headers tabs in the Chrome console I can see that the file has definitely been returned.
The problem is, it does not display and it does not offer the option to save. Am I missing a client side step here? My preferred outcome is either to give the user the option to save the file or to automatically begin the download to their default path.
Here is relevant the server code:
exports.show = function(req, res) {
var file = req.params.id;
var filePath = __dirname + '../../../lib/completedforms/';
var thisPath = path.resolve(filePath + file);
res.attachment(thisPath);
res.setHeader('Content-Type', 'application/pdf');
res.setHeader("Content-Disposition", "attachment");
res.download(thisPath);
};
Thanks in advance for any guidance here.
There's no need for both res.attachment() AND res.download(). Just use the latter.
Also, res.download() already sets the Content-Disposition header, so you can remove that too.
You can also simplify your path generation:
var thisPath = path.resolve(__dirname, '../../../lib/completedforms/', file);
Although you should probably sanitize file and/or check that thisPath is not some location where it shouldn't be. This will prevent someone from supplying a potentially malicious req.params.id value like ../../../../../../../etc/passwd.
I guess it is just a simple question but I can't solve it on my own.
(I'm using Express + NodeJS)
What I would like to have is a directory listing with the files contained in it. The files shall be linked so that a user could download them by just clicking the link (like the standard directory listing you get if you have e.g. a apache server without any index file).
To list the directory content I use
var fs = require('fs');
fs.readdir('./anydir', function(err, files){
files.forEach(function(file){
res.send(file);
});
});
(Notice: I did not include any error handling in this example as you can see)
Now I tried to just link the file by modifying the
res.send(file)
to
res.send('<a href=\"' + file + '\">' + file + '<br>');
but this just prints out the error message:
Cannot GET /anydir/File
... because I did not handle every file request in app.js.
How can I achieve my goal mentioned above?
Just use express.directory and express.static as middleware, possibly with a user-defined middleware to set Content-Disposition headers.
This worked for me:
var fs = require('fs');
fs.readdir('/var/', function(err, files){
files.forEach(function(file){
res.write('<a href=\"' + file + '\">' + file + '<br>');
});
});
You put the content with write() not send().
Try this and let me know. I can see the list of files displayed correctly.
Hope this helps you.
I'm new in the world of Node.js
According to this topic: What is Node.js' Connect, Express and “middleware”?
I learned that Connect was part of Express
I dug a little in the code, and I found two very interesting files :
./myProject/node_modules/express/lib/utils.js
and better :
./myProject/node_modules/express/node_modules/connect/lib/utils.js
These two files are full of useful functions and I was wondering how to invoke them correctly.
As far, in the ./myProject/app.js, that's what I do:
var express = require('express')
, resource = require('express-resource')
, mongoose = require('mongoose')
, expresstUtils =
require('./node_modules/express/lib/utils.js');
, connectUtils =
require('./node_modules/express/node_modules/connect/lib/utils.js');
But I found it a little clumsy, and what about my others files?
e.g., here is one of my routes:
myResources = app.resource(
'myresources',
require('./routes/myresources.js'));
and here is the content of myresources.js:
exports.index = function(req, res)
{
res.render('./myresources.jade', { title: 'My Resources' });
};
exports.show = function(req, res)
{
fonction resourceIsWellFormatted(param)
{
// Here is some code to determine whether the resource requested
// match with the required format or not
// return true if the format is ok
// return false if not
}
if (resourceIsWellFormatted(req.params['myresources']))
{
// render the resource
}
else
{
res.send(400); // HEY! what about the nice Connect.badRequest in its utils.js?
}
};
As you can see in the comment after the res.send(400), I ask myself if it is possible to use the badRequest function which is in the utils.js file of the Connect module.
What about the nice md5 function in the same file?
Do I have to place this hugly call at the start of my myresources.js to use them?:
var connectUtils =
require('../node_modules/express/node_modules/connect/lib/utils.js');
or, is there a more elegant solution (even for the app.js)?
Thank you in advance for your help!
the only more elegant way i came up with is (assuming express is inside your root "node_modules" folder):
require("express/node_modules/connect/lib/utils");
the node installation is on windows, node version 0.8.2
and a bit of extra information:
this way you don't need to know where you are in the path and be forced to use relative paths (./ or ../), this can be done on any file nesting level.
i put all my custom modules inside the root "node_modules" folder (i named my folder "custom_modules") and call them this way at any level of nesting:
require("custom_modules/mymodule/something")
If you want to access connect directly, I suggest you install connect as a dependency of your project, along with express. Then you can var utils = require('connect').utils.