I want to serialize my Sounds model for use in my game.js file. This is what I have.
views.py
def index(request):
context = {'sounds': serializers.serialize('json', Sounds.objects.all()) }
return render(request, 'index.html', context)
index.html
<button type="submit" onclick="main()">Let's Start!</button>
game.js
function main(){
var data = {{ context|safe }};
// print all objects here
}
It's not working - not sure what the issue is. Basically, when I click the button in index.html, it should go to the main function (this part works), and then set a variable data with the objects in the model so that I can use it. Also, is it possible to filter objects in data so that I have a list with only the objects with id = 1? I want to do this in game.js (not in views.py or elsewhere).
It's hard to tell what the exact problem with the serialiser is without an actual error log. If you can actually open the console that django is running in, it should display the error when it occurs. From that a better diagnostic of the issue can be made. It would be wise to do this in the future otherwise questions like this will be downvoted.
Yes, you can filter arrays in Javascript using the filter function. The function creates a new array by interating through the objects in the array that will be passed into a function, which should return true if it should exist in the new array or false it is shouldn't.
So for the example you provided, it would appear as so:
sounds = sounds.filter((sound) => { sound.id === 1; });
Note you will have to assign the new array, the original array will not change bu running the function itself.
I highly recommend you search for solutions to these problems yourself before creating threads on Slack Overflow or your reputation will quickly decrease.
Related
Ive looked related posts and couldn't quite find what I was looking for.
So I am build a backend rest api and I have certain tests I am collecting data on. The tests have their own models, and these models are associated with collections (obviously).
So I have a separate controller for each model. Now I have a "job" controller which queries data from each separate test. Now I have a separate script where I store these model objects in an JSON object. I am wondering how I can access these models properly (I am close but cant quite assign properly). Here is the block:
const testMappings = {
'aprobe':aprobe,
'status':status,
//'rxserial':rxserial,
}
Now when I try assignment as follows, where testMappings is the imported script variable:
const testMappings = activeTests.testMappings;
console.log(testMappings['aprobe']);
I get the following output:
Model {aprobe}
I would like to access the actual aprobe object. Also if anyone knows a better way of dynamically assigning these (instead of having bunch of if statements ie if(name == 'aprobe').... do something), it would be much appreciated.
You are probably looking for something like below :
const name = 'aprobe';
Object.keys(testMappings).indexOf(name) > -1 ? testMappings[name] : null
the above should give you: Model {aprobe}
So basically if the key exists in your object then you'd like to fetch the value of that key which would give you your model dynamically.
Problem
Hello to all,
Given the example code:
<Table
data1={data}
data2={columns}
/>
I've to pass data.property to columns,
I will get data.property after a successful call to a remote server, so initially data will be simply null.
I've the data inside columns displaying in this way:
const columns = [
function() {data.property ? doThis : doThat },
{object1},
{object2},
{object3},
....
]
Consideration
I cannot change the order or the dimension of the column, so I cannot merge the two objects and the const columns is in another file than the starting table.
We are using ReactTable.
Why do I need the property of Data?
I need it to do a check inside the function inside columns,
something like this:
data.property.length ? DoThis : DoThat
My Tries
I tried to merge the two object in a new one, but I messed up everything and broke my table.
By the nature of your question, it appears you require to use onFetchData() to ensure all data is present before rendering the view.
An example of this type of usage is detailed within the npm documentation usage examples for the react-table project
This is the preferred method, I am familiar with the concept writing APIs in Express, where it is required that you use the async package along with a series of functions in order to ensure all data has been generated before the callback provides the data to your view being rendered.
Hopefully this fishing rod helps you in the right direction!
If this suggestion helps you, please do edit your question and share the solution you have written to tackle the issue so future viewers of this question can also benefit.
Not sure if I understand your question correctly, but I can imagine that your code crashes due to either data or data.property being undefined, as it is still waiting for your asynchronous API call to finish.
In order to prevent this you could do the following:
( data && data.property && data.property.length ) ? DoThis : DoThat
I'm making a web app with Angular however I'm having trouble with the load button. So the user presses the load button, selects a save to load, and a new set of properties is loaded into forms that each constitute a step-item in a stepper. The forms array that loads all of the forms is 'reset' with this function:
private resetPropForms(): void {
this.propForms = [];
}
This is the function that receives as an argument a properties event and then sets the forms array:
onPropertiesEmitted(properties: Property[]): void {
this.resetPropForms();
this.resetDividedProperties();
this.resetUndividedProperties();
this.setDividedProperties( properties );
this.setForms();
this.setUndividedProperties( properties );
}
And this is what my template looks like:
<se-stepper
*ngIf="undividedProperties"
[linearMode]="false"
[(activeStepIndex)]="activeStepIndex"
>
<se-step-item
*ngFor="let form of propForms"
>
<app-properties-form
[propertiesForm]="form"
(change)="onPropertiesChanged($event)"
>
</app-properties-form>
</se-step-item>
</se-stepper>
Lastly, the view is updated but only after I go to the next step and come back. And if I save the properties then the correct value is sent to the backend even though the value displayed in the view is incorrect/not updated. Any ideas why this is happening. I tried using trackBy with a unique identifier for each form ( using a random number ) but that didn't work. I tried using ChangesRef and detectChanges() and that didn't work. When I leave out the *ngFor and just display the first form in the array it updates properly so that leads me to believe that this problem has something to do with the *ngFor.
edit:I'm pretty sure setTimeout() placed in onPropertiesEmitted() worked but I forgot where I put it to make it work and it seemed like a not-so-great solution to the problem
I Think the problem is that the array is the same and change detect won't detect changes, try this
private resetPropForms(): void {
//this.propForms = [];
//array.slice() returns new array
this.propForms = this.propForms.slice(0,0);
}
You could also reset the form before assigning new properties ( form.reset() )
I have an AngularJS application that manages badges. In the application is a form to set the badge # and the name of the person it is assigned to, etc. This gets stored in $scope.badge.
