Updating model field after input in Django - django

Question

I am trying to update an account value model field after the user inputs a stock price and quantity from a form. Essentially the user would input a stock price and share quantity and their account balance should reflect the purchase amount. Below are images of my models.py, my forms.py, my views.py and my buy_stock.html page. Any insight as to how I can get the value to save would be very helpful. Thanks in advance. - Total newb
Views.py
from django.shortcuts import render, redirect
from .models import Stock, Bank, BuyStockModel
from .forms import StockForm, BankForm, BuyStock, Registration
from django.contrib import messages
import requests
import json
def main(request):
stocks = BuyStockModel.objects.all().order_by('-created')
form = BuyStock()
account = Bank.objects.only('account')
balance = account
if request.method == 'POST':
price = request.POST.get('price')
quantity = request.POST.get('quantity')
if price is not None:
price = float(price)
if quantity is not None:
quantity = float(quantity)
total = float(price) * float(quantity)
if balance >= total:
balance = balance - total
account.update(account = balance)
#account.save()
ticker = request.POST['ticker']
api_request = requests.get(
"https://cloud.iexapis.com/stable/stock/" +
ticker +
"/quote?token=i_should_get_a_new_one"
)
try:
api = json.loads(api_request.content)
except Exception as e:
api = "Error..."
context = {
'api': api,
'form' : form,
'stocks' : stocks,
"account" : account
}
return render(request, 'buy_stock.html', context)
else:
context = {'form' : form, 'stocks' : stocks}
return render(request, 'buy_stock.html', context)
def buy_stock(request):
print('buy_stock')
if request.method == 'GET':
form = BuyStock()
stocks = BuyStockModel.objects.all().order_by('-created')
output = {'form' : form, 'stocks' : stocks}
return render(request, 'buy_stock.html', output)
elif request.method == 'POST':
form = BuyStock(request.POST or None)
if form.is_valid():
form.save()
name = form.cleaned_data['name']
price = form.cleaned_data['price']
quantity = form.cleaned_data['quantity']
form = BuyStock()
return redirect('buy_stock')
return render(request, 'buy_stock.html', {
'form' : form,
'name' : name,
'price' : price,
'quantity' : quantity
})
Models.py
from django.db import models
class Stock(models.Model):
ticker = models.CharField(max_length = 10)
def __str__(self):
return self.ticker
class Bank(models.Model):
account = models.DecimalField(
max_digits = 15, default = 30000.0, decimal_places = 0,
editable = True
)
def __str__(self):
return self.account
class BuyStockModel(models.Model):
name = models.CharField(max_length = 100)
option = models.CharField(max_length = 10, default = 'buy')
price = models.DecimalField(
max_digits = 15, decimal_places = 2, default = 0
)
quantity = models.DecimalField(
max_digits = 15, decimal_places = 0, default = 0
)
total_value = models.DecimalField(
max_digits = 15, default = 1, decimal_places = 0,
editable = True
)
created = models.DateTimeField(auto_now_add = True)
def __str__(self):
return self.price
def __str__(self):
return self.quantity
def calc_total(self):
amount = (self.price * self.quantity)
return amount
def save_total(self):
self.total_value = self.calc_total()
super(BuyStockModel, self).save()
Forms.py
from django import forms
from .models import Stock, Bank, BuyStockModel
from django.contrib.auth import login, authenticate
from django.contrib.auth.forms import UserCreationForm
from django.contrib.auth.models import User
class Registration(UserCreationForm):
email = forms.EmailField()
class Meta:
model = User
fields = ["username", "email", "password1", "password2"]
class StockForm(forms.ModelForm):
class Meta:
model = Stock
fields = ["ticker"]
class BankForm(forms.ModelForm):
class Meta:
model = Bank
fields = ["account"]
class BuyStock(forms.ModelForm):
class Meta:
model = BuyStockModel
fields = ["name", "price", "quantity"]
widgets = {
'name' : forms.TextInput(attrs = {'class' : 'form-control'}),
'price' : forms.TextInput(attrs = {'class' : 'form-control'}),
'quantity' : forms.TextInput(attrs = {'class' : 'form-control'}),
}
buy_stock.html
{% extends 'base.html' %}
{% block content %}
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Project-4 Buy Stock page</title>
</head>
<body>
<div class="container"></div>
<h1>Buy Stock</h1>
<br/>
<div>
<form action = "{%url 'main' %}" class="form-inline my-2 my-lg-0" method = "POST">
{% csrf_token %}
<input class="form-control mr-sm-2" type="search" placeholder="Get Stock Quote" aria-label="Search" name = "ticker">
<button class="btn btn-outline-secondary my-2 my-sm-0" type="submit">Stock Quote</button>
</form>
</div>
<br/>
<br/>
<div>
{% if ticker %}
{{ ticker }}
{% endif %}
{% if api %}
{% if api == "Error..." %}
There was a problem with your ticker symbol,
please try again...
{% else %}
<h2>{{ api.companyName }}</h2>
<br/>
{% load humanize %}
Price: ${{ api.latestPrice|intcomma }}<br/>
Previous Close: ${{ api.previousClose|intcomma }}<br/>
Market Cap: ${{ api.marketCap|intcomma }}<br/>
YTD Change: {{ api.ytdChange }}<br/>
52 Week High: ${{ api.week52High|intcomma }}<br/>
52 Week Low: ${{ api.week52Low|intcomma }}<br/>
<br/>
{% endif %}
{% else %}
{% endif %}
</div>
<br/>
<div>
<h6 class = "bold">Total in Account</h6>
{% for item in account %}
{% load humanize %}
<h1 class = "bold">${{ item.account|intcomma }}</h1>
{% endfor %}
</div>
<div class="container">
<div class="row">
<div class="col-sm">
<div class = "form-group">
<form action = "{%url 'buy_stock' %}" method = "POST">
{% csrf_token %}
{{ form.as_p }}
<div class="dropdown">
<div class="dropdown">
<button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenu2" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Trading Options
</button>
<div class="dropdown-menu" aria-labelledby="dropdownMenu2">
<button class="dropdown-item" type="sumbit">Buy</button>
<button class="dropdown-item" type="submit">Sell</button>
</div>
</div>
</form>
</div>
</div>
<div class="row">
<div class="col-sm">
<table class="table table-striped table-bordered table-hover">
<thead class="thead-dark">
<tr>
<th scope="col">Date Purchased</th>
<th scope="col">Company Name</th>
<th scope="col">Stock Price</th>
<th scope="col">Shares Purchased</th>
</tr>
</thead>
<tbody>
{% for item in stocks %}
<tr>
{% load humanize %}
<th scope="row">{{ item.created }}</th>
<td>{{ item.name }}</td>
<td>${{ item.price|intcomma }}</td>
<td>{{ item.quantity|intcomma }} Shares</td>
</tr>
{% endfor %}
</tbody>
</table>
<br/>
{% for item in stocks %}
<a class="btn btn-danger" href = "{% url 'sell_stock' item.id %}">Delete {{ item.name }}</a>
{% endfor %}
</div>
</div>
</div>
</div>
</div>
<br/>
<br/>
<br/>
</body>
{% endblock %}

