I have a jade template where I'm printing out properties from a mongoose object. The object has properties that were populated via mongoose's dbref-like populate feature. When The template renders I get nonsense.
simplified example:
in the route
User.findById(req.params.user, function(err, user){
res.render('training', {training:user.training});
}).populate('training.details');
in the template:
a.training-link(href='/training/#{training.details.id}') ...
in the browser:
...
The first time the page is loaded, where I would expect a regular mongo hexadecimal string (4fac4e5f379cb0a68100015d) I get something like "O >°Cm5�". This only happens on the first page load after a server restart. All subsequent page loads render as expected.
What's happening here and how can I fix it?
Thanks.
This is a bit embarrassing but I figured it out.
There is a logical branch in our app that, for various reasons, causes the code in my question above to run on the second and subsequent loads but not on the first. The other branch, which only runs on the first load, makes a similar query but I hadn't added populate('training.details') to it. I believe the nonsense string O¬N_7°¦� is the result of calling .id on an ObjectId object rather than the populated training.details.
Looks like we need to refactor some code.
Related
This is just a general question but I can provide an example if necessary. I've been working on a MongoDB/Mongoose, Node.JS, Express, and Handlebars stack app recently and I've ran into some issues with what is being passed from my route to the client side when dealing with Mongoose .find() queries.
I prefer to async await my queries. I have a deeply nested populate query that brings in all the data I need into one object. This is a very simplified breakdown of what I do
async function() { const finalObject = await Model.find({}).populate([*alot more populates*]) }
I pass this into my res.render() route, as so:
res.render('index', { finalObject });
The majority of my experience has been pretty straight forward. I have one issue in a separate stack overflow question about populating the same model twice in one chain (at different levels). I won't address that here.
I decided to do some calculations before passing the object to the route and attach some new values to the properties of the documents. This is where things get weird. I do some calculations and add new properties to documents (these properties are not part of the Schema). When the object is passed to the client-side, those properties I added are available to use (no problem here).
I needed to decode the finalObject into JSON and pass it as JSON as well for an easy use of the data in my client side JavaScript encodedFinalObject = encodeURIComponent(JSON.stringify(finalObject));
I decode it on the client side: clientSideFinalObject = JSON.parse(decodeURIComponent(encodedFinalObject)); and the properties I added are not there!
I'm wondering, how could the new properties I added pass through when I send the object but not pass through when I send the JSON? The decoding is the last thing I do before rendering the page, so it's not a matter of not having my code in the wrong order. I add the properties to the object then decode it.
Some research led me to find out that Model.find({}) does not return a native JavaScript object, but instead a Query. I'm assuming this is a user-defined class data-type that has special behaviors. My assumption is that between the passing from the back-end to the front-end, there is some middle step where the Query does its final processing.
The opposite situation has also occurred. As a solution to this, I decoded the Query finalObject immediately after the Model.find({}) and re-encoded it into a native JavaScript object. After that, I did all my calculations, attached the results as properties to the documents, and sent that new version over as the main finalObject (I still also sent over a separate decoded object for client-side JavaScript use).
This solved the issue of the new properties not being there. They appeared, but this time the decoded then re-encoded finalObject did not have the virtual properties of my Models. The main model has a virtual property that calculates some of it's other properties. It's almost as if that part of the query didn't execute within the .find({}) process. So, when I decoded the finalObject, the virtual properties were never there and were never decoded.
Can anyone explain to me what is going on? Thank you!
I am using node.js as a scripting language and I am also using nunjucks as the template engine. I have a weird situation going where some of the data that I retrieve from the MongoDB database is not being printed into document.
As you see hear these are the values that I want to print to the web page
But when you look at the web page, only some of the data has been printed out and the other information is missing.
I console.logged the data to prove that the values are in the database
A weird thing is that if you write the whole object into the code, like so
It will output all the data in one block. That includes the month, the year, and slug property that I am trying to output to the page. Yet, it only does that if I print out the whole object
I found out what was the problem. In my mongoose schema, I did not have the properties listed like slug, month, or date. So when I tried to retrieve data from those properties it did not output them. So If you are having similar problems make sure the properties are declared in your mongoose schema
I am working on an application that uses MongoDB for data persistence, alongside the mongoose library to allow angularjs to communicate with it. I'm using Postman to test my routes, and that's where the problem comes in.
