I'm creating a configurator app for heating systems. Essentially the idea is by putting in a few inputs - the app will spit out the part number for a system pack where a user can see a detailed bill of material (BOM).
One key element is the output where we need to show a few options. I.e. if someone needs a 200kW system, there could be 3-4 packs that are suitable (190kW -210kW might be more cost effective).
I want in the first instance to show on a route the pack options that are suitable- then the user selects the pack they want- which takes you to a route (/cart) which shows the BOM.
I have put in input variables min and max which searches a database cascades.db. This successfully shows me the table of options.
from cs50 import SQL
from flask import Flask, render_template, request, url_for, redirect
app = Flask(__name__)
db = SQL("sqlite:///cascades.db")
@app.route("/")
def index():
return render_template("index.html")
@app.route("/search", methods=["GET", "POST"])
def search():
output = request.form.get("output")
hydraulic = request.form.get("hydraulic")
layout = request.form.get("layout")
controls = request.form.get("controls")
min_output = int(output) - 15
max_output = int(output) + 15
cascades = db.execute("SELECT * FROM cascades WHERE hydraulic = ? AND layout = ? AND output BETWEEN ? and ?", hydraulic, layout, min_output, max_output)
return render_template("search.html", cascades=cascades)
@app.route("/cart", methods=["GET", "POST"])
def cart():
bom_id = request.form.get("bom_id")
bom = db.execute("SELECT * FROM bom WHERE bom_id = ?", bom_id)
return render_template("bom.html", bom = bom)
When running the app- the first bit works - i.e. it shows me a list of all the packs that meet the criteria- but when clicking the 'Choose' button Im getting stuck.
{% extends "layout.html" %}
{% block body %}
<h3> Boiler Cascade Pack Options:</h3>
<table class="table table-striped table-boardered">
<tr>
<th>Part Number</th>
<th>Description</th>
<th>Number of boilers</th>
<th>BOM</th>
</tr>
{% for cascades in cascades %}
<tr>
<td scope="cascades">{{ cascades["id"] }}</td>
<td>{{ cascades["description"] }}</td>
<td>{{ cascades["number_of_boilers"] }}</td>
<td>
<form action "/cart" method="post">
<input name="bom_id" type="hidden" value="{{ cascades["id"] }}">
<input class="btn btn-primary" type="submit" value="Choose">
</form>
</td>
</tr>
{% endfor %}
</table>
{% endblock %}
But when submitting the form- where they select the pack (which has the pack id number- as a hidden form) I get the following error:
File "/home/ubuntu/cascade2/application.py", line 26, in search
min_output = int(output) - 15 TypeError: int() argument must be a
string, a bytes-like object or a number, not 'NoneType'
It seems like the route is trying to use the same logic in the second search but at this point its redundant. The second search all I want is to show me information where the Pack id = BOM.
I've noticed the URL stays on the (/search) route with this and not going to the (/cart).
I've tried several things such as putting in a IF NOT output- redirect to Cart to try and bi pass this- which successfully loads the bill of material page but nothing comes up as I don't think its posted the id to the route.
I've also changed it to GET instead of POST, which results in the query string /search?bom_id=71723827132. Which shows its picking up the part number- but staying on the /search route where I see the error.
<h3> Boiler Cascade Pack Options:</33>
<table class="table table-striped table-boardered">
<tr>
<th>Part Number</th>
<th>Description</th>
<th>Number of boilers</th>
</tr>
{% for cascade in cascade %}
<tr>
<td scope="cascade">{{ cascades["id"] }}</td>
<td>{{ cascades["description"] }}</td>
<td>{{ cascades["number_of_boilers"] }}</td>
</tr>
{% endfor %}
</table>
<br>
<h4>Bill of material:</h4>
<br>
<table class="table table-striped table-boardered">
<tr>
<th>Product ID</th>
<th>Product Description</th>
<th>Quantity</th>
</tr>
{% for bom in bom %}
<tr>
<td scope="bom">{{ bom["part_number"] }}</td>
<td>{{ bom["product_description"] }}</td>
<td>{{ bom["quantity"] }}</td>
</tr>
{% endfor %}
</table>
Been stuck on this for a month. This to me is the last piece of the puzzle. Any help/suggestions would be great. I'm new to programming so I bet I've missed something obvious :)
