How to add values in Thymeleaf variable in the loop and after complete loop display final value

Question

I am design bill for products, I want to display all products in thymeleaf template using table and at last, out of loop I want to display sum of price of all products in thymeleaf. how can I define global variable and do it?

<table th:with="totalPrice=0">
    <tr th:each="count,iterator: ${product.paidService}">
        <td th:text="${iterator.index+1}"></td>
        <td th:text="${count.name}"></td>
        <td>Paid</td>
        <td th:text="${count.price}"></td>
        <p th:with="totalPrice=${totalPrice + count.price}"> </p>
    </tr>
    <span th:text="${totalPrice}"></span>
</table>

I am geeting 0 as output but I want sum of all products price as output.

How to make variable global and solve my problem?

Solution

In general you can't change a variable once it's been defined with th:with. They just aren't designed to be used that way. Rather, they are simple temporary variables.

Thymeleaf also doesn't have the concept of global variables. The closest you get to that are attributes you've placed on the model.

You can use collection projection for this:

<table>
    <tr th:each="count,iterator: ${product.paidService}">
        <td th:text="${iterator.index+1}" />
        <td th:text="${count.name}" />
        <td>Paid</td>
        <td th:text="${count.price}" />
    </tr>

    <tr>
        <td colspan="3" />
        <td><b th:text="${#aggregates.sum(product.paidService.![price])}" /></td>
    </tr>
</table>

(General style comments. If you want to do thymeleaf stuff, but don't want to output anything you should be using <th:block /> -- rather than placing <p /> or <span /> tags directly in tables rows.)