In MongoDB, I inserted an entry thusly:
db.posts.insert{{id:6, author:"Blah", area:"Sport", body:"bleh", user_id:6, comments:[{author:"foo", body:"bar"}]})
I then queried it through Postman, and it successfully returned the Post, but there was a problem. The comments array had been returned as a strange data type, object Object, and I could not access it from my HTML files.
This is what Postman retrieved:
{"_id":"5536112cffc7bf00b2585d24","id":6,"author":"Blah","area":"Sport","body":"bleh","user_id":6,"comments":["[object Object]"]}]
I want to be able to access the author and body elements of comments independently, or else to be able to get at them from my http files. Does anyone know how I might stop this Object-ification from happening, or failing that, how I might query the data from this new Object?
Thanks.
Instead of passing complete db object we can pass required parameters. below is the example to form the required parameters.
res.json({"author":item.author,"body":item.body});
Here You can find call back function and array conversion from the cursor
I'm building an app in Express. In one of the views a logged in Superadmin is able to view all available clients/user. In this view I am loading a bunch of client data from my MongoDB/Mongoose with a simple:
app.get('/superadmin', function(req, res) {
Client.find({}, '_id company monthly_cost sms_cost', function (err, docs) ...
As you can see above i have choosen only the values that I need from the query. These four are: "_id", "company", "monthly_cost" and "sms_cost"
From the "_id" i can get a "creation date" by using .getTimestamp(), but the Dateobject this function return is bit to complex formated. I need a simpler date, something like: (YYYY-MM-DD). Im thinking of using a small node plugin like dateformat or possibly writing a very simple function that extract the YYYY, MM and DD from the IsoDate object and saving this in a new variable/array
Now to my questions:
Q1) WHERE is actually the right place for this code? I'm currently putting it inside the route handler above... consequently it will follow right below the code above. I'm thinking this is principally the right way according to a MVC pattern. I'm thinking I dont want to put this code in the Jade view template?
Q2) IN WHAT FORM should i save this data and HOW should i pass it along to Jade. Should I somehow add it to the "docs"-data... that is, the data I extract from my DB. Or should I rather put this creationDate in a separate array which i pass to jade side by side with the original DB-data.
I hope my questions are clear enough!
Q1:
If your Mongoose-query is solely dependent on your route /superadmin, this is exactly the right place to put your code. If you are using the same snippet in different routes or functions you might as well wrap it in a function that is accessible to every route in question. But don´t forget to also wrap req, res and other required variables. Have your calculations within your callback and use Jade only for representation of data.
Q2:
What do you mean by "save"? When you are already iterating over every document to do your calculations and transformations, create an extra field creationDate for every document and pass docs as a single parameter to the Jade file afterwards.
I have question regarding session.evaluate in SSJS. In a keyword document I have some #formula stored which does some conversion of data. Lets say this is would be:
#left(fieldname;2)
If the fieldname contained 'hello' this would result in 'he'. Nothing to fancy here. Now I would like to use this in an xpage.
I wrote a function called executeFormula(doc). I call this function from an action on a xpage. This xpage contains 1 notes document datasource. The function call is
executeFormula(datasource.getDocument(true))
Now for some reason the #formula is never calculated correctly. Do I need to save the document first before I can use session.evaluate(kwFormula,doc) or is the #formula wrong in some way?
p.s. I forgot to mention that this code is working inside a customvalidator
Without seeing the code for the executeFormula(doc) function it is very difficult to know exactly how session.evaluate is being called.
I would suggest taking the function out of the equasion for the moment and create a simple test page with the document source and a simple computed field with the session.evaluate in it so that you can see the result. Given your examples above the computed field would be something along the lines of
session.evaluate("#Left(fieldname;2)",xspDoc.getDocument(true));
Once you get acceptable results back then you can move it into your function and verify that it is working there also.
Don't forget that session.evaluate returns a vector so you may beed to do a .getFirstElement() on the returned value if it is not null.
If you're using it in a custom validator, the values posted from the browser/client haven't updated the data model (in your case, the document) yet. This happens after validation is successful.
I imagine it might work for some fields (e.g. fields that are updated after a successful refresh, or stored fields in an existing document).
Actually no need of mentioning the document, eg:- session.evaluate("#username") is enough.
For yours session.evaluate("#left('hello';2)") will work.,