Render multiple variables with express - node.js

I'm pretty new to express! I didn't find the solution here as my console.log perfectly prints out the "user". However, when I display final page the user-data won't show up. It's just empty. Only the concert-data becomes visible on the page. Now I wonder if what I did is even "allowed".
Any Ideas on why the user data does not show up on the rendered page?
app.get("/concerts/:id", function(req, res){
Concert.findById(req.params.id, function(err, concert){
if(err){
console.log(err);
} else {
User.find({username: "tyrel"}, function(err, user){
if(err){
console.log(err);
} else {
console.log(user);
res.render("concert", {user: user, concert: concert});
}
})
}
});
});

The find() function calls the users as an array, so I had to define an index in my ejs file. <%=user[0].avatar%>

Related

How to access parent modules when doing layered routing in mongoDB

As a personal project, I'm trying to build a social media site for teddy bear collectors. I would like users to be able to make a "collection" page which they can populate with individual profile pages for each of their bears. Finally, I would like other users to be able to comment on both the collection page and the individual profile pages.
However, I'm running into an error on the "/new" route for comments on the individual profile pages. I can't get it to find the id for the parent collection.
Below is the code I'm working with. I start by finding the id for the collection, then I get try to get the id for the bear (individual profile page). However, the process keeps getting caught at the first step.
var express = require("express");
var router = express.Router({mergeParams: true});
var Bear = require("../models/bear");
var Comment = require("../models/comment");
var Collection = require("../models/collection");
var middleware = require("../middleware");
//comments new
router.get("/new", middleware.isLoggedIn, function(req, res) {
Collection.findById(req.params.id, function(err, foundCollection) {
if(err || !foundCollection){
req.flash("error", "Collection not found");
return res.redirect("back");
}
Bear.findById(req.params.bear_id, function(err, foundBear) {
if(err){
res.redirect("back");
} else {
res.render("bcomments/new", {collection_id: req.params.id, bear: foundBear, collection: foundCollection});
}
});
});
});
//bcomments create
router.post("/", middleware.isLoggedIn, function(req, res){
Collection.findById(req.params.id, function(err, foundCollection) {
if(err || !foundCollection){
req.flash("error", "Collection not found");
return res.redirect("back");
}
//look up bear using id
Bear.findById(req.params.id, function(err, foundBear){
if(err){
console.log(err);
res.redirect("/bears" + bear._id);
} else {
//create new comment
Comment.create(req.body.comment, function(err, comment){
if(err){
req.flash("error", "Something went wrong");
console.log(err);
} else {
//add username and id to comment
comment.author.id = req.user._id;
comment.author.username = req.user.username;
//save comment
comment.save();
//connect new comment to bear
bear.comments.push(comment);
bear.save();
//redirect bear show page
req.flash("success", "Successfully added comment");
res.redirect("/collections/" + foundCollection._id + "/bears/" + foundBear._id);
}
});
}
});
});
});
So, instead of rendering the new comment form, it hits a "null" error and redirects back at the first if statement.
If anyone can help me figure this out, I'd be exceedingly grateful.
Thank you.
I think the problem is that you are defining the path "/new" (which has no parameters) and trying to access req.params.id. If you expect to have the parameter id you should define it in the path like this: router.get("/new/:id", .... Check the Express oficial documentation for more details.
EDIT:
You may have mixed req.params with req.query and req.body. If you are passing parameters in the request, you must access them through req.query (for example: req.query.id or req.query.bear_id) in the case of GET and DELETE or through req.body in POST and PUT.

