Cursor.forEach in Express hanging when document not found - node.js

I'm using the MongoDB and NodeJS stack trying to do some simple conditional logic. Unfortunately, I am using the MongoDB native driver for NodeJS, and the owner of the project didnt choose to use Mongoose.
The below code is looking through my documents and filtering based on 'props': 'value' and sending a response via Express.
let cursor = db.collection('collection').find({props: 'value' })
cursor.forEach((doc) => {
if (!doc) {
return res.send('No document found with that property assigned!')
}
res.json(doc)
})
The method is working fine when the property is found, but Express hangs when the the value isn't found. Does anyone have any fixes?

It looks like the No document found ... condition will never be triggered. The if block is inside a section of code that will only be executed if the doc variable exists.
Try having the 'no results' condition be a default condition, or check for the cursor to contain documents.

Related

How to find multiple mongo db objects at once in node js

i am trying to run a search , it is working fine with findOne and recieving data but when i use find it just return some headers and prototypes like this
response i am getting
code
let data = await client
.db("Movies")
.collection("movies")
.find();
console.log(data);
please tell me where i am going wrong
Based on documentation
The toArray() method returns an array that contains all the documents from a cursor. The method iterates completely the cursor, loading all the documents into RAM and exhausting the cursor.
so just try
let data = await client
.db("Movies")
.collection("movies")
.find({}).toArray();
console.log(data);

Strapi & react-admin : I'd like to set 'Content-Range' header dynamically when any fetchAll query fires