Answer 1

I think you should learn first about model relations. You data model will not work this way and fixing that, the rest will become more clear, hopefully.
An Order (you call it BuyStockModel) is the marriage of a product with a customer. So this order model should have links with the product (Stock) and the Customer (in your case represented by their Bank account). A broker has 2-way orders: both sales and purchase orders, but for the basic data model it's not important.
I'm going to use Order below, because BuyStockModel is not a good name for me :).
So you need two relations:
Order
/ \
Stock Bank
Django uses ForeignKeys for this relation:
class Order(models.Model):
stock = models.ForeignKey(Stock, on_delete=models.PROTECT)
account = models.ForeignKey(Bank, on_delete=models.PROTECT)
option = models.CharField(max_length = 10, default = 'buy')
price = models.DecimalField(
max_digits = 15, decimal_places = 2, default = 0
)
quantity = models.DecimalField(
max_digits = 15, decimal_places = 0, default = 0
)
created = models.DateTimeField(auto_now_add = True)
#property
def total_value(self):
return self.price * self.quantity
def __str__(self):
return (
f"{self.option.upper()}: {self.id} / qt: {self.quantity}"
f" / price: {self.price}"
)
You can now construct a single "OrderForm" using the Order model, that can render the accounts and stock tickers. That should get you on your way.