When the user submits the form, I want to add the new badge to a list of badges, which is displayed below the form.
Partial code looks like this:
var badge = angular.copy($scope.badge); // make a copy so we don't keep adding the same object
$scope.badgeList.push(badge);
The first time I run this code, it adds the badge as expected.
Any subsequent time I run this code, the next badge REPLACES the previous badge in the badgeList. In other words, if I add 5 badges, the badgeList still only has 1 object in it because it just keeps getting replaced.
I'm thinking that this may be happening because the same object keeps getting added? Maybe I'm wrong? I am using angular.copy to try and avoid that happening, but it doesn't seem to be working.
Any thoughts on this?
$scope.badgeList.push(($scope.badge);
console.log($scope.badgeList)
no need to use angular.copy since you are ultimately storing all the badges in an array
angular.copy is used when you want to make a clone of object and not update the existing object and the clone's change are not reflected in main object.
If you just want to maintain a list of badges you can execute this block of code
like this
function addBadges(){
$scope.badgeList.push(($scope.badge);
console.log($scope.badgeList)
}
If you are refreshing the controller then obviously the variable will be reset and for such a case you need to make use of angular services.
Create a service and inside the service you need to define getter and setter method that will help in data persistence
and your bages array if saved in service will persist till the application is in foreground.
You could do something like this.
function addBadges(){
//initialize if undefined or null
if(!$scope.badgeList){
$scope.badgeList = [];
}
//Check if badge does not exists in the list
if ($scope.badgeList.indexOf($scope.badge) === -1) {
//Add to badge list
$scope.badgeList.push($scope.badge);
}
}
I am making a project with Meteor and I'm having some issues trying to get data out of mongodb in JavaScript. I have the following in a function:
console.log(Time.find({today: "Saturday"}).fetch());
In my publish.js file on the server side I have the following:
Meteor.publish("time", function () {
var currentUserId = this.userId;
return Time.find({user: currentUserId});
});
And In my subscriptions file I have the following:
Meteor.subscribe("time");
This function gets called later down in the code but it returns an empty array. If I run this code in my browsers console it returns an array with 2 objects in it, which is correct. This leads me wondering if I can use the .fetch() function from within my code? As if I leave off the .fetch() it returns what looks like the usual giant object. My real problem is I need the data in the form that .fetch() gives it to me in. I think it's because the function gets triggered before the data gets a chance to load in, as if I switch out the .fetch() for a .count() it returns 0.
Is there any way around this or a fix?
Where are you you running that console.log?
There are a couple fundementals here that I believe you may have glossed over.
1 Pub / Sub
This is how we get data from the server, when we subscribe to a publication i becomes active and begins to send data, this is neither instant or synchronous, (think of it more like turning on a hose pipe), so when you run your console.log, you may not yet have the data on the client.
2 Reactive contexts
One of the fundamental aspects to building anything in meteor is its reactivity. and it helps to start thinking in terms of reactive and non reactive contexts. A reactive context is one that re-runs each time the data it depends on changes. Using an autorun (Tracker.autorun or this.autorun insdie a template lifecycle callback) or a template helper are good examples. By placing it in a template helper it will re-run when the data is available.
Template.Whatever.helpers({
items: function() {
// ...do your find here.....
}
});
As items is a reactive context, depending on the collection data, it re-run when that changes, giving you access to the data when the client has them.
3 Retrieving Non Reactive Data
Alternatively it is also possible to retrieve data non-reactively by using Meteor.call with a meteor method, and then doing something with the result, in the callback to the Meteor.call. Depending on what you're doing, Meteor.wrapAsync may also be your friend here.
a simple example (out of my head, untested) :
// on the server
Meteor.methods({
gimmeStuff: function() {
return "here is your stuff kind sir!";
}
});
// on the client
Meteor.call('gimmeStuff', function(err, result) {
if (err || !result) {
console.log("there was an error or no result!");
return false;
}
console.log(result);
return result;
});
4 Its Unlikely that you actually need ithe .fetch()
If you're working with this in a template, you don't need a fetch.
If you want this to be non-reactive you don't need a fetch
As one of the commenters mentioned, a cursor is just a wrapper around that array, giving you convenient methods, and reactivity.
5 Go Back to the Begining
If you haven't already, I would highly recommend working through the tutorial on the meteor site carefully and thoroughly, as it covers all of the essentials you'll need to solve far more challenging problems than this, as well as, by way of example, teach you all of the fundamental mechanics to build great apps with Meteor.