I'm trying to update my mongodb database in javascript by accessing some documents from the database, changing a specific document and then performing a patch request via axios.
When I get to the patch request I'm able to update the database however the promise is stuck on pending and thus, the then() part of the code is not run.
This is the main structure of the code:
In the first part the documents are requested from the database via axios.get:
function updateDocument(someinputdata){
g = axios.all([axios.get('/getData1),axios.get('/getData2)])
.then(response => {
Data1 = response[0].data;
Data2 = response[1].data;
adjustData(Data1,Data2);
});
}
In the second part a specific document is changed and a patch request is called:
function adjustData(Data1,Data2){
...getting specific document and change value from specific field...
var newRec = {
title: "dummyTitle",
rate: newRateValue
};
promise = axios({
url: '/patch/The Real Title',
method: 'PATCH',
data: newRec,
headers: { "Content-Type": "application/json" }
})
.then(() => {
console.log('I want this text to display but it doesn't')
});
}
If I console.log(promise):
Promise {<pending>}
__proto__: Promise
[[PromiseState]]: "pending"
[[PromiseResult]]: undefined
On the server side I have this:
router.patch('/patch/:title', (req,res) => {
const updatedPost = Model.updateOne(
{ "title": req.params.title},
{ $set: { "rate" : req.body.rate}},
(err, result) => {
if(err) {
console.log(err);
throw err;
}
})
.then(
console.log('This text is displayed');
)
})
I want to use the first then() part to update some HTML
Why is the patch request stuck on pending (so not fulfilled or rejected)?
I've figured out what my problem was.
I needed to add
res.json({msg: "Your data has been saved"});
to the code on the server side.
Related
Say I have a list of models:
const documents = [{}, {}, {}];
And I want to insert these into the DB, or update them all, but only if a condition is met:
Model.update({isSubscribed: {$ne: false}}, documents, {upsert:true},(err, result) => {
});
The above signature is surely wrong - what I want to do is insert/update the documents, where the condition is met.
There is this Bulk API:
https://docs.mongodb.com/manual/reference/method/Bulk.find.upsert/
but I can't tell if it will work when inserting multiple documents.
Imagine this scenario: We have a list of employees and a form of some sorts to give them all a penalty, at once, not one by one :)
On the backend side, you would have your eg addBulk function. Something like this:
Penalty controller
module.exports = {
addBulk: (req, res) => {
const body = req.body;
for (const item of body) {
Penalty.create(item).exec((err, response) => {
if (err) {
res.serverError(err);
return;
}
});
res.ok('Penalties added successfully');
}
}
Then you'll probably have an API on your frontend that directs to that route and specific function (endpoint):
penaltyApi
import axios from 'axios';
import {baseApiUrl} from '../config';
const penaltyApi = baseApiUrl + 'penalty'
class PenaltyApi {
static addBulk(penalties) {
return axios({
method: 'post',
url: penaltyApi + '/addBulk',
data: penalties
})
}
}
export default PenaltyApi;
...and now let's make a form and some helper functions. I'll be using React for demonstration, but it's all JS by the end of the day, right :)
// Lets first add penalties to our local state:
addPenalty = (event) => {
event.preventDefault();
let penalty = {
amount: this.state.penaltyForm.amount,
unit: this.state.penaltyForm.unit,
date: new Date(),
description: this.state.penaltyForm.description,
employee: this.state.penaltyForm.employee.value
};
this.setState(prevState => ({
penalties: [...prevState.penalties, penalty]
}));
}
Here we are mapping over our formData and returning the value and passing it to our saveBulkEmployees() function
save = () => {
let penaltiesData = Object.assign([], this.state.penalties);
penaltiesData.map(penal => {
penal.employeeId = penal.employee.id;
delete penal.employee;
return penaltiesData;
});
this.saveBulkEmployees(penaltiesData);
}
...and finally, let's save all of them at once to our database using the Bulk API
saveBulkEmployees = (data) => {
PenaltyApi.addBulk(data).then(response => {
this.success();
console.log(response.config.data)
this.resetFormAndPenaltiesList()
}).catch(error => {
console.log('error while adding multiple penalties', error);
throw(error);
})
}
So, the short answer is YES, you can absolutely do that. The longer answer is above :) I hope this was helpful to you. If any questions, please let me know, I'll try to answer them as soon as I can.
I'm having trouble communicating between the frontend and backend for a selected GET request.
I am using a React frontend with an express/mongoose setup out in the backend.
