Pass arrays from django to js with ajax - django

Question

I'm trying to pass 2 arrays via ajax from my views to my javascript. When I console.log my arrays i get 2 empty ones. I feel like I know what the error is but I can't solve it. I'm going to include my code first, than my toughts.
views.py:
In my first method, I want to pass my data to 2 arrays (dates,weights). In get_data is where I want to send my data to js.
from django.shortcuts import render
from django.contrib import messages
from django.contrib.auth.models import User
from django.http import JsonResponse
from django.shortcuts import get_object_or_404
from users import models
from users.models import Profile
from .forms import WeightForm
import json
dates = []
weights = []
dates_queryset = []
def home(request):
form = WeightForm()
if request.is_ajax():
profile = get_object_or_404(Profile, id = request.user.id)
form = WeightForm(request.POST, instance=profile)
if form.is_valid():
form.save()
return JsonResponse({
'msg': 'Success'
})
dates_queryset = Profile.objects.filter(user=request.user)
dates = dates_queryset.values_list('date', flat=True)
weights = dates_queryset.values_list('weight', flat=True)
return render(request, 'Landing/index.html',{'form':form})
def get_data(request, *args,**kwargs):
data = {
'date': dates,
'weight': weights
}
return JsonResponse(data)
url:
url(r'^api/data/$', get_data, name='api-data'),
Ajax call:
var endpont = '/api/data'
$.ajax({
method: 'GET',
url: endpont,
success: function(data){
console.log(data);
},
error: function(error_data){
console.log("Error");
console.log(error_data);
}
})
Js console.log output:
{date: Array(0), weight: Array(0)}
My toughts:
I think I need to pass both of my arrays to the context, but if I try to pass them like this {'form':form, 'dates':dates, 'weights':weights'} then I get an error that they are referenced before use. I saw another question on Stackoverflow where they put more than 1 value to the context like this.

Answer 1

Your get_data view is doing exactly what it is supposed to.
You've defined the dates and weights arrays in the global scope, and the home view is not changing those global variables, even though they are named the same thing. See this link for a simple demonstration. Python Global Variables
If you use the global keyword in front of "dates" and "weights" in the home view, then those variables would be updated, and get_data should return the populated arrays.