GET request with different mongo find results on same page

I would like my website to have a search bar in the top section that returns a single document (ink) from a mongo database. On the same page, I would like to be able to access all documents from the same database.
I'm having trouble trying to figure out how to do this on one page, since I can only send one result to URL.
Is there some way to send all documents to the page, then do a search with AJAX on the client side? I'm new to coding, and wondering if I'm going about this wrong.
I appreciate any help. Here is part of my code that sends the results I want, but to different pages.
app.get("/", function(req, res){
// FIND ONE INK FROM DB
var noMatch = null;
if(req.query.search) {
Ink.find({ink: req.query.search}, function(err, foundInk){
if(err){
console.log(err);
} else {
if(foundInk.length < 1) {
noMatch = "No match, please try again.";
}
res.render('new-index', {ink: foundInk, locationArray: locationArray, noMatch: noMatch })
}
});
} else {
// FIND ALL INKS FROM DB
Ink.find({}, function(err, allInks){
if(err){
console.log(err);
} else {
res.render("index", {ink: allInks, locationArray: locationArray, noMatch: noMatch });
}
});
}
});
You can use separated endpoints for each request. For the full access request, you can render the page, calling res.render, and for the search request, you can return a json calling res.json. Something like this:
app.get("/", function(req, res){
// FIND ALL INKS FROM DB
Ink.find({}, function(err, allInks){
if(err){
console.log(err);
} else {
res.render("index", {ink: allInks, locationArray: locationArray, noMatch: noMatch })
}
});
})
app.get("/search", function(req, res) {
// FIND ONE INK FROM DB
var noMatch = null;
Ink.findOne({ink: req.query.search}, function(err, foundInk){
if(err){
console.log(err);
} else
if(!foundInk) {
noMatch = "No match, please try again.";
}
res.json({ink: foundInk, locationArray: locationArray, noMatch: noMatch })
}
});
});
Note the call to Ink.findOne in the /search handler, which will return only one document.
This way you can make and AJAX request to /search, and parse the json returned from the server.
I've created a sample repository with the exact same issue here
Ideally you make an endpoint like this.
( id parameter is optional here...thats why the '?' )
www.example.com/api/inks/:id?
// return all the inks
www.example.com/api/inks
// return a specific ink with id=2
www.example.com/api/inks/2
So now you can render all the links via /inks and search a particular ink by using the endpoint /ink/:id?
Hope this helps !

Return 404 code in proper way instead empty array

I have an quite simple application the idea is that someone has unique code which value are stored in one mongo collection in other we are keeping some data which we need to return if the key was found in first collection.
As probably you have noticed I'm using NodeJS with MongoDB and Mongoose, Express.
I have a problem with method bellow:
exports.getCompanyByKey = function(req, res) {
console.log(req.params.keyvalue);
var query = Company.where({keyValue : req.params.keyvalue});
query.findOne(function(err, company){
if(err){
res.send(err);
}else{
SampleData.findOne({}, function(err, sample_data){
if(err)
res.send(err);
res.json(sample_data);
});
}
});
};
The problem is that it will always return the data beause it's not throwing an error but empty array - so is there any other good and proper way as it should be don to throw 404 error without statement such as if(length<0) res.status(404).send('Error message).
I simply want to minimalize amount of if statements.
Maybe there is some other way to write implementation od error handling for mongoose which in general instead returning empty array will give us error code with message?
It's not exactly clear what you're asking, but if you want to make an error condition out of something that is not normally an error, then an if statement (or some other test like that) is required to test for that specific condition.
You could make your own function for querying that turns an empty response into an error and you could "hide" the if condition in that function if you want, but it's still an if condition that tests for your specific condition.
So, to return a 404 if the array is empty, you would just add an if statement (as you already appear to know):
exports.getCompanyByKey = function(req, res) {
console.log(req.params.keyvalue);
var query = Company.where({keyValue : req.params.keyvalue});
query.findOne(function(err, company){
if(err){
res.status(500).send(err);
} else {
SampleData.findOne({}, function(err, sample_data){
if(err) {
res.status(500).send(err);
} else {
if (sample_data.length) {
res.json(sample_data);
} else {
res.status(404).send("no data");
}
}
});
}
});
};
FYI, you also need to make sure you are properly setting a status code when there's an error and that you are never sending multiple responses to the same request (even when there's an error). I've also fixed several cases of those issues in your code.
This could likely be written cleaner and responses consolidated by using the promise interface to your database and send an error in one .catch().
For example, you could simplify your code by creating a utility function for .findOne() that detects and sends an error response automatically:
function findOne(res, db, q, cb) {
db.findOne(q, function(err, data) {
if (err) {
res.status(500).send(err);
cb(err);
} else if (!q.length) {
res.status(404).send("no data");
cb(new Error("no data"));
} else {
cb(null, data);
}
});
}
Then, your function could be simplified to this:
exports.getCompanyByKey = function(req, res) {
var query = Company.where({keyValue : req.params.keyvalue});
query.findOne(function(err, company){
if(err){
res.status(500).send(err);
} else {
findOne(res, SampleData, {}, function(err, sample_data) {
// any error response has already been sent
if (!err) {
res.json(sample_data);
}
});
}
});
};
Again, this would be better to use your Db's promise interface.