I'm still a novice web developer, so please bear with me if I miss something fundamental !
I'm creating a backoffice for a Strapi backend, using react-admin.
React-admin library uses a 'data provider' to link itself with an API. Luckily someone already wrote a data provider for Strapi. I had no problem with step 1 and 2 of this README, and I can authenticate to Strapi within my React app.
I now want to fetch and display my Strapi data, starting with Users. In order to do that, quoting Step 3 of this readme : 'In controllers I need to set the Content-Range header with the total number of results to build the pagination'.
So far I tried to do this in my User controller, with no success.
What I try to achieve:
First, I'd like it to simply work with the ctx.set('Content-Range', ...) hard-coded in the controller like aforementioned Step 3.
Second, I've thought it would be very dirty to c/p this logic in every controller (not to mention in any future controllers), instead of having some callback function dynamically appending the Content-Range header to any fetchAll request. Ultimately that's what I aim for, because with ~40 Strapi objects to administrate already and plenty more to come, it has to scale.
Technical infos
node -v: 11.13.0
npm -v: 6.7.0
strapi version: 3.0.0-alpha.25.2
uname -r output: Linux 4.14.106-97.85.amzn2.x86_64
DB: mySQL v2.16
So far I've tried accessing the count() method of User model like aforementioned step3, but my controller doesn't look like the example as I'm working with users-permissions plugin.
This is the action I've tried to edit (located in project/plugins/users-permissions/controllers/User.js)
find: async (ctx) => {
let data = await strapi.plugins['users-permissions'].services.user.fetchAll(ctx.query);
data.reduce((acc, user) => {
acc.push(_.omit(user.toJSON ? user.toJSON() : user, ['password', 'resetPasswordToken']));
return acc;
}, []);
// Send 200 `ok`
ctx.send(data);
},
From what I've gathered on Strapi documentation (here and also here), context is a sort of wrapper object. I only worked with Express-generated APIs before, so I understood this snippet as 'use fetchAll method of the User model object, with ctx.query as an argument', but I had no luck logging this ctx.query. And as I can't log stuff, I'm kinda blocked.
In my exploration, I naively tried to log the full ctx object and work from there:
// Send 200 `ok`
ctx.send(data);
strapi.log.info(ctx.query, ' were query');
strapi.log.info(ctx.request, 'were request');
strapi.log.info(ctx.response, 'were response');
strapi.log.info(ctx.res, 'were res');
strapi.log.info(ctx.req, 'were req');
strapi.log.info(ctx, 'is full context')
},
Unfortunately, I fear I miss something obvious, as it gives me no input at all. Making a fetchAll request from my React app with these console.logs print this in my terminal:
[2019-09-19T12:43:03.409Z] info were query
[2019-09-19T12:43:03.410Z] info were request
[2019-09-19T12:43:03.418Z] info were response
[2019-09-19T12:43:03.419Z] info were res
[2019-09-19T12:43:03.419Z] info were req
[2019-09-19T12:43:03.419Z] info is full context
[2019-09-19T12:43:03.435Z] debug GET /users?_sort=id:DESC&_start=0&_limit=10& (74 ms)
While in my frontend I get the good ol' The Content-Range header is missing in the HTTP Response message I'm trying to solve.
After writing this wall of text I realize the logging issue is separated from my original problem, but if I was able to at least log ctx properly, maybe I'd be able to find the solution myself.
Trying to summarize:
Actual problem is, how do I set my Content-Range properly in my strapi controller ? (partially answered cf. edit 3)
Collateral problem n°1: Can't even log ctx object (cf. edit 2)
Collateral problem n°2: Once I figure out the actual problem, is it feasible to address it dynamically (basically some callback function for index/fetchAll routes, in which the model is a variable, on which I'd call the appropriate count() method, and finally append the result to my response header)? I'm not asking for the code here, just if you think it's feasible and/or know a more elegant way.
Thank you for reading through and excuse me if it was confuse; I wasn't sure which infos would be relevant, so I thought the more the better.
/edit1: forgot to mention, in my controller I also tried to log strapi.plugins['users-permissions'].services.user object to see if it actually has a count() method but got no luck with that either. Also tried the original snippet (Step 3 of aforementioned README), but failed as expected as afaik I don't see the User model being imported anywhere (the only import in User.js being lodash)
/edit2: About the logs, my bad, I just misunderstood the documentation. I now do:
ctx.send(data);
strapi.log.info('ctx should be : ', {ctx});
strapi.log.info('ctx.req = ', {...ctx.req});
strapi.log.info('ctx.res = ', {...ctx.res});
strapi.log.info('ctx.request = ', {...ctx.request});
ctrapi.log.info('ctx.response = ', {...ctx.response});
Ctx logs this way; also it seems that it needs the spread operator to display nested objects ({ctx.req} crash the server, {...ctx.req} is okay). Cool, because it narrows the question to what's interesting.
/edit3: As expected, having logs helps big time. I've managed to display my users (although in the dirty way). Couldn't find any count() method, but watching the data object that is passed to ctx.send(), it's equivalent to your typical 'res.data' i.e a pure JSON with my user list. So a simple .length did the trick:
let data = await strapi.plugins['users-permissions'].services.user.fetchAll(ctx.query);
data.reduce((acc, user) => {
acc.push(_.omit(user.toJSON ? user.toJSON() : user, ['password', 'resetPasswordToken']));
return acc;
}, []);
ctx.set('Content-Range', data.length) // <-- it did the trick
// Send 200 `ok`
ctx.send(data);
Now starting to work on the hard part: the dynamic callback function that will do that for any index/fetchAll call. Will update once I figure it out
I'm using React Admin and Strapi together and installed ra-strapi-provider.
A little boring to paste Content-Range header into all of my controllers, so I searched for a better solution. Then I've found middleware concept and created one that fits my needs. It's probably not the best solution, but do its job well:
const _ = require("lodash");
module.exports = strapi => {
return {
// can also be async
initialize() {
strapi.app.use(async (ctx, next) => {
await next();
if (_.isArray(ctx.response.body))
ctx.set("Content-Range", ctx.response.body.length);
});
}
};
};
I hope it helps
For people still landing on this page:
Strapi has been updated from #alpha to #beta. Care, as some of the code in my OP is no longer valid; also some of their documentation is not up to date.
I failed to find a "clever" way to solve this problem; in the end I copy/pasted the ctx.set('Content-Range', data.length) bit in all relevant controllers and it just worked.
If somebody comes with a clever solution for that problem I'll happily accept his answer. With the current Strapi version I don't think it's doable with policies or lifecycle callbacks.
The "quick & easy fix" is still to customize each relevant Strapi controller.
With strapi#beta you don't have direct access to controller's code: you'll first need to "rewrite" one with the help of this doc. Then add the ctx.set('Content-Range', data.length) bit. Test it properly with RA, so for the other controllers, you'll just have to create the folder, name the file, copy/paste your code + "Search & Replace" on model name.
The "longer & cleaner fix" would be to dive into the react-admin source code and refactorize so the lack of "Content-Range" header doesn't break pagination.
You'll now have to maintain your own react-admin fork, so make sure you're already committed into this library and have A LOT of tables to manage through it (so much that customizing every Strapi controller will be too tedious).
Before forking RA, please remember all the stuff you can do with the Strapi backoffice alone (including embedding your custom React app into it) and ensure it will be worth the trouble.