In the frontend, I do a GET call using axios for:
axios.get('/api/orders/', {
params : {
name: this.props.user.name // user name can be Bob
}
})
And in the backend I'm having a hard time understanding the correct method I would need to do to query the database (example below doesn't work). I found stuff with .select but even then I still can't get it to work:
router.get('/orders', function(req, res) {
Order.find({}).select(req.params).then(function (order) {
res.send(req.params);
})
});
I also tried doing this to see if I can even get the params to send properly and to no demise:
router.get('/orders/:name', function(req, res) {
res.send('client sent :',req.query.name);
});
The orders document model holds objects that house an ordered array and a name (type: String) attached to the object. The Mongoose scheme for the order:
const orderScheme = new Schema({
name : { type : String },
orders : { type : Array}
});
In my MongoDB, I can see all the "Master Orders" send back. Each master order has the name of who submitted it, plus all the orders within (there can be a ton of orders).
What I'm trying to exactly do is pull up all orders that have a certain name. So if I search "TestAccount", I'll get all of bob's orders. I've included an image below:
Any pointers?
Client-side:
axios.get('/api/orders/' + this.props.user.name)
.then(function (response) {
// handle success
console.log(response);
})
.catch(function (error) {
// handle error
console.log(error);
})
You need to handle the Promise when resolved/rejected.
Server-side:
router.get('/orders/:name', function(req, res) {
return Order.find({name: req.params.name}).then(function(orders) {
// return orders when resolved
res.send(orders);
})
.catch(function (error) {
// handle error
console.log(error);
})
});
You did not specify a named route parameter in your route path.
You also aren't accessing the name property by using req.params only.
You should use Model.find() conditions parameter to specify which document[s] you're trying to find. Query.prototype.select() is for filtering document fields.
I have a route that adds an image (a meme) like this:
// add new image by URL
app.post('/api/addMeme', function (req, res) {
var meme = new Meme({
title: req.body.title.trim().toLowerCase(),
image: req.body.image,
meta: {
votes: 0,
favs: 0
},
related: []
});
// Save meme to database
meme.save(function (err) {
if (err) throw err;
Meme.find({}, function (err, meme) {
if (err) throw err;
io.emit('new meme', meme);
});
res.send('Succesfully inserted meme.');
});
});
It takes the only two attribute title and image given by client side ajax and add it to my Mongodb database named Meme. Emit the updated database using socket.io. Both title and image are String type. image is suppose to be an URL to an image.
Now, I'm not ashamed to admit it, but my friend trolled my site and sent image = "www.pornhub.com" to this route and it crashed my database/site. Whenever I go and try to retrieve the image by its _id, I get the error:
CastError: Cast to ObjectId failed for value "www.pornhub.com" at path "_id" for model "meme"
EDIT: it looks like the error is actually coming from the route
app.post('/api/vote', function(req, res){
Meme.findOneAndUpdate({_id: req.body.id}, {$inc : {'meta.votes' : 1}}, {new: true}, function (err, meme) {
if (err) throw err;
if (!meme) return res.send('No meme found with that ID.');
io.emit('new vote', meme);
res.send('Succesfully voted meme.');
});
});
where a POST request is updating the database, and there's a cast error where the _id is given as a string?
The client side script that's doing this is
$("#vote").click(function(){
$.ajax({
type: "POST",
url: '/api/vote',
data: {
id: App.meme._id
},
success: function (data, status) {
console.log(data);
}
});
return false;
});
where App is a Express-state exposed data for which meme, the database, lives under.
But this error ONLY occurs on the object with image = "www.pornhub.com". My guess is that somewhere in the HTML, a cross-site href is visiting www.pornhub.com and somehow App is getting distorted? It doesn't fully make sense why id: App.meme._id would give www.pornhub.com as its value.
I am a beginner with Node.js and Mongoose. I spent an entire day trying to resolve an issue by scouring through SO, but I just could not find the right solution. Basically, I am using the retrieved values from one collection to query another. In order to do this, I am iterating through a loop of the previously retrieved results.