Pull mongo data to ejs template

I have the following basic document in mongo:
connecting to: test
> db.car.find();
{ "_id" : ObjectId("5657c6acf4175001ccfd0ea8"), "make" : "VW" }
I am using express, mongodb native client (not mongoose) and ejs.
collection.find().toArray(function (err, result) {
if (err) {
console.log(err);
} else if (result.length) {
console.log('Found:', result);
mk = result;
console.log('mk = ', mk);
} else {
console.log('No document(s) found with defined "find" criteria!');
}
//Close connection
db.close();
});
}
});
Here is the render code:
// index page
app.get('/', function(req, res) {
res.render('pages/index', { make: result });
});
And i want to pass the data make: VW into my index.ejs file:
<h2>Cars:</h2>
<h3>My favorite make is <%= make %>
This should be real simple and straightforward but i just don't understand how to pass the "mk" variable (which i can console.log to the screen) to be rendered by the ejs view?
You should use the find method inside the route (or with a callback) to get the result and render it:
app.get('/', function(req, res) {
collection.find().toArray(function(err, result) {
if(err) {
console.log(err);
res.status('400').send({error: err});
} else if(result.length) {
console.log('Found:', result);
mk = result;
console.log('mk = ', mk);
res.render('pages/index', {make: mk});
} else {
console.log('No document(s) found with defined "find" criteria!');
res.status('400').send({error: 'No document(s) found'});
}
//Close connection
db.close();
});
});
Very simple, your are outputting an array of JSON objects
Here is one way to visualise it:
[{a:b},{a:b},{a:b},{a:b}];
If you want the first result it would be array[0].a
so you simply need to call it this way:
<%= make[0].(your database key here) =>
//example
<%= make[0].name =>
A more sensible way to get this done would be to iterate through the array and output only the result you want on the server side. If you send all your data to your client you might have security issues depending on what you send.
It should be simple, but you are defining mk just like this: mk = result So because you want to pass a variable to an ejs file you need
"var mk = result"
Have a good day, Ben.

what is the benefit to using mongoose .exec?

User.find().exec(function (err, users) {
if (err){
callback(err);
} else {
callback(users);
}
});
User.find(function (err, users) {
if (err) {
callback (err);
} else {
callback(users);
}
});
What is the benefit of using the top code? both seem to work equally well
They are identical and there's no benefit in your example
When you do not pass a callback to find function it won't execute but instead returns a query then you need to use exec()
var query = User.find();
now you can add some more criteria
query.where({age: 15});
and some more
query.select({name:1}); // or {firstname:1, lastname:1} etc.
now you've built up your query so to get the results you need to execute it.
query.exec(function(err, users){
});
But you can also do this like
User.find({age:15}, {name:1}, function(err, users){
});
Above is identical to
User.find({age:15}, {name:1}).exec(function(err, users){
});
since there's no callback in find function it will return query which means no results, exec will give you the results

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