Firestore: get document back after adding it / updating it without additional network calls

Is it possible to get document back after adding it / updating it without additional network calls with Firestore, similar to MongoDB?
I find it stupid to first make a call to add / update a document and then make an additional call to get it.
As you have probably seen in the documentation of the Node.js (and Javascript) SDKs, this is not possible, neither with the methods of a DocumentReference nor with the one of a CollectionReference.
More precisely, the set() and update() methods of a DocumentReference both return a Promise containing void, while the CollectionReference's add() method returns a Promise containing a DocumentReference.
Side Note (in line with answer from darrinm below): It is interesting to note that with the Firestore REST API, when you create a document, you get back (i.e. through the API endpoint response) a Document object.
When you add a document to Cloud Firestore, the server can affect the data that is stored. A few ways this may happen:
If your data contains a marker for a server-side timestamp, the server will expand that marker into the actual timestamp.
Your data data is not permitted according to your server-side security rules, the server will reject the write operation.
Since the server affects the contents of the Document, the client can't simply return the data that it already has as the new document. If you just want to show the data that you sent to the server in your client, you can of course do so by simply reusing the object you passed into setData(...)/addDocument(data: ...).
This appears to be an arbitrary limitation of the the Firestore Javascript API. The Firestore REST API returns the updated document on the same call.
https://firebase.google.com/docs/firestore/reference/rest/v1beta1/projects.databases.documents/patch
I did this to get the ID of a new Document created, and then use it in something else.
Future<DocumentReference<Object>> addNewData() async {
final FirebaseFirestore _firestore = FirebaseFirestore.instance;
final CollectionReference _userCollection = _firestore.collection('users');
return await _userCollection
.add({ 'data': 'value' })
.whenComplete(() => {
// Show good notification
})
.catchError((e) {
// Show Bad notification
});
}
And here I obtain the ID:
await addNewData()
.then((document) async {
// Get ID
print('ID Document Created ${document.id}');
});
I hope it helps.

After successful db.collection.update always error is thrown

Am using Node.JS to update my collection data based on a logic.
The update happens as expected but in my console after the update it is not returning proper values. It is always returning errors. Below is the code snippet
db.collection('test').update(query,operator,options,function(err,docs){
if(errs) {
console.log('something went wrong somewhere');
}
});
The above snippet always prints something went wrong somewhere. Does that mean that the update is not successful.
I use MongoClient along with Node.js.
P.S: Newbie to MongoDB learning via 10gen courses

How do I save an updated CouchDB doc with Evently?

I'm following IBM's tutorial on CouchDB and ran into a problem saving edited documents. Saving a new doc works fine, and it looks like all my existing doc's values (retrieved via the openDoc function) are valid, but the new values are simply not taking.
As I trace through the executing code, it looks like the new values are there:
However, after saveDoc returns successfully (strange!), the doc is not updated. If I log the updated doc, the logged object has no _id or _rev values, though you can clearly see they were present while saving (see first screenshot).
Is there some nuance of saveDoc, or perhaps Evently, that I'm not understanding?
In your success callback, you are not logging the updated document, your are logging the newdoc object from line 87 (minus it went through the saveDoc function, which apparently undefined _id and _rev, but that's ok).
The success callback can have an argument that is the response from the server. If you write :
success: function(data) {
console.log(data);
}
you should see in the response a new _rev starting with 2-.
If you really want to see the full doc once updated, just call openDoc from your success callback to get the updated version.
Other detail, when you say
saveDoc returns successfully
I think you meant that the success callback is called, because saveDoc is asynchronous and should return instantly anyway.

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