With the iteration, I am able to populate the results that I need. Unfortunately, the area where I am having an issue is that the response is being sent back before the required information is gathered in the array. I understand that this can be handled by callbacks/promises. I tried numerous ways, but I just haven't been successful with my attempts. I am now trying to make use of the Q library to facilitate the callbacks. I'd really appreciate some insight. Here's a snippet of the portion where I'm currently stuck:
var length = Object.keys(purchasesArray).length;
var jsonArray = [];
var getProductDetails = function () {
var deferred = Q.defer();
for (var i = 0; i < length; i++) {
var property = Object.keys(purchasesArray)[i];
if (purchasesArray.hasOwnProperty(property)) {
var productID = property;
var productQuery = Product.find({asin:
productQuery.exec(function (err, productList) {
jsonArray.push({"productName": productList[0].productName,
"quantity": purchasesArray[productID]});
});
}
}
return deferred.promise;
};
getProductDetails().then(function sendResponse() {
console.log(jsonArray);
response = {
"message": "The action was successful",
"products": jsonArray
};
res.send(response);
return;
}).fail(function (err) {
console.log(err);
})
});
I am particularly able to send one of the two objects in the jsonArray array as the response is being sent after the first element.
Update
Thanks to Roamer-1888 's answer, I have been able to construct a valid JSON response without having to worry about the error of setting headers after sending a response.
Basically, in the getProductDetails() function, I am trying to retrieve product names from the Mongoose query while mapping the quantity for each of the items in purchasesArray. From the function, eventually, I would like to form the following response:
response = {
"message": "The action was successful",
"products": jsonArray
};
where, jsonArray would be in the following form from getProductDetails :
jsonArray.push({
"productName": products[index].productName,
"quantity": purchasesArray[productID]
});
On the assumption that purchasesArray is the result of an earlier query, it would appear that you are trying to :
query your database once per purchasesArray item,
form an array of objects, each containing data derived from the query AND the original purchasesArray item.
If so, and with few other guesses, then the following pattern should do the job :
var getProductDetails = function() {
// map purchasesArray to an array of promises
var promises = purchasesArray.map(function(item) {
return Product.findOne({
asin: item.productID // some property of the desired item
}).exec()
.then(function product {
// Here you can freely compose an object comprising data from :
// * the synchronously derived `item` (an element of 'purchasesArray`)
// * the asynchronously derived `product` (from database).
// `item` is still available thanks to "closure".
// For example :
return {
'productName': product.name,
'quantity': item.quantity,
'unitPrice': product.unitPrice
};
})
// Here, by catching, no individual error will cause the whole response to fail.
.then(null, (err) => null);
});
return Promise.all(promises); // return a promise that settles when all `promises` are fulfilled or any one of them fails.
};
getProductDetails().then(results => {
console.log(results); // `results` is an array of the objects composed in getProductDetails(), with properties 'productName', 'quantity' etc.
res.json({
'message': "The action was successful",
'products': results
});
}).catch(err => {
console.log(err);
res.sendStatus(500); // or similar
});
Your final code will differ in detail, particularly in the composition of the composed object. Don't rely on my guesses.
I've been having this weird issue with an application I'm building. Essentially a function is invoked I want to read in a user's current game statistics -Wins, losses, draws etc - I do this using a service which creates an observable and consumes data from my rest api. On first call of this method the data read in is the most current up to date version but after this point I update the document for the user in the database and then when I execute the function again it reads in the original document before the update. However when I check the database the document has in face been updated.
Here is my provider function for consuming the data.
getUser(id) {
if (this.data) {
return Promise.resolve(this.data);
}
return new Promise(resolve => {
this.http.get('https://pitchlife-hearts.herokuapp.com/api/users/' + id)
.map(res => res.json())
.subscribe(data => {
this.data = data;
resolve(this.data);
});
});
}
Here is the call I make in my function.
play(challenger, opponent) {
this.userService.getUser(_id).then((data) => {
this.challenger_account = {
_id: data._id,
points: data.maroon_points,
wins: data.wins,
draws: data.draws,
losses: data.losses
};
Here is my update call.
this.userService.updateUser(this.challenger_account);
Here is my api endpoint call as well although this does work every time I update the data.
app.post('/api/users/update', function (req, res) {
// Update a user
var options = {};
User.update({_id : req.body._id }, {
maroon_points: req.body.points,
wins: req.body.wins,
draws: req.body.draws,
losses: req.body.losses
}, options,
function (err, user) {
if (err)
res.send(err);
res.json(user);
});
});
Any help with this would be hugely appreciated as this is driving me crazy.
When are you updating the this.data property that the getUser(id) { ... } method uses?
Because the first time the getUser(id) {...} method is executed, this.data is null and because of that the http request is made. But after that, the value of this.data is always returned, but if you don't update it manually, it'll be always the first value it was set to.