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ViewsCannot get the value of an old (previous) cart
I want to "overwrite" my cart. So I get the information I want but the problem is I can't get the information of my old cart. I don't get it how it cannot be properly retrieved. And whole the time I'm getting quantity of 1.
Here is the app.post request:
app.post("/add-to-cart/:id", async (req, res) => {
try {
// fetch your data
const id = req.params.id,
{ data } = await axios.get("http://localhost:4200/products"),
singleProduct = await data.find((product) => product._id === id);
// create/get a cart
let cart;
if (!req.session.cart) {
req.session.cart = cart = new Cart({});
} else {
// req.session does not save the Cart object, but saves it as JSON objects
cart = new Cart(req.session.cart ? req.session.cart : {});
}
console.log("This is variable cart: ",cart)
cart.addProduct(singleProduct);
res.redirect("/");
console.log(req.session)
} catch (error) {
console.log(error);
}
});
It seems that something is wrong here: let cart = new Cart(req.body.cart ? req.body.cart : {});
So this is the console.log output:
This is the Cart code:
module.exports = function Cart(oldCart) {
this.productItems = oldCart.productItems || {};
this.totalQty = oldCart.totalQty || 0.00;
this.totalPrice = oldCart.totalPrice || 0.00;
this.addProduct = function(item) {
let storedItem = this.productItems;
if (!storedItem){
storedItem = this.productItems = {item: item, qty: 0, price: 0};
}
else{
storedItem.qty++;
this.totalQty ++;
storedItem = {item: item, qty: storedItem.qty, price: storedItem.price}
storedItem.price = storedItem.item.price * storedItem.qty;
console.log("item from database",storedItem)
this.totalPrice += storedItem.item.price;
}
}
};
1 answers
Answer question0
You can use the express-session package to store session data on the server-side per session/user:
const session = require("express-session");
app.use(session({
secret: "some secret"
}));
app.post("/add-to-cart/:id", async (req, res) => {
try {
// fetch your data
const id = req.params.id,
{ data } = await axios.get("http://localhost:4200/products"),
singleProduct = await data.find((product) => product._id === id);
// create/get a cart
let cart;
if (!req.session.cart) {
cart = new Cart({});
} else {
// req.session does not save the Cart object, but saves it as JSON objects
cart = new Cart(req.session.cart);
}
req.session.cart = cart;
cart.addProduct(singleProduct);
res.redirect("/");
} catch (error) {
console.log(error);
}
});
Then, if the client needs to fetch the cart data, you can create a path for that:
app.get("/get-cart", (req, res) => {
const cartData = req.session.cart || {};
res.send(JSON.stringify(cartData));
});
In the code you provided, I also noticed some issues with your Cart class.
When setting your default values of totalQty and totalPrice, you use oldCart.totalQty || oldCart.totalQty==0.00, which will set it to the totalQty, or a boolean which checks if the totalQty is 0.00.
Also, your addProduct function checks if storedItem is falsey/truthy, which it will always be truthy (default value = {}), result in your logic using an empty object for your item, and resulting in prop of undefined errors.
To fix this: do something like:
module.exports = function Cart(oldCart) {
this.productItems = oldCart.productItems || {};
this.totalQty = oldCart.totalQty || 0;
this.totalPrice = oldCart.totalPrice || 0.00;
this.addProduct = function(item) {
let storedItem = this.productItems;
if (!storedItem.hasOwnProperty("item")) {
storedItem = this.productItems = {item: item, qty: 1, price: item.price};
this.totalQty = 1;
this.totalPrice = item.price;
} else {
storedItem = {item: item, qty: storedItem.qty, price: storedItem.price};
console.log("STORED ITEM: ", storedItem);
this.productItems = storedItem;
storedItem.qty++;
storedItem.price = storedItem.item.price * storedItem.qty;
this.totalQty++;
this.totalPrice += storedItem.item.price;
